1
Q
What 3 things is the nervous system responsible for in general?
A
- Collects information about our environment
- Creates (and interprets) and internal subjective representation of the world
- Unique aspect of the brain - Produces (hopefully appropriate) behaviour, depending on environment
2
Q
What is behavioural neuroscience in general?
A
The field of study that relates behaviour to biological processes.
3
Q
Behavioural neuroscience is also known as…
A
Biological psychology
3
Q
What is behavioural neuroscience primarily interested in? (2)
A
- How the brain REGULATES behaviour
- i.e. how the brain alters behaviour output - How behaviour and experience can affect the brain
- i.e. how learning something affects how we act differently from others who haven’t previously learned the same thing
4
Q
What is neuroscience as a whole?
A
The study of the brain
5
Q
What is ethology?
A
Behavioural neuroscience for animals
6
Q
What are the 8 levels of analysis in behavioural neuroscience?
A
- Social level
- Organ level
- Neural systems level
- Brain region level
- Circuit level
- Cellular level
- Synaptic level
- Molecular level
7
Q
True or false: the levels of analysis in behavioural neuroscience are all integrative (serve to unify separate things)
A
True
8
Q
Because all animals species are related… (2)
A
- So too must be their nervous systems
- Their behaviour must also be related
9
Q
The nervous system and behaviour in complex animals evolved from ____ and depends on ___
A
Simpler systems and behaviours (bit by bit over time)
Learning
10
Q
What 3 tasks are faced by all living things
A
- Secure energy and essential nutrients
- Avoid damage or harm (repair is very costly)
- Secure conditions for reproduction
11
Q
How is evolution through natural selection defined (in this class…)
A
Trying out new variations and keeping the good while throwing away the bad
12
Q
All life evolved from…
A
A common ancestor (LUCA)
13
Q
True or false: humans are special
A
False: humans are not special, we are just animals
- We have a unique evolutionary history that has culminated in a specific set of abilities (including our cognitive abilities)
14
Q
What evidence do we have that all life evolved from a common ancestor?
A
Living organisms appear to be modifications of a general plan (common features), rather than a unique solution for each need (i.e. you can see evolution in progress)
15
Q
What is an example of a commonality between several organisms?
A
The vertebrate forelimb (almost all vertebrates have the same basic skeletal pattern)
16
Q
What two things does the evolutionary approach to behaviour examine?
A
- Species-specific behaviour
- Continuity/conservation of behaviour
17
Q
How does evolution/natural selection relate to neuroscience?
A
Evolution and natural selection changes traits, but retains the same basic plan.
Neurons are found in all animals, and work in the same basic way (neurons are very old adaptations)
18
Q
What is plasticity when referring to a trait?
A
Traits can change over time to adapt to particular environments (that also changes)
19
Q
What 3 facts is evolution by natural selection based on?
A
- Individuals of a given species are not identical
- Some of this variation can be inherited
- Not all offspring survive
20
Q
What is the inference made from the three facts of evolution by natural selection?
A
Variation among individuals affects the probability that they will survive, reproduce and pass along their characteristics
21
Q
True or false: Darwin proposed a mechanism for inheritance
A
False, he just noted that offspring shared parents’ traits
22
Q
What did Mendel define?
A
The laws of inheritance for sexual reproduction: genes come in pairs and are inherited as distinct units, once from each parent
23
Q
What did Hugo de Vries define?
A
The mechanism of mutation that leads to novel traits (good or bad), which is required for evolution
24
How many genes are in the human genome?
~20,000
25
True or false: We have 2 copies of almost every gene
True (except for the gametes)
26
What is the Linnaeus system of classification based on?
Morphology
27
True or False: the Linnaeus system accurately reflects evolutionary history
False
28
What is the Linnaeus system?
Kingdom, phylum, class, order, family, genus, species
29
Describe modern taxonomy and what it's based on
Comparing DNA
Based on spontaneous mutation rate, which predicts how long ago two species diverged
30
True or false: debates continue on modern taxonomy
True, on which phylogenies are best and what species fits where
31
Earth formed ___ years ago
4.5 billion
32
How long ago is LUCA dated back to?
3.5 billion years ago
33
The first nervous system evolved ___ years ago
700 million years ago
34
The first "brain" evolved ___ years ago
250 million years ago
35
The first human-like brain evolved ___ years ago
3-4 million years ago
36
The modern human brain evolved ___ years ago
1-200,000 years ago
37
What are the brain's functional unit? What do they generate?
Neurons, which generate electricity to receive, process, integrate and relay information
38
What other non-neuronal cells are in the brain?
Glia, which still play an important role
39
What 3 components make up the "neuron doctrine"?
1. Nervous systems are made up of discrete individual, polarized (nerve) cells called neurons.
2. Neurons contact each other at specialized junctions called synapses
3. Together, neurons form the developmental, functional, structural and trophic units of nervous systems
40
True or false: each neuron has one synapse
False; neurons have several synapses
41
Who was Anthony van Leuuwenhoek and what did he postulate?
Inventor of the microscope who saw fluids in brain samples
- He postulated that nerves are tubes containing fluids (spirits) carrying sensations from and to the brain
42
What did Jan E. Purkinje do?
Identified the existence of cells in the nervous system
43
What did Theodor Schwann do?
He enunciated cell theory
44
What did Augustus Waller do?
He discovered the concept of antrograde nerve degeneration.
45
What did B.A Gudden do?
Discovered the concept of trophic support (nutrients for neurons). Traced connections between the main centers of the brain.
46
What did Albrecht von Kolliker do?
Supplied proof that nerve fibers are continuous with nerve cells
47
What 3 men were most involved in the "neuron doctrine"?
1. Santiago Ramón y Cajal
2. Camille Golgi
3. Heinrich Wilhelm Gottfried vin Waldeyer-Hartz
48
Who created the modern compound light microscope?
Santiago Ramón y CAJAL
49
Camille Golgi contribution to the neuron doctrine?
