Flashcards in Test 2 terms Deck (55)
ability of synaptic function to change depending upon antecedent activity
rapid increase in amplitude of post-synaptic potentials following a train of stimuli. 2nd EPSP is bigger than the first, etc.
causes neurotransmitter release to decline during sustained synaptic activity. This depletes the pool of releasable vesicles.
increase in the amount of transmitter released from the presynaptic terminal lasting a few seconds.
increase in the amount of transmitter released from the presynaptic terminal lasting minutes (post tetanic potentiation).
formation of associations among stimuli and/or repsonses
a neutral stimulus (CS - bell) is paired with a stimulus that elicits a response (US - meat powder)
Instrumental (operant) conditioning
an organism learns to associate consequences with its own behavior. delivery of a reinforcing stimulus is contingent upon expression of a designated behavior.
reduction in a response to a stimulus that is delivered repeatedly
recovery of a habituated response due to presentation of another strong stimulus
enhancement of a response produced by presentation of a strong stimulus
motor neuron that synapses with the gill muscle, the site of which habituation appears to occur
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.
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.
persistent weakening of synapses based upon recent patterns of activity
long coiled tail and globular head which has ATPase activity. Think filament of muscle.
globular, thin filaments of muscle
rod shaped, interacts with troponin to hide actin
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
invagination of membrane into the sarcoplasmic reticulum that conducts the depolarization (EPP) which triggers the release of Ca
contraction is sustained without any relaxations
to maintain tetanic contractions in a muscle, some motor units are contracting while others relax in order to prevent muscle fatigue and failure
gamma motor neurons
neurons that innervate muscle spindles - specialized muscle fibers that sense stretch and help set muscle fiber length
alpha motor neurons
neurons that innervate the striated muscle fibers that generate the force of contraction
small units are activated by weak synaptic stimulation, large units require greater synaptic stimulation
each motor neuron innervates multiple muscle fibers in a single muscle
motor neuron pool
multiple motor neurons innervate a single muscle
basal level of gamma motor neuron activity required to enable muscle spindles to operate at all muscle lengths
golgi tendon organ
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.
pain receptor, initiates the flexion reflex
withdrawl from a painful stimulus, yet activates the contralateral limb to maintain balance
central pattern generators
local spinal cord circuits that control and coordinate complex motor behaviors, such as locomotion and swimming. involves stance and swing phases.
receives information from the vestibular system (balance, equilibrium). rapidly adjusts to stabilize posture.
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
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.
mirror motor neurons
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.
initial period of hypotonia when spinal interneurons are devoid of descending input (after a few days spinal circuits regain significant function)
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
increased muscle tone; hyperactive stretch reflexes and clonus (alternating contractions/relaxations in response to muscle stretch)
medium spiny neurons
contained within the corpus striatum (caudate and putamen), receives input from cortex, and outputs to neurons in globus pallidus and substantia nigra (pallidum)
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
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.
the difference between intended and actual movement
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
most abundant neuron in the brain, about 200,000 are in contact with 1 purkinje cell via parallel fibers
has inhibitory input synapse with purkinje cell
receive input from mossy fibers and has inhibitory output on granule cells
modifies purkinje cell dendritic output via an inhibitory synaps
made up of mossy and climbing fibers that drive activation of neurons in the deep cerebellar nuclei (DCN)
purkinje cells respond to excitatory input from the climbing fibers and granule cells and invert this signal onto the deep cerebellar nuclei
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
synapses onto granule cells, axons form parallel fibers which contact many purkinje cells
synapses with purkinje cells, is made up of granule cell fibers
conjugate eye movements that change the point of foveal fixation