Unit 1

Question 1

Who was Cajal and what did he contribute? What specific technique helped him make this contribution?

Answer 1

A scientist who found that there was a gap between the synapses by using Golgi stains

Question 2

What are two basic types of cells in the brain and spinal cord?

Answer 2

Neurons & Glia Cells (astrocytes, oligodendrocytes, microglia, radial glia)

Question 3

Structure components of a neuron

Answer 3

Soma, axon, dendrites, myelin, synaptic cleft, axon hillock

Question 4

Internal components of a neuron

Answer 4

Nucleus, ribosomes, mitochondria, endoplasmic reticulum (ER), membrane

Question 5

Describe the cell membrane.

Answer 5

A lipid bilayer that halts most chemicals aside from those with a protein channel (i.e., water, sodium, potassium, calcium,, chloride, etc.)

Question 6

What are dendrites and spines? What is their functional role?

Answer 6

They are lined with synaptic receptors, and they help to receive messages from other neurons. The more spines and dendrites there are, the greater the surface area for synapses

Question 7

Astrocytes

Answer 7

Creates blood-brain barrier, limit where neurotransmitters go

Question 8

Oligodendrocytes

Answer 8

Creates the myelin sheaths along the axon in central nervous system

Question 9

Radial Glia

Answer 9

Help in development for neurons to migrate, can change over time and become different neurons

Question 10

Microglia

Answer 10

Very powerful in removing waste material and signal for immune resins

Question 11

Discuss the blood brain barrier. What is active transport?

Answer 11

Blocks most chemicals, viruses, and bacteria from entering the brain, but also blocks out useful chemicals. Active transport is a protein-mediated process that expends energy to pump chemicals from the blood to the brain.

Question 12

What is the action potential and what does it have to do with neurons?

Answer 12

Also known as a nerve impulse, it is the electrical signal that is transmitted down the axon of a neuron. Within the neuron, it is a rapid depolarization

Question 13

Labels on a nerve impulse graph

Answer 13

1. resting
2. threshold
3. depolarization
4. AP
5. repolarization
6. hyper polarization
7. refractory period
8. resting

Question 14

Describe the electrical gradient. How is it maintained?

Answer 14

The difference of electrical charges between inside and outside the membrane, who maintains the gradient.

Question 15

What is the resting potential? Describe it and state the charge associated with it.

Answer 15

Difference in voltage in a resting neuron that is about -70 mv.

Question 16

What are voltage-activated channels, and how do they work?

Answer 16

Permeability depends on the voltage difference across the membrane. As the membrane depolarizes, sodium rushes in to create an AP while potassium rushes out.

Question 17

What is something that helps to maintain the resting state?

Answer 17

Sodium potassium pump restores ion distribution

Question 18

What is myelin and what makes myelin in the CNS and the PNS?

Answer 18

It is composed of fats and proteins that helps the AP to regenerate at each Node of Ranvier. Oligodendrocytes make myelin

Question 19

Describe salutatory conduction. How do demyelinating disorders disturb this process?

Answer 19

Jumping of an AP from node to node and it provides rapid conduction of impulses & conserves energy. Without the myelin, the axon lacks sodium channels causing most APs to die out between one node and the next.

Question 20

What are local neurons and graded potentials?

Answer 20

Local neurons have short axons and do not produce APs. Instead, they produce graded potentials, a membrane potential that varies in magnitude in proportion to the intensity of the stimulus

Question 21

What are three main contributions that Sherrington made? What term did he coin?

Answer 21

1. Validation of the synapse (term he coined) - reflexes are slower than conduction along one axon
2. Summation - several weak stimuli can produce a stronger reflex
3. Interneuron inhibition - as one set of muscles contracts, the other relaxes

Question 22

How is the vagus nerve related to the brain, the gut, and other organs like the heart?

Answer 22

The gut, also known as the second brain, communicates with the actual brain via the vagus nerve. (Loewi decreases the heart rate of a second frog by stimulating the vagus nerve on the first and transferring that NT to it)

Question 23

Explain temporal and spatial summation. What are EPSPs & IPSPs? What does the axon hillock have to do with EPSPs & IPSPs?

Answer 23

Temporal: repeated stimuli over a time has a cumulative and stronger effect
Spatial: several small stimuli on a similar location produced a reflection when a single stimulus did not
EPSPs: positive grade potential that decays over time and space
IPSPs: synaptic input selectively opens the gates for potassium (+) to leave or for chloride (-) to enter
Summation occurs on the axon hillock

Question 24

State the major categories of NTs.