Developed the Golgi stain
50
Describe the Golgi stain
A new, yet imperfect stain for different types of neurons
- imperfect because it shows neurons, just not all of them.
51
What is the big controversy in the neuron doctrine?
Reticulistas theory: neurons form a continuous network ("reticulum, DIRECT CONTACT")
vs.
Neuronistas: Neurons are discrete cells (indirect communication)
52
Camille Golgi believed in which theory?
Reticulistas
53
Santiago Ramón y Cajal believed in which theory?
Neuronistas (winners)
54
What are the 4 central tenets of the neuron doctrine?
1. The neuron is a fundamental structural, developmental, functional and metabolic unit of the nervous system
2. Neurons are discrete cells which are not continuous with other cells
3. The neuron is composed of 3 parts - the dendrites, a single axon and a cell body
4. Information flows along the neuron in one direction (from the dendrites to the axon, via integration in the cell body)
55
Define a synapse
A barrier to transmission exists at the site of contact between two neurons that may permit transmission
56
What is the unity of transmission?
Synaptic contacts between two cells can be either excitatory or inhibitory, but WILL ALWAYS BE OF THE SAME TYPE
57
What is Dale's law?
Each terminal releases a single type of transmitter (can be neurotransmitters, or neuropeptides) that bind to receptors
58
Which 3 people were responsible for the later additions to the neuron doctrine (synapses and transmitters)?
1. Otto Loewi
2. Sir Henry Dale
3. Sir Charles S. Sherrington
59
What 2 questions remain regarding neuroscience (that we talked about in class)?
1. Did neurons evolve multiple times (i.e. for different species)?
2. What is a neuron and what constitutes a brain (don't know if our working definition of neurons and brains are accurate)
60
True or false: Only one of the 5 kingdoms of life has a nervous system
True; most living organisms currently or in the past did not have nervous systems, but can still respond to the environment/change their behaviour
61
Which of the 5 kingdoms has a nervous system?
Animalia
62
Describe the evolution of nervous systems in steps
1. Nerve net: simple nervous system, organized as a net with no brain
- Sea anemone
2. Segmented nerve trunk: bilaterally symmetrical organization
- Flatworm
3. Ganglia: structures that resemble and function somewhat like a brain
- Squid
4. Brain: true brain and spinal cord
- Vertebrates
63
True or false: There's an association between the complexity of the nervous system and what a species can accomplish
True
64
True or false: There is a wide variety of nervous systems
True
65
What is neuroplasticity/brain plasticity?
All nervous systems have the ability to modify, change and adapt both structure and function throughout life and in response to experience (rewire, makes new connections)
- helps organisms adapt to their environment, but does have a limit
66
Which phylum has a true "brain"?
Chordate
67
The chordate contains...
Both a mass of nerve tissue in the anterior end of an organism (brain), and a spinal cord
68
The brain consists of which two main parts?
The cerebrum and the cerebellum
69
The cerebrum has _ hemispheres
2
70
True or false: there is a wide variety of brain sizes
True
71
Brain complexity USUALLY mirrors...
Behavioural complexity
72
Why does brain complexity usually mirror behavioural complexity?
Largely due to a proportionally larger cerebral cortex
73
What 3 subphyla are chordates divided into?
1. Vertebrate (fish, amphibians, reptiles, birds and mammals)
2. Tunicata or uruchordata (sea squirts, salps)
3. Cephalochordata (which includes lancelets)
74
All vertebrates share the same basic features. What are 6 of these features?
1. Develops from a hollow tube (neural tube)
2. Bilaterally symmetrical (morphologically, not necessarily functional)
3. Segmented (spinal cord)
4. Hierarchical control
5. Separate systems (CNS vs PNS)
6. Localization of function
75
Usually larger bodies = (smaller/larger) brains
- Provide an exception
Larger
- Exception: humans
76
True or false: all mammalian brains have the same main structures
True
77
All mammalian brains have the same main structures, including... (3)
1. Brain areas
2. Types of cells
3. Similar organization
78
What are the 3 main differences between mammalian brains?
1. Size (cells, brain, areas, cortex, olfactory bulb - dogs have a bigger one)
2. Number of cells
3. Density of cells
79
How do seed catching and non-seed catching seeds compare in terms of neuroscience evolution?
Food-storing birds have a larger hippocampus, which involved in learning and memory because they have to remember where they hid seeds.
They also have a larger telencephalon, which is correlated to motor function
80
Explain the corvid example of neuroplasticity
Corvids have good problem-solving skills because they have evolved to have proportionally larger forebrains than other bird species
81
Describe convergent evolution in songbirds
23 orders of birds, only 3 learn songs
- Through convergent evolution. Same solution, use the same areas of the brain. These areas are larger in birds that learn songs
82
As a rule of thumb, the relative size of a brain area indicates what?
The importance of underlying behaviour
83
What has been the most prominent change in mammal brain size over the last 100 million years?
Brain size
84
True or false: There has been a prominent change in primate brain size in the last 2 million years
True
85
True or false: we evolved from chimps
False; we did not evolve from chimps, chimps and humans evolved from a common ancestor
86
What are the two approaches to studying ancestral brains?
1. Endocasts
- Filling fossils (skulls) to figure out size/shape of the brain
2. Examine species that have changed little since ancient times (e.g. salamanders, opposums)
87
What is the advantage of examining species that have changed little since ancient times over using endocasts?
Can't determine behaviour based on endocasts
87
What is convergent evolution and what is an example of this in neuroscience?
Similar solutions that appeared independently
- e.g. big brain
87
What is found when looking at the lamprey, the most primitive vertebrate?
The lamprey has the same basic structures as us, except for having a very small cerebellum (which is related to motor control and sensory processing)
- Only gets larger in birds and mammals
88
What is the main difference between animal brains?
The relative size and complexity, not in the parts of the brain
89
True or false: There is a direct correlation between the body size and brain weight as a percentage of body weight
False; it is an inverse relationship (mostly)
- smaller animals tend to have a higher % brain weight
90
What is encephalization?
