Chapter 1

Question 1

ion channels…

Answer 1

passive transport, selectively permeable, can be gated, Na+, K+, Ca2+, Cl-

Question 2

ion pumps…

Answer 2

active transport, require ATP, Na+/K+, Ca2+

Question 3

resting membrane potential

Answer 3

-70mV

Question 4

hyperpolarization

Answer 4

change in membrane potential, IPSPs

Question 5

depolarization

Answer 5

change in membrane potential, EPSPs

Question 6

action potential

Answer 6

rapid depolarization and depolarization, occurs at ~55mV

Question 7

Action potential events (5)

Answer 7

1. at threshold, voltage gated Na+ channels open and Na+ flows into cell
2. more Na+ flows into cell increasing depolarization
3. voltage gated K+ channels open, K+ flows OUT of cell
4. Na+ channels close, K+ channels still open. during hyper polarization, another AP cannot be generated
5. K+ channels close when membrane is hyper polarized, membrane potential returns to steady state

Question 8

absolute refractory period

Answer 8

period following the firing of an action potential when it cannot be stimulated no matter how great the stimulus is

Question 9

relative refractory period

Answer 9

period shortly after the firing of a nerve finer when partial depolarization has occurred and a greater than normal stimulus can stimulate a second response

Question 10

hodgkin-huxley model

Answer 10

mathematical model of action potentials

Question 11

electrotonic conduction

Answer 11

fast, passive, short distances

Question 12

self-propogating conduction

Answer 12

action potential ripples down axon, keeps regenerating new signals, slow, long distances

Question 13

saltatory conduction

Answer 13

relatively fast, self-regenerating, long distances, myelinated sections are insulated (where electronic conduction occurs)

Question 14

speed of propogation

Answer 14

depends on axon diameter, myelination, temp, etc.

slow as <1m/s, fast as >120m/s

Question 15

neural coding (AP signals)

Answer 15

neural coding depends on rate, duration and timing

Question 16

synaptic vesicle cycle

Answer 16

Ca+ entering the pre-synaptic cell causes vesicle to fuse with the membrane, causing ion channels to open allowing NT to release and cross synaptic cleft

Question 17

inhibitory PSPs (4)

Answer 17

1. prevent runaway firing of APs
2. help control the energy consumption of the brain
3. contribute to important oscillatory patterns of neural activity
4. provide basis for negation as a computational primitive

Question 18

7 major NTs

Answer 18

glutamate, GABA, acetylcholine, dopamine, serotonin, noradrenaline (norepinephrine), histamine

Question 19

5 biochemical NT classifications

Answer 19

amino acids, monoamines, peptides, gases, other

Question 20

Neurotransmitter characteristics

Answer 20

synthesized by & localized within presynaptic neurons, stored in terminal bouton, released by presynaptic neurons during APs, postsynaptic neutrons contain receptors specific to it, a mechanism exists to remove it after release

Question 21

3 ways of NT reuptake

Answer 21

active reuptake : pumped back into presynaptic neuron
enzymatic breakdown
diffusion out though extracellular membrane

Question 22

metabotropic receptor

Answer 22

work through 2nd messenger cascade

ei. G-protein coupled receptors

Question 23

gap junction

Answer 23

direct electrical and chemical conduction, fast, low plasticity, no amplification

Question 24

post synaptic potential

Answer 24

travels from synapse to axon hillock by electrochemical conduction (all PSPs converge at the axon hillock)

Question 25

PSPs at the trigger zone

Answer 25

strength depends on strength of PSP at synapse, time course of the PSP, distance to the synapse, time since the AP

Question 26

summation of PSPs

Answer 26

EPSPs add to the membrane potential, IPSPs subtract from the membrane potential. trigger zone starts at the resting potential (-70mv), AP fires if sum exceeds threshold

Question 27

spatial summation

Answer 27

PSPs from different synapses (locations) sum together

Question 28

temporal summation

Answer 28

PSPs from same synapse (different points in time) sum together

Question 29

synaptic integration as computation

Answer 29

at each point in time, neutron sums all of its inputs which are then graded, output is all or none depending if threshold is exceeded

Question 30

church-turing thesis

Answer 30

every effectively calculable function is a computable function

Question 31

computational universality

Answer 31

all turing complete systems are computationally equivalent

Question 32

Alan Turing (1912-1954)

Answer 32

turing test, universal turin machine, helped break the german enigma code in WWII

Question 33

reflex circuit

Answer 33

inhibitory interneuron: out the ventral root, along the axon to the muscle, causing contraction sensory input on knee, down the axon into dorsal root

Question 34

artificial neural network (ANN)

Answer 34

understanding brain function by allowing stimulation & prediction. artificial intelligence: program to control computer, robot or machine

Question 35

Green fluorescent protein

Answer 35

inserted into DNA to target protein, when protein is expressed, so is the fluorescence

Question 36

brainbow

Answer 36

a single rainbow transgene expresses red, cyan, or yellow. multiple rainbow transgress can express more colours