KIN 255 - modulation of stimulus evoked behaviors

changing gamma motor neuron activity

this changes muscle spindle receptor sensitivity. by changing alpha-gamma relationship alters tautness of the spindle for a weak afferent response during the same stretch

inhibiting reflex

decrease strength of effect of sensory afferent on motor neuron (gain)

facilitate the reflex

increasing gain at sensory to motor synapse

spatial summation

the aggregation of post synaptic potentials arising from multiple synapses. convergence or summation of synapses into 1 area

temporal summation

aggregation of multiple post synaptic potentials occurring close in time

nodes of ranvier

ion channels are located where in an axon

true

inhibitory neurons can be used in spatial summation to decrease the chances of an action potential t or f

inhibitory post synaptic potential

the use of inhibitory neurons is also known as what

false

the more excited an inhibitory neuron the less it will suppress the next neuron in line

t or f

true

in temporal summation the neuron will not go back to rest

t or f

glutamate

the most common excitatory neurotransmitter

GABA

the most common inhibitory neurotransmitter

glycine

a main inhibitory NT in the spinal cord

acetylcholine

NT for muscle contraction and cholinergic system

dopamine

dopaminergic system NT

serotonin

serotonergic system NT

norepinephrine

noradrenergic system NT

acetylcholine, dopamine, serotonin and norepinephrine

which NT flow throughout the brain

receptors

NT bind to specific sites on special complex proteins called

ionotropic

ion channels are directly connected to receptor and fast acting

glutamate and GABA

ionotropic receptors use what NT

metabotropic

slow acting and NT binds to it, not a receptor. Uses a 2nd messenger and signaling cascade

brain plasticity

ionotropic receptors open if bound to a NT and the internal voltage is in a certain state

synaptic modulation

a change in relationship b/w pre-synaptic action potential and the post synaptic potential

pre-synaptic modulation

change in amount of NT released by the pre-synaptic neuron

post-synaptic modulation

change driven by the post-synaptic neuron's response o the NT

pre-synaptic facilitation

this pre synaptic modulation includes increasing the amount of NT released

pre-synaptic inhibition

this pre synaptic modulation includes decreasing the amount of NT released

chlorine ion channels

during pre/post-synaptic inhibition what ion channels open

unlikely to open

due to the Cl- channels, Ca2+ channels will be

true

pre-synaptic inhibition includes less glutamate released from the pre-synaptic terminal

t or f

small influx

if less ion channels open in the post synap. terminal then there is a ________ of Na+

false

is the EPSP is small then it will be likely to trigger an action potential

t or f

inhibitory neuron

the __________ suppresses the excitatory effect of the presynaptic neuron

faciliatory neuron

what opens sodium channels to help make the internal environment more positive

likely to open

in a more positive environment, what happens to calcium channels

true

a larger EPSP would be more likely to trigger an AP

t or f

presynaptic neuron

a faciliatory neuron enhances the excitatory effect of the __________ on the post synp. neuron

charges cancel out

the Cl- ions will summate with the Na+ ions in the post-synap. terminal causing what

small , less likely

if the charges cancel out in the postsynaptic neuron, the EPSP will be ____ making it ______ to make an AP

true

inhibitory neuron suppresses post. synap. neurons response to presynaptic neuron, meaning nothing has changed in the presynaptic neuron compared to baseline

t or f

augments

faciliatory neuron _______ the post synaptic neurons response to the presynaptic neuron

input

what determines the activity of the inhibitory/faciliatory neurons comes from two main sources

sensory inputs/ centripetal

inputs from the primary afferent or interneurons mediated by afferent inputs (same level as spinal cord)

central/descending/centrifugal

inputs arise from 'higher' centres (brain stem, cerebellum, cortex)

control reflex

measuring a muscle that moves alone/by itself is known

conditioned reflex

measuring a muscle where another muscle influences inhibitory influence over it

homonymous

a control reflex will take what type of pathway?

heteronymous

a conditioned reflex will take what type of pathway?

postsynaptic centripetal

the soleus and the tibialis anterior working together (agonist and antagonist) are examples of what type of modulation

presynaptic centripetal

the soleus and the quadriceps working together (agonist and synergist) are examples of what type of modulation

corticospinal tract

this centrifugal modification adjust reflex pathways to reduce conflict with voluntary movements

vestibulospinal

this centrifugal modification coordinate spinal reflexes with vestibular mediated responses (usually for balance)

reticulospinal

this centrifugal modification adjust reflex pathways during locomotion

rubrospinal

this centrifugal modification modulates flexor reflex activity (withdrawal reflex)

motoneurons, interneurons in grey matter

what can descending tracts influence in centrifugal modulation

false

centripetal and centrifugal mechanisms cannot work together for skilled behaviours

t or f

phase dependent modulation

change (ex: inhibition, facilitation, complete reversal) of response evoked a specific stimulus depending on the phase of a movement

increase

relaxing the soleus during stance phase will ________ the chances of falling

decrease

relaxing the soleus during swing phase of gait cycle willl _________ chances of stumbling and falling

nociception

neural process of detecting and processing noxious stimuli

pain

unpleasant sensory and emotional experience associated with actual or potential tissue damage, and how we perceive it

nociceptive pain

pain arising from damage or potential damage to tissue (activating nociceptors)

neuropathic pain

non-nociceptive pain that arises due to damage or insult to nervous system that convey nociceptive information (i.e. pinched nerve)

other pain

pain unrelated to nociceptor or related nervous system activity

centripetal modulation

rubbing the skin after hitting your limb is an example of what kind of modulation for pain perception

decrease

when sensation from the mechanoreceptors are activated during activation of nociceptors, info from mechano receptor and nociceptors meet and interact on a interneuron. will pain increase or decrease

nociceptive inputs

descending tracts can influence _______ at many sites

fast acting descending pathways

neuromodulators or hormone are used to suppress synaptic activity in pain pathways

adrenergic system

the use of adrenaline, norepinephrine or serotonin on a descending pathways that directly inhibits 2nd order neuron

enkephalin

Inhibitory NT activated by inhibitory neuron which was activated by serotonin

inhibit activity at synapse

how does enkephalin work