A concept implying an increase in brain size relative to body size. IT IS ASSOCIATED WITH THE EVOLUTION OF THE BRAIN AND INTELLIGENCE
91
How to measure encephalization factor?
- Plot brain weight vs. body weight for a given species
- Encephalization factor is the distance from the average line
- Average line has same slope for each class, just lower
92
Which species has the highest encephalization factor? What does this mean?
Humans
Very large increase in brain size relative to body size, associated with our intelligence
93
All vertebrates have a cortex. What is the trend seen in more recent classes of vertebrates?
The cortex is progressively larger and more complex in more recent classes of vertebrates
94
In general, (smaller/bigger) is better in terms of overall brain size and specific regions
Bigger
- Relates to more complex abilities
95
True or false: on a very general sense, as the brain size increases, so does the size of the individual parts
True
96
Other than brain size, what other factors of the brain influence performance? (5)
1. Folding
2. Neuron density (miniaturization=an extreme reduction in the size of neurons and entire nervous systems in certain animal lineages, driven by the need to fit within a small body volume)
3. Circuit architecture (of neurons)
4. Adaptations at subcellular level (e.g. changes in synapse function)
5. Novel neuron specializations
97
How does folding increase neural performance?
Increases surface area
98
Explain the example of dendritic spines as for how variations in subcellular architecture can influence behaviour
Humans have longer dendritic spines than mice
99
Explain the example of synapse number as for how variations in subcellular architecture can influence behaviour
Humans have increased number of synapses in the cortex than mice and rats
100
Some animals have very rudimentary vision, while others have more complex vision. Where are these abilities reflected?
These abilities are reflected in the complexity of visual processing in areas of the brain
- e.g. lamprey's visual processing area is only in the midbrain, amphibians and reptiles and in the midbrain and tectum, while birds and mammals are in the midbrain, tectum and cortex
101
When/where did Homo habilis (handy human) evolve, and what did they make?
2 million years ago in Africa
- Made simple stone tools
102
When/where did Homo erectus (upright human) evolve, and what did they make?
1.6 million years ago in Europe and Asia
- Made more sophisticated tools than H. habilis
103
True or false: Examining extinct hominids reveals adaptations and selective pressure that led to the evolution of our species
True
104
True or false: structure and behaviour did not evolve simultaneously in our ancestors
True
105
What was the order of evolution for the following traits in humans:
- Body morphology
- Tool use
- Bipedalism
Body morph, bipedalism, tool use
106
True or false: Homo sapiens experienced an exponential growth in crania and brain size
True
107
Describe the brain of Autralopithecus africanus
It was ~350 to 400 cm^3, about the same size as that of living nonhuman apes (chimps)
- Succeeding members of the human lineage display a steady increase in brain size
108
Australopithecines walked (bipedally/quadrapedally)
Bipedally
109
How did Australopithecines use tools? What impact did this have on their face?
Used crude stone tools to cut meat from bones
Reduced size of jaw and teeth
110
True or false: Australopithecines had social groups
True
111
True or false: Australopithecines were nomadic
True
112
True or false: Australopithecines hunted and gathered
True
113
Describe the brain volume of Homo erectus and how it compares to modern brain size
Brain volume ~700 to 1400 cm^3, modern human brain size is ~1400 cm^3
114
Homo erectus tool-use?
Made and used elaborate stone tools
- Made fire
115
Homo erectus hunted large animals. What did this require?
Cooperative groups
116
Homo erectus ranged throughout...
Europe and Asia
117
How did Homo erectus relate to novel environmental conditions?
Wider behavioural capacity allowed them to overcome novel environmental challenges
118
When did the brain size reach the modern plateau?
About 150,000 years ago
119
When did the modern brain triple in size?
About 1.5 mya
120
When did modern human behaviour start to appear?
- What examples of modern human behaviour?
About 10,000 years ago
- Agriculture and domestication of animals
- Cities (5500 years ago)
121
Primates (and some other animals) with large brains or large "executive" brains are more likely to exhibit which behaviours? (3)
- Innovation
- Use of tools
- Social learning
122
True or false: only primates with large brains can carry out observational learning
False; the octopus was capable of observational learning even if they don't have a large brain like primates
123
The brain and nervous system are made up of which cell types (2)?
1. Neurons
2. Support cells
124
In general, how are nervous system cells organized?
Into circuits and networks
125
Describe a neuron in three points
1. Collects information
2. Integrates and transforms info
3. Distributes the processed electrical signal
126
True or false: neurons lack most organelles (compared to other cell types)
False; neurons have the same basic parts as every other cell type
127
Rostral
Toward the front of the brain or the top of the spinal cord
128
Caudal
Toward the back of the brain or the bottom of the spinal cord
129
Ventral
Toward the bottom of the brain or the front of the spinal cord
130
Dorsal
Toward the top of the brain or the back of the spinal cord
131
Horizontal plane
Cutting horizontally through brain
132
Sagittal plane
Cutting longitudinally (left and right, separating brain into hemispheres)
133
Coronal plane
Cutting into anterior and posterior (halfway through brain, separating belly and back)
134
What is the point of cutting the brain in different orientations?
Depending on how you cut the brain, you will get different info on the structures/functions of the brain
135
Structures atop the brain or a structure within the brain are...
Dorsal
136
Structures toward the bottom of the brain or one of its parts are...
Ventral
137
Anterior
In front of; toward the face
138
Posterior
Behind; toward the back
139
Medial
Structures toward the brain's midline
140
Lateral
Structures toward the sides
141
Contralateral
On other side relative to something else
142
Ipsilateral
On the same side relative to something else
143
Superior
Above; toward the head
144
Inferior
Below; toward the feet
145
The nervous system is separated into... (2)
1. Central nervous system (CNS)
2. Peripheral nervous system (PNS)
146
The central nervous system (CNS) is separated into... (2)
1. Brain
2. Spinal cord
147
The peripheral nervous system (PNS) is separated into... (3)
1. Somatic nervous system
2. Autonomic nervous system
3. Enteric nervous system
148
True or false: Research has shown that the enteric system has extensive communication with the CNS
True
149
The CNS consists of... (2)
1. Brain
2. Spinal cord
150
Describe the surface of the brain
Complex, with sulci/gyri and lobes (4) + fissures
151
Sulci
Grooves (peak)
152
Gyri
Folds (trough)
153
The brain is composed of two hemispheres, and each cerebral hemisphere contains which 4 lobes?
