Test 2 terms

Question 1

plasticity

Answer 1

ability of synaptic function to change depending upon antecedent activity

Question 2

facilitation

Answer 2

rapid increase in amplitude of post-synaptic potentials following a train of stimuli. 2nd EPSP is bigger than the first, etc.

Question 3

depression

Answer 3

causes neurotransmitter release to decline during sustained synaptic activity. This depletes the pool of releasable vesicles.

Question 4

augmentation

Answer 4

increase in the amount of transmitter released from the presynaptic terminal lasting a few seconds.

Question 5

potentiation

Answer 5

increase in the amount of transmitter released from the presynaptic terminal lasting minutes (post tetanic potentiation).

Question 6

associative learning

Answer 6

formation of associations among stimuli and/or repsonses

Question 7

classical conditioning

Answer 7

a neutral stimulus (CS - bell) is paired with a stimulus that elicits a response (US - meat powder)

Question 8

Instrumental (operant) conditioning

Answer 8

an organism learns to associate consequences with its own behavior. delivery of a reinforcing stimulus is contingent upon expression of a designated behavior.

Question 9

habituation

Answer 9

reduction in a response to a stimulus that is delivered repeatedly

Question 10

dishabituation

Answer 10

recovery of a habituated response due to presentation of another strong stimulus

Question 11

sensitization

Answer 11

enhancement of a response produced by presentation of a strong stimulus

Question 12

L7

Answer 12

motor neuron that synapses with the gill muscle, the site of which habituation appears to occur

Question 13

L29

Answer 13

interneuron that releases serotonin in response to the head shock. this activates GPCRs that are linked to CAMP production, which activates PKA which phosphorylates and CLOSES K channels. closing K channels decreases K conductance and prolongs the AP and allows more Ca inside.

Question 14

Long-term potentiation

Answer 14

long lasting enhancement of the strength of stimulated synapses. LTP is input specific, the input only affects the pathway it is associated with. membrane potential of postsynaptic cell determines if LTP will occur. AMPA and NMDA receptors.

Question 15

long-term depression

Answer 15

persistent weakening of synapses based upon recent patterns of activity

Question 16

myosin

Answer 16

long coiled tail and globular head which has ATPase activity. Think filament of muscle.

Question 17

actin

Answer 17

globular, thin filaments of muscle

Question 18

tropomyosin

Answer 18

rod shaped, interacts with troponin to hide actin

Question 19

troponin

Answer 19

protein complex that associates with tropomyosin to form a barrier to formation of cross-bridges between actin and myosin. when Ca binds the tropomyosin-troponin complex exposes myosin

Question 20

t tubules

Answer 20

invagination of membrane into the sarcoplasmic reticulum that conducts the depolarization (EPP) which triggers the release of Ca

Question 21

tetanus

Answer 21

contraction is sustained without any relaxations

Question 22

asynchronous recruitment

Answer 22

to maintain tetanic contractions in a muscle, some motor units are contracting while others relax in order to prevent muscle fatigue and failure

Question 23

gamma motor neurons

Answer 23

neurons that innervate muscle spindles - specialized muscle fibers that sense stretch and help set muscle fiber length

Question 24

alpha motor neurons

Answer 24

neurons that innervate the striated muscle fibers that generate the force of contraction

Question 25

size principle

Answer 25

small units are activated by weak synaptic stimulation, large units require greater synaptic stimulation

Question 26

motor unit

Answer 26

each motor neuron innervates multiple muscle fibers in a single muscle

Question 27

motor neuron pool

Answer 27

multiple motor neurons innervate a single muscle

Question 28

gamma bias

Answer 28

basal level of gamma motor neuron activity required to enable muscle spindles to operate at all muscle lengths

Question 29

golgi tendon organ

Answer 29

these are in series with extrafusal muscle fibers, are innervated by group 1b sensory afferents, relatively insensitive to passive stretch but are very sensitive to muscle contraction. this regulates muscle tension with negative feedback pathway.