Answer 24

Amino acids, monoamines, acetylcholine, neuropeptides, purines, gases, nitric oxide

Question 25

What are the steps in the chemical events at the synapse?

Answer 25

1. Synthesis 2. Transported 3. Release with calcium 4. Binds 5. Separates 6. Removed (Diffusion, reuptake, enzymatic degradation) 7. Feedback

Question 26

Describe the process of NT release; use the terms (e.g., vesicles and exocytosis). What is a negative feedback loop?

Answer 26

The AP causes the vesicles to fuse/merge with the membrane which causes the NT to be excreted out through exocytosis. IT is a feedback mechanism that alters activity of the presynaptic neuron

Question 27

Discuss the role of hormones and how they work. Explain the general role of the pituitary gland and the hypothalamus.

Answer 27

They coordinate long-lasting changes in multiple parts of the body by being transported through the blood stream to any receiver tuned in to the right station. The hypothalamus contains the pituitary and causes it to release hormones and maintains fairly constant circulating levels of certain hormones through a neg. feedback system

Question 28

Define the relevant terms (e.g., agonist, antagonist, efficacy, and affinity).

Answer 28

Agonist: mimics or increase the effects of NTs Antagonist: blocks the effects of NTs Efficacy: tendency to activate receptor (key turns lock) Affinity: ability to bind to receptor (key in)

Question 29

Characterize (explain) some of the ways that drugs can alter synaptic activity. What are the terms you learned?

Answer 29

It can: alter the synthesis of NTs, cause vesicles to leak, increase release of NTs, decrease reuptake of NTs, block enzymatic breakdown, stimulate or block receptors

Question 30

Describe Olds and Milner’s experiment.

Answer 30

They placed rats in boxes where they could press a lever to produce electrical self-stimulation of the brain. The rats pressed the lever up to 2000 times per hour, the stimulation causing the release of Da.

Question 31

State the major drug categories that we covered in lecture.

Answer 31

Stimulants, analgesics, cannabinoids, hallucinogens, depressants

Question 32

How are the nucleus accumbens and dopamine related to substance abuse and addictions?

Answer 32

Axons would directly or indirectly increase the release of dopamine or norepinephrine in the nucleus accumbens (accumbens activated when imagine something pleasant).

Question 33

How do amphetamines and cocaine alter synaptic activity?

Answer 33

Amphetamines increase the release of Da, reversing the transporter, while cocaine blocks the reuptake of Da, causing it to linger in the synapse longer and bind to receptors.

Question 34

What is the drug classification for opioids and how do they alter synaptic activity?

Answer 34

Analgesics, they bind to the medulla.

Question 35

How do endorphins work and what is their purpose?

Answer 35

Endorphins inhibit an inhibitor (neurons that release GABA), thereby increasing dopamine release. They are endogenous morphines and relieve pain by acting on receptors in the brain

Question 36

Describe how cannabinoids alter synaptic activity and state what is unusual about their mechanism of action.

Answer 36

The receptors are located on the presynaptic neuron, making it different, and use retrograde transport by sending messages backwards that can bind to the receipt and tell it to slow down or stop (modulates activity going backwards).

Question 37

What did you learn about alcohol, toxicity, acetaldehyde, and enzymes? What are some of the physiological effects of alcohol- include the BBB and GABA.

Answer 37

Alcohol disrupts the lipid bilayer causing it to increase in membrane fluidity which damages the DNA as it leaks. As alcohol is metabolized, it is transformed into acetaldehyde by alcohol dehydrogenase, and then turned into acetic acid by acetaldehyde hydrogenase. It easily passes through the BBB, enhances response of GABA receptors, and inhibits potassium and sodium ions.

Question 38

What does conditioning and environmental stimuli have to do with drug addiction?

Answer 38

- Positive reinforcement (perceived effects, makes them an addicts) & negative (withdrawal avoidance, reinforcement maintains) - classical conditioning in which the body often engages in a compensatory process - incentive-sensitization where drug related stimuli are linked to the reinforcement effects of Da release

Question 39

Define tolerance and withdrawal.

Answer 39

Tolerance: can handle larger and larger amounts of the drug Withdrawal: physiological and psychological changes when the drug is not in the system

Question 40

Conditioning

Answer 40

Cravings in response to cues

Question 41

Brain reorganization

Answer 41

Other kinds of reinforcing experiences become less powerful, less able to compete with the drug