1. Frontal
2. Parietal
3. Temporal
4. Occipital
154
True or false: the brain is symmetrical in all aspects
False; on a large scale, the brain is mostly anatomically symmetrical. However, there is functional asymmetry
155
Describe the two examples of functional asymmetry that we discussed
Speaking and language is on the left side of the brain, while spatial navigation is usually on the right side
156
Analytical thought, detail orientation, math/science, logic and rational thought are lateralized on which side of the brain?
Left
157
Intuitive thought, holistic perception, creativity, imagination, and emotional intelligence is lateralized on which side of the brain?
Right
158
Each hemisphere controls the (same/opposite) side of the body
Opposite
159
True or false: Each half of the brain receives input from and sends output to half of the body
True
160
What is gray matter in the brain?
Areas of the nervous system predominantly composed of cell bodies and blood vessels
161
What is white matter in the brain?
Areas of the nervous system rich in fat-sheathed neural axons
162
What is the corpus callosum
Fiber system connecting the 2 cerebral hemispheres
163
The internal structure of the brain is composed of what 3 things that we discussed?
1. Ventricles (produce/circulate CSF)
2. Fiber bundles (bundles of axons)
3. Nuclei (condensation of neurons/cell bodies with a particular function and similar morphology)
164
The forebrain is composed of which two parts?
1. Telencephalon
2. Diencephalon (although not everyone includes Diencephalon in the forebrain)
165
What is the telencephalon made of? (3)
1. The isocortex
2. The basal ganglia
3. The limbic system
166
What is the largest portion of the brain?
The forebrain
167
What is the diencephalon made of? (2)
1. Thalamus
2. Hypothalamus
168
What is the meSencephalon also known as?
The midbrain
169
What is the hindbrain made of? (2)
1. Metencephalon
2. Myelencephalon (medulla)
170
What is the meTencephalon IN THE HINDBRAIN made of? (2)
1. Cerebellum
2. Pons
171
What is the brainstem made of? (2)
Midbrain + hindbrain (- cerebellum)
172
What is phrenology?
The idea that certain brain areas have localized, specific functions or modules (Gall, Penfield, Broca, Wernicke)
173
What is the aggregate field theory?
The brain acts as a single functional unit (mass action; Flourens, Lashley)
174
What is the current view of function localization?
The mass action principle (aggregate field theory) is accepted as a mechanism for SOME functions within the brain. However, there have been other functions that are believed to be contained within specific areas of the brain.
175
Particular functions are often attributed to specific regions of the brain, however... (2)
1. Some structures can serve more than one function
2. Some (complex) functions can involve several regions (e.g. learning)
176
What does function localization depend on?
The level of function (simple programs vs complex function, e.g. detection of thirst vs. learning)
177
What are the 3 principle pairs of nuclei in the basal ganglia?
1. Caudate nucleus
2. Putamen
3. Globus pallidus
178
What are the 2 associated pairs of nuclei in the basal ganglia?
1. Subthalamic nucleus
2. Substantia nigra
179
What is the main function of the nuclei in the basal ganglia?
Motor control (voluntary and involuntary)
180
What happens if the basal ganglia is dysfunctional?
Can lead to neurological diseases related to movement, such as Parkinson's or Tourette's syndrome.
181
What 8 areas are found in the limbic system and Diencephalon?
1. AMYGDALA
2. HIPPOCAMPUS
3. HYPOTHALAMUS
4. THALAMUS
5. Cingulate cortex
6. Fornix
7. Olfactory bulb
8. Mammillary bodies
182
What 4 things are the limbic system and diencephalon primarily involved in?
1. Emotion
2. Learning
3. Attention
4. Smell
183
True or false: the limbic system and diencephalon control emotional responses that are important for behaviours needed for survival, such as feeding, reproduction and caring for young, and fight/flight
True
184
Describe the diencephalon structure and location
Located deep within the brain and connects midbrain with the forebrain
185
What is the general structure and main function of the thalamus in the diencephalon?
Lots of nuclei, filters sensory input and outputs to cortex
186
What is the general structure and main function of the hypothalamus in the diencephalon?
Many nuclei, involved in homeostatic and endocrine functions
187
What is the main function of the brain stem (composed of the midbrain and hindbrain, minus the cerebellum)?
Connects the brain (cerebrum) to the spinal cord
188
What 2 parts does the meSencephalon in the hindbrain split into?
2 pairs of bumps on the back of the brain stem
1. Superior colliculus
2. Inferior colliculus
(and also substantia nigra)
189
What structure is part of both the midbrain and the basal ganglia?
The substantia nigra
190
A ___ nucleus is found in the midbrain, which composes...
Red, the motor neurons in the spinal cord
191
The midbrain forms the start of the...
Reticular formation
192
What is the reticular formation important for? (4)
1. Sleep
2. Arousal
3. Temperature
4. Motor control
193
What are the main functions of the pons in the metencephalon? (which is in the hindbrain) (2)
1. Motor and sensory functions
2. Input from some cranial nerves
194
What are the main functions of the medulla in the metencephalon? (2)
1. Input from cranial nerves regulating neck and tongue
2. Regulates breathing and the heart
195
Describe the general structure of the cerebellum in the hindbrain (metencephalon) (2)
- Highly folded structure
- Many tightly packed neurons
196
What specific type of cell is found in the cerebellum?
Purkinje cells (very branched)
197
What is the cerebellum involved in?
Motor control (fine motor movements, like writing) and various cognitive functions (learning and memory)
198
The cerebral cortex is often called the...
Neocortex
199
The cortex is (well/poorly) developed in birds and mammals
Well
200
True or false: the cortex was recently evolved
False; this is an old belief
All vertebrates have a neocortex, even if it is quite small and simple in fish, amphibians and reptiles
201
How many layers are in the cortex?