Question 30

nociceptor

Answer 30

pain receptor, initiates the flexion reflex

Question 31

flexion reflex

Answer 31

withdrawl from a painful stimulus, yet activates the contralateral limb to maintain balance

Question 32

central pattern generators

Answer 32

local spinal cord circuits that control and coordinate complex motor behaviors, such as locomotion and swimming. involves stance and swing phases.

Question 33

vestibular complex

Answer 33

receives information from the vestibular system (balance, equilibrium). rapidly adjusts to stabilize posture.

Question 34

reticular formation

Answer 34

cardiovascular & respiratory control, sensory motor reflexes, eye movements, sleep, arousal, coordination of limb and trunk movements. initiates adjustments to stabilize posture during movement. is modulatory and premotor

Question 35

homunculus model

Answer 35

shows what a man's body would look like if each part grew in proportion to the area of the cortex of the brain concerned with its movement.

Question 36

mirror motor neurons

Answer 36

distinctive class of neurons that discharge both when a monkey executes a motor act and when it observes another individual performing the same or similar motor act.

Question 37

spinal shock

Answer 37

initial period of hypotonia when spinal interneurons are devoid of descending input (after a few days spinal circuits regain significant function)

Question 38

Babinski sign

Answer 38

when dragging a pointy object along the bottom of the foot the toes extend and fan out. indicates damage to corticospinal pathway, and is a potential sign of MS

Question 39

spasticity

Answer 39

increased muscle tone; hyperactive stretch reflexes and clonus (alternating contractions/relaxations in response to muscle stretch)

Question 40

medium spiny neurons

Answer 40

contained within the corpus striatum (caudate and putamen), receives input from cortex, and outputs to neurons in globus pallidus and substantia nigra (pallidum)

Question 41

Parkinson's disease

Answer 41

disease caused by loss of dopaminergic neurons in the substantia nigra. characterized by tremor, slowed motion, rigid muscles, impaired posture and balance, dementia, etc. treated with L-dopa and possibly stem cell therapy

Question 42

Huntington's disease

Answer 42

hereditary, progressive disease that is always fatal. appearance characterized by hyperkinesia and chorea, abnormal movements, dementia, personality disorder. caused by genetic mutation int he gene that produces huntingtin which leads to neuronal cell death. can only treat the symptoms.

Question 43

motor error

Answer 43

the difference between intended and actual movement

Question 44

Purkinje cells

Answer 44

the only output cells of the cerebellar cortex, all of which are inhibitory. receives input from parallel (from as many as 200,000 granule cells) and climbing fibers

Question 45

granule cell

Answer 45

most abundant neuron in the brain, about 200,000 are in contact with 1 purkinje cell via parallel fibers

Question 46

basket cell

Answer 46

has inhibitory input synapse with purkinje cell

Question 47

golgi cell

Answer 47

receive input from mossy fibers and has inhibitory output on granule cells

Question 48

stellate cell

Answer 48

modifies purkinje cell dendritic output via an inhibitory synaps

Question 49

excitatory loop

Answer 49

made up of mossy and climbing fibers that drive activation of neurons in the deep cerebellar nuclei (DCN)

Question 50

inhibitory loop

Answer 50

purkinje cells respond to excitatory input from the climbing fibers and granule cells and invert this signal onto the deep cerebellar nuclei

Question 51

climbing fiber

Answer 51

provides input to the purkinje cell, 1:1 ration, may have 1000 synapses with each cell. AP in climbing fiber gives strong EPSP in purkinje cell

Question 52

mossy fiber

Answer 52

synapses onto granule cells, axons form parallel fibers which contact many purkinje cells

Question 53

parallel fiber

Answer 53

synapses with purkinje cells, is made up of granule cell fibers

Question 54

saccades

Answer 54

conjugate eye movements that change the point of foveal fixation

Question 55

GABAergic

Answer 55

inhibitory synapses that open Cl channels, how outputs from basal ganglia performs inhibition