Lecture 11 Flashcards
synaptic plasticity
the ability of synapses to strengthen OR weaken over time in response to changes in activity
learning: (2 definitions)
- acquisition of new information or knowledge
2. a change in behavior as a result of experience
memory: (2 definitions)
- retention of learned information
2. ability to store and recall learned experiences
short-term synaptic facilitation: when two or more action potentials __ and cause prolonged, elevated __ and an increase in __
arrive very close in time; Ca in the presynaptic terminal; the next action potential’s strength
short-term synaptic facilitation: as we increase the interval between two action potentials, the amount of facilitation __
goes down
(short-term synaptic facilitation) the facilitation effect is only about __ (nothing else matters)
presynaptic calcium
two types of short-term synaptic plasticity:
facilitation (strengthening connection) and depression (weakening connection)
short-term synaptic depression: when two or more action potentials happen closely in time, there is a decrease in __ due to the progressive __
synaptic strength; depletion of the pool of synaptic vesicles/using up all the neurotransmitters
tetanus
sustained synaptic activity
the level of synaptic depression is proportional to the __
amount of transmitter released from the presynapse (the more we release, the more we depress)
(synaptic depression) what if we reduced the amount of calcium in the environment?
it would take longer for the neurotransmitter pools to be emptied, therefore we would delay the depression effect
what type of relationship exists between amount of facilitation and interval between stimuli?
inverse root (L-shaped curve)
what type of relationship exists between amount of depression and relative amount of transmitter released?
proportional (linear)
procedural learning and memory: __ and __. performed without __. require __ but not easily __
skills and behaviors
performed without conscious recall
require practice
not easily forgotten
declarative learning and memory: __ and __. __ recalled. easy __
facts and events. consciously recalled. “easy come easy go”
2 types of implicit/procedural learning and memory
associative and non-associative
associative learning is a __ relationship, association is learned between __ or __
predictive; two stimuli or stimuli and a behavior
classical conditioning: __ response is expressed in response to a __
innate; neutral stimulus
which type of implicit/procedural learning does this describe? “learning to predict future events based on experience (negative or positive)”
associative
what type of conditioning, and learning, is the example of Pavlov’s dog
classical conditioning; implicit/procedural learning
what type of conditioning, and learning is the example of Skinner’s rats
operant conditioning; implicit/prodecural learning
non-associative learning produces a change in the __ due to repeated exposure to the __
strength of response to a single stimulus; same stimulus
an example of non-associative learning would be
aplysia gill/siphon withdrawal reflex
non-associative learning: the response changes with __
experience
classical conditioning pop culture example
the office: Dwight and the altoids!
Aplysia have a simple __ and __ neurons
nervous system; large, identifiable neurons
what is the gill-withdrawal reflex of Aplysia?
if you touch the siphon, the animal retracts the entire thing (siphones, gills, etc.)
what is the decreased response of Aplysia after repeated probing of the siphon due to?
habituation, NOT anything like muscle fatigue
if you pair a noxious stimulus (__) with gentle touch of siphon you get __, which is an example of __
tail shock; an enhance gill withdrawal response; sensitization
sensitization allow an animal to __
generalize the response to an aversive stimuli, so that they respond the same way to other stimuli (generalize the response to one stimuli, to others)
with repeated pairing of the siphon/tail thing, you can make the generalized response __
long-term
gill withdrawal habituation causes a weakening of the __ synapses, (__)