6
202
What is the allocortex also known as?
Archicortex
203
Where is the allocortex located in general, and how many layers does it contain?
Under the neocortex, 3
204
The allocortex (archicortex) is made of what two things?
1. Hippocampus
2. Olfactory bulb
205
The cerebral cortex is mainly responsible for...
Cognition
206
What happens if someone has a lack of activity in the cerebral cortex?
Declared brain dead
207
Describe the general structure of the cerebral cortex
Cerebral cortex=brain surface
6 layers of grey matter on top of white matter with well-developed functions
208
Where is the limbic cortex (limbic system) found?
In the cerebral cortex
209
What is the limbic cortex made of?
3-4 layers of grey matter
210
The cortex makes up __% of the forebrain
80
211
What is the surface area of the human cortex, and what causes this number?
2500 cm^2 because it's heavily folded
212
What is the thickness of the human cortex?
1.5-3 mm
213
What do layers 1, 2 and 3 of the cerebral cortex grey matter control?
Integrative functions (receive input that is sent deeper into the brain)
214
What does layer 4 of the cerebral cortex grey matter control?
Input of sensory information
215
What do layers 5 and 6 of the cerebral cortex grey matter control?
Output to other parts of the brain
216
How are distinct regions of the cortex defined?
Based on the anatomy of the layers
217
What are cortical columns?
Cohesive processing units, where all cells within a column respond to the same stimulus
218
Adjacent cortical columns respond to...
Slightly different stimuli
219
True or false: the cortical columns span the entire thickness of the cortex
True
220
Most of the cells in cortical columns make connections (vertically/horizontally)
- explain
Vertically within the column
- Some horizontal (between adjacent columns)
221
True or false: cortical communication is restricted to short local connections within each hemisphere
False; cortical communication consists of short local connections, long connections within each hemisphere, crossing over to the other hemisphere through the corpus callosum and multistep communication through the thalamus/basal ganglia
222
The CNS has multiple levels of function. What does this reflect to an extent?
Phylogeny (evolutionary development and diversification of a species)
223
True or false: there is duplication of control at various levels of the CNS (redundancy)
True
224
The CNS has multiple levels of function. Rank the three levels of control in terms of lowest to highest control
What do each provide?
1. Spinal cord (basic control)
2. Brain stem (more flexibility/plasticity)
3. Cortex (highest level of plasticity)
- Each provides refinement and elaboration of control
225
True or false: multiple levels of control exist within the cortex
True; primary vs. secondary cortices
- some cortices are considered "higher level" than others
226
The more complex the function, the (lesser/greater) its distribution over many regions in the brain
Greater
227
The more specific the function, the (lesser/greater) its distribution over many regions in the brain
Lesser
228
Describe the localized and distributed function of vocalization (3)
1. Control of the larynx
2. Language comprehension and production
3. Complex language function (poetry, songs)
ALL CONTROLLED BY DIFFERENT AREAS OF THE BRAIN
229
In the CNS, when axons run along together, they form a...
Tract
- Collection of axon fibers within the CNS
230
In the PNS, when axons run along together, they form a...
Nerve
- Bundle of fibers outside the CNS
231
What are the three divisions of the PNS?
1. Cranial nerves
2. Spinal nerves (somatic nervous system)
3. Autonomic nervous system
232
All divisions of the PNS...
Receive info from the CNS and send info to the CNS
233
How many pairs of cranial nerves are there?
12
234
True or false: Cranial nerves come in pairs, with one on each side of the brain midline
True
235
What is the main function of the cranial nerves?
Input and output for sensory organs and face
236
True or false: cranial nerves each deal with 1/2 of the face, contralaterally
False; cranial nerves each deal with 1/2 of the face, on the same side (ipsilaterally)
237
What is the oculomotor cranial nerve responsible for?
Eye movement
238
What is the trochlear cranial nerve responsible for?
Eye movement
239
What is the trigeminal cranial nerve responsible for?
Masticatory movements and facial sensation
240
What is the abducens cranial nerve responsible for?
Eye movement
241
What is the facial cranial nerve responsible for?
Facial movement and sensation
242
What is the auditory vestibular cranial nerve responsible for?
Hearing and balance
243
What is the glossopharyngeal cranial nerve responsible for?
Tongue and pharynx movement and sensation (speaking, eating, swallowing)
244
What is the vagus cranial nerve responsible for?
Heart, blood vessels, viscera, movement of larynx and pharynx
245
What is the spinal accessory cranial nerve responsible for?
Neck muscles
246
What is the hypoglossal cranial nerve responsible for?
Tongue muscles
247
What is the only cranial nerve not involved with the face?
The vagus nerve
248
Except the ___ nerve and the ___ nerve, the cranial nerves emerge from the ___.
Olfactory, optic, brainstem.
249
Where do the olfactory nerves emerge from?
The olfactory bulbs
250
Where do the optic nerves emerge from?
The lateral colliculus, swellings on either side of the temporal lobes
250
How many pairs of spinal nerves are there?
31
251
How many cervical spinal nerves?
8
252
How many thoracic spinal nerves?
12
253
How many lumbar spinal nerves?
5
254
How many sacral spinal nerves?
5
255
How many coccygeal spinal nerves?
1
256
What is the order of the spinal nerves?
Cervical, thoracic, lumbar, sacral, coccygeal
257
Each spinal nerve has _ roots, which are the...
2
- Dorsal
- Ventral
258
What is the Bell-Magendie law?
- The dorsal roots relay sensory information (afferent)
- The ventral roots relay motor information (efferent)
259
Sensory info comes through the __ regions
In the spinal cord, this is ___
In the midbrain, this is ___
Dorsal regions
- Dorsal horn
- Colliculus
260
Motor info goes through the __ regions
In the spinal cord, this is __
In the midbrain, this is __
Ventral
Ventral horn
Tegmentum
261
What are the exceptions to the Ball-Magendie law?
The thalamus and the cortex, as they have specific sensory and motor nuclei and regions
262
Where is the autonomic nervous system found in general?
Spans the PNS and the CNS
263
How is the autonomic nervous system controlled outside the CNS?
Within collections of neurons (ganglia)
264
How is the autonomic nervous system controlled within the CNS?
Controlled by autonomic neurons
265
What are the two main divisions of the autonomic nervous system?
1. Sympathetic (fight or flight)
2. Parasympathetic (rest and digest)
266
Describe the physiology of the sympathetic nervous system in general
Cell bodies of autonomic neurons are located in the spinal cord. Axons exit the spinal cord at thoracic and lumbar regions, innervating (talking to) neurons in sympathetic chain adjacent to spinal cord
267
Describe the physiology of the parasympathetic nervous system in general
Originate in cranial or sacral regions. Ganglia containing neuronal cell bodies close to target organ.
268
What are the meninges in general?
The brain is surrounded by protective tissue called the meninges (cushion, support and protect the brain)
269
What are the 3 layers of meninges?
1. Dura mater
2. Arachnoid
3. Pia mater
270
Describe dura mater in the meninges
"Tough mother"
- Tough connective tissue that surrounds the brain like a sack (immediately under the skull)
271
Describe arachnoid in the meninges
Thin delicate membrane that follows the contours of the brain
272
Describe pia mater in the meninges
Delicate tissue that clings to the surface of the brain
273
What is found between the arachnoid and pia mater?
Cerebrospinal fluid (CSF)
274
Function of CSF?
With the meninges, it cushions, supports and protects the brain. Also nerves as nutrients and waste management
275
Describe the general structure of the ventricles
4 interconnected compartments
276
Describe the functions of the ventricles (2)
1. Waste and management system
2. Cushion and support the brain
277
What is CSF produced by?
The choroid plexus (complex network of capillaries lined by specialized cells) in the lateral ventricles
278
Describe the flow of CSF
Flows through the ventricular system and then exits CNS
279
The brain is about _% of the body, but uses _% of blood
2, 20
280
What is the circle of Willis?
Provides collateral blood flow between the anterior and posterior circulations of the brain (ensuring continuous blood flow to the brain even if one of the major blood vessel pathways becomes blocked or damaged)
281
Where does the anterior cerebral artery feed blood to?
Top and front of brain
282
Where does the middle cerebral artery provide blood to?
Sides of brain
283
Where does the posterior cerebral artery provide blood to?
Back/bottom of brain
284
What is a stroke?
The sudden and severe interruption of blood flow
285
What is the blood-brain barrier?
Tight walls of capillaries exist in the brain (not 100% closed), which protects the brain from toxins and infection.
286
What is a limitation of the blood-brain barrier?
Makes it harder to get drugs and nutrients to the CNS
287
True or false: the blood brain barrier may be compromised with stress and certain diseases
True; like in Alzheimer's
288
How can we infer the function of neural cells?
Based on their location, shape and their parts.
289
How are cells of the nervous cells visualized? (3 steps)
1. Fix tissue (add chemicals to the brain like formaldehyde to kill tissue but preserve structure)
2. Make thin slices
3. Stain it to reveal features of different cell types
290
Tissue fixation consists of what two steps?
1. Cessation of normal life functions in the tissue (killing)
2. Stabilization of the structures of the tissue (preservation)
291
How can we look at physiological features of the cells of the nervous system? What is an example of a physiological feature?
Unfixed (i.e. live) tissue (e.g. electrical activity, action potentials)
292
Golgi body function?
Membranous structure that packages protein molecules for transport
293
Lysosome function?
Sacs that contain enzymes that break down wastes
294
Axon function?
Transmits information from cell body to other cells
295
Endoplasmic reticulum function?
Folded layers of membrane where proteins are assembled
296
Dendritic spine function?
Small protrusions on dendrites that increase surface area
297
Dendrite function?
Cell extension that collects information from other cells
298
Which 3 organelles/cell structures are neuron-specific?
1. Dendrites
2. Dendritic spine
3. Axon
299
Inside and outside of a cell is __ fluid
Salt
300
What is the fluid outside a cell called?
Extracellular fluid
301
The cell membrane is a semi-permeable barrier; what molecules can pass through without aid?
Fat-soluble molecules and some gases
302
Phospholipids have a (hydrophobic/hydrophilic) head and a (hydrophobic/hydrophilic) tail
Hydrophilic, hydrophobic
303
What does the phospholipid bilayer separate and prevent?
The two aqueous environments (prevents movement of ECM into cell, and cytoplasm out of cell)
304
What are 5 examples of molecules that can pass through the phospholipid bilayer?
1. NO
2. O2
3. CO2
4. Lipid-soluble hormones
5. Uncharged proteins
305
What are two examples of molecules that cannot pass through the phospholipid bilayer?
1. Small inorganic ions (Na+, K=, Ca2+, Cl-)
2. Charged proteins
305
What are 3 examples of complex model systems used to understand the nervous system?
Mouse, rat, monkeys
306
What are 3 examples of simple model systems used to understand the nervous system?
Snails, worms, flies
307
Describe multipolar neurons
The most common type of neuron, characterized by a single axon and multiple dendrites that extend from its cell body
308
Describe bipolar neurons
A neuron with one axon and one dendrite extending from opposite sides of its cell body
309
Describe monopolar neurons
Monopolar neurons have a simple T-shape, with the cell body located along the nerve fiber.
310
The neuron cell body is also known as...
Soma
311
There is __ axon per neuron, and it starts at the ____
One, axon hillock
312
The axon branches into what two things?
Axon collaterals and teleodendria
313
What are axon collaterals?
Side branches that grow off a neuron's main axon, enabling a single neuron to send signals to multiple other neurons or target cells simultaneously
314
What do teleodendria end with?
A pre-synaptic terminal aka button or boutton
315
How many primary dendrites are there per cell?
1-20
316
True or false: Each dendrite branches numerous times to increase the surface area and increase information receival
True
317
What are the 3 main classes of neurons?
1. Sensory neurons
2. Interneurons
3. Motor neurons
318
What is the main function of sensory neurons?
"Input"; provide information from senses to CNS
319
What type of neuron makes up the majority of neurons?
Interneurons
320
What are the two types of interneurons?
1. Local projection
2. Long-distance projection
321
Describe a local projection interneuron
Projects WITHIN a brain region
322
Describe a long-distance projection interneuron
Projects BETWEEN brain regions
323
What is the main function of motor neurons?
"Output"; signal from CNS to muscles
324
True or false: there are many different types of neurons within each of the three classes
True
325
True or false: the cells of the nervous system are highly variable
True
326
Neurons with long extensions likely...
Relay information
327
Neurons with short extensions likely...
Engage in local processing
328
Complex, bushy dendrites likely...
Integrate information from a wide area
329
Simple dendrites likely...
Integrate on a much smaller scale, act as relays
330
Sensory neurons are efficient __ cells
Relay
331
How many dendrites do sensory neurons contain?
One
332
True or false: The sensory neuron dendrite is quite large
False; it can be small (e.g. bipolar cells in the retina) or large (e.g. sensory neurons for skin)
333
True or false: Sensory neurons can be among the largest in the body
True
334
How are interneurons defined?
Technically every neuron between a sensory and a motor neuron is considered an interneuron
335
What are 3 examples of interneurons?
1. Stellate (star-shaped) cell
2. Pyramidal cell
3. Purkinje cell
336
Describe stellate (star-shaped) cells
Small; many short dendrites extend around the cell body; short axon
337
Describe pyramidal cells
Has a long axon, a pyramid-shaped cell body, and two sets of dendrites. Carries information from the cortex to the rest of the brain and spinal cord.
338
Describe purkinje cells
A distinctive interneuron with extremely branched dendrites that form a fan shape. Carries information from the cerebellum to the rest of the brain and spinal cord. One of the largest cells in the brain.
339
Where are motor neurons located? (3)
In the cerebral cortex, brainstem and spinal cord
340
Motor neurons usually have a (small/large) cell body and (small/large) axon that connects to ____
Large, large, muscles
341
True or false: All efferent (outgoing) neural information must pass through the motor neurons to reach the muscles
True
342
True or false: motor neurons have a single dendrite
False; they have bushy dendrites to collect information
343
Sensory neurons collect (afferent/efferent) information from the body and connect to interneurons that ____ and pass it on to motor neuron (afferent/efferent) connections
Afferent, process the information, efferent
344
What are the 3 organizational aspects of neuronal networks?
Input, association, output
345
True or false: neurons conduct all their incoming signals
False; they are selective
346
The chemical synapse that releases neurotransmitters/neuropeptides to relay the signal is (unidirectional/bidirectional)
Unidirectional
347
Most connections between neurons in an area are...
Local
- e.g. local interneurons
348
How do axon collaterals regulate activity?
Feedback regulation (releases chemicals to turn off neurons or regulate its own activity, which prevents overactivation/hyperactivity)
349
If there is more excitation, the neuron (will/will not) relay the signal
Will
350
If there is more inhibition, the neuron (will/will not) relay the signal
Will not
351
What are the two opposite views on how neurons code for behaviour
1. Each neuron codes for specific aspects of behaviour ("Grandmother cell"
2. Neurons work together in complex networks to code for specific aspects of behaviour
- so the loss of one or more neurons would not affect behaviour, the network can still function
352
Based on evidence, current neuroscience favours the ___ hypothesis for how neurons code for behaviour
Network
353
Describe the simple network behaviour example of the "cricket"
Crickets have a simple behavioural repertoire, some of which can be modeled accurately by a robot
1. Move "cricket" robot towards mate
2. Microphone closest to the mate will be activated more strongly (it's closest to the sound)
3. This makes the wheel opposite it spin faster, which orients the "cricket" towards the mate
4. When the mate is equidistant from both microphones, the "cricket" moves forward
354
Describe the simple network behaviour example of the moth
"Ears" on either side of the moth are connected to wing muscles on opposite side of the body. Side closest to the bat is activated the most, which affects the opposite wing to steer the moth away from the bat
355
Describe the complex network behaviour example of the "cricket"
Crickets also fear light. Add an inhibitory circuit that detects light. Response depends on quality (loudness) of mate and brightness of light. They won't come out in bright light but might come out at dusk if mate is good enough.
- by adding more components, you get a more complex system
356
Can most neurons regenerate?
No; neurons are post-mitotic and most are not replaced
- BUT many neurons can take over, unless essential like the substantia nigra (which leads to Parkinon's)
This means that most neurons live with you throughout your whole life
357
Glial cells are also known as...
Neuroglia
358
What is the range of ratios of glia cells to neurons?
Between a 1:1 and 10:1 ratio with neurons
359
True or false: glial cells are post-mitotic
False; unlike neurons, they are constantly renewed throughout life.
360
True or false: like neurons, glial cells have multiple forms and roles
True
361
What are the 4 main types of glia in the CNS?
1. Ependymal cells
2. Microglia
3. Astrocytes
4. Oligodendrocytes
362
What are the 2 main types of glia in the PNS?
1. Satellite glial cells
2. Schwann cells
363
Describe ependymal cells
These are the cells that line the ventricles, which help generate the cerebrospinal fluid (CSF) and create/assist the flow of the fluid that provide nutrients/remove waste
- They assist with the flow of fluid using cilia
364
What is the function of the microglia?
Immune system and repair in the CNS (clear dead cells, including apoptotic neurons)
- similar functions as white blood cells (monocytes) and macrophages
365
When do microglia get activated?
Describe the 2 steps of activation
When there's an infection in the CNS
1. Non-activated microglia gets activated ameboid form (can move around and extensions are "sucked in"
2. Ameboid form becomes phagocytic microglia (macrophage)
366
Recent evidence shows extensive (and essential) communication between microglia and neurons. How is this communication carried out?
Intimate communication occurs by means of the release of all kinds of chemicals
367
What is the function/structure of astroglia (astrocytes)?
Star-shaped cells that provide structural support and convey nutrients between blood vessels and neurons (past of the blood-brain barrier)
- They also regulate blood flow and can play a role in healing the brain after damage
368
What is the function/structure of satellite cells? (2)
- Small cells that surround neuron cell bodies in the autonomic nervous system (i.e. PNS)
- They resemble the astrocytes of the CNS and assist in regulating the external chemical environment (provide nutrients)
369
True or false: Satellite glial cells are very sensitive to injury and may exacerbate pathological pain
True
370
What is the function/structure of oligodendrocytes?
Myelinate axons in the CNS by branching and myelinating several axon segments of different cells
371
What is the function/structure of Schwann cells?
Myelinate axons located in the PNS. Myelinate only one segment of only one cell (wraps around the axon)
372
What are the 2 main functions of the myelin sheath?
1. Insulates the neurons
2. Speeds up transmission of the neural signal (action potentials jump from node to node)
- Each segment is separated by a small gap called a node of Ranvier
373
True or false: There's still quite a few axons in the nervous system that are unmyelinated
True
374
In the PNS, several myelinated/unmyelinated axons together with blood supply and other connective tissue will form a...
Nerve bundle
375
What is a glioma?
A brain tumour formed by abhorrent glial cells
376
Describe multiple sclerosis
Multiple myelin are damaged, which results in uncontrolled action potential transmission
377
When neurons are injured in the nervous system, this can lead to loss of...
Sensation and movement in the affected area(s)
378
Neurons can be repaired in the (CNS/PNS), but not the (CNS/PNS)
- explain why
PNS, CNS
- Recovery is possible in the PNS because of glia
- Recovery is impossible in the CNS due to the formation of glia scars (astrogliosis, accumulation of glia cells prevent new neurons from regenerating)
379
Describe successful nerve regeneration vs unsuccessful nerve regeneration
Successful nerve regeneration: After injury, macrophages remove debris. Schwann cells regress and divide. They allow for a path along which the axon can regrow. The Schwann cells then remyelinate the new axon.
Unsuccessful nerve regeneration: Overactivation of glia cells result in axonal sprout formation and the part not attached to the cell body degenerating. Macrophages still remove debris, but the neuron is non-functional due to disorganized axonal sprouts
380
What does a protein's function depend on?
Its structure
381
What are proteins essential for?
Structure, function and the regulation of the body's cells, tissues and organs.
382
Describe the 3 steps of protein synthesis (after translation)
1. Proteins formed in the ER enter Golgi bodies, where they are wrapped in a membrane and given a shipping address
2. Each protein is attached to a motor molecule and moves along the microtubule to its destination
3. The protein may be incorporated in the membrane, or be excreted from the cell by exocytosis
383
When bound in membranes, proteins can act as which two things?
1. Channels (gated and non-gated)
2. Pumps
384
Describe the difference between ion channels, gated channels and pumps
1. Ion channels provide a diffusion pathway for charged ions across the plasma membrane
2. A gated channel allows passage of substance when gates are open, and prevents when gates are closed
3. Pumps change shape to carry substances across a cell membrane (either in or out)
385
Proteins change ___ when interacting with other molecules
Their shape
386
Describe receptors
Recognize and bind extracellular signaling molecules and transmit messages across the plasma membrane
387
Describe transport molecules
Pumps and carriers physically move membrane impermeable molecules across the plasma membrane
388
True or false: membrane-bound enzymes are found both on the inside and outside of the plasma membrane
True
389
Describe adhesion molecules
Mediate adhesion between cells or between cells and their environment
390
True or false: a large proportion of our genes are expressed in the brain
True; they underlie the diversity and complexity of neurons
391
True or false: a mutation in a single cell won't have a huge effect on behaviour or physiology, unless it becomes cancerous
True
- And a large part of DNA is non-coding so they have no effect
392
Which two main mutation have a dramatic effect on the gene?
An inversion or substitution of several amino acids
393
What is phenotypic plasticity?
Phenotype results from interaction between genome and environment
394
What 3 things do epigenetics describe?
1. How a single genetic code can produce a different somatic cell type
2. Explains how a single genome can code for many phenotypes
3. Describes how cell functions go astray to produce diseases ranging from cancer to brain dysfunction
395
What are the 3 methods of epigenetic modifications that we discussed?
1. Histone modification
2. DNA methylation
3. mRNA modification
396
Who described dominant and recessive genes for single locus traits?
Gregor Mendel
397
What is an example of incomplete dominance?
Skin colour
398
What is an example of co-dominance?
AB blood type
399
Describe what causes Tay-Sach's disease, its symptoms and the relative prevalence
Tay-Sach's is a recessive disease caused by non-functional enzyme called hexoaminidase A (HexA) which normally breaks down certain lipids (fats) in the brain.
A buildup of these particular lipids causes seizures, blindness, degenerating motor and mental function and eventually death. There is a higher than average prevalence in French Canadians and descendants of Jewish people from Europe.
400
Why are Tay-Sach's carriers typically normal?
Have enough functional enzyme. Still have elevated brain lipids but not to the point of developing Tay-Sach's
401
Describe what causes Huntington's disease as the symptoms
A dominant disease caused by mutant huntington protein that builds up in cells in the nervous system. This buildup kills brain cells, especially in the basal ganglia and cortex.
- This can lead to memory impairments and dementia. Symptoms can appear over a wide age range, but most often after mid-life, frequently after the person has already had kids and passed the trait on to them
402
True or false: having an extra chromosome can increase your susceptibility to disease
True
403
How can useful models of disease be created?
Can selectively breed spontaneous or induced mutants
404
What is cloning and its overall efficiency? Provide an example
A controlled method of producing organisms with identical genotypes. May be useful to create a large number of animals with identical genotype.
- Not very efficient, because phenotype is not necessarily the same due to environmental factors.
But inbred rodent strains have a nearlyhomogenous genotype so its useful for research purposes.
NEUR 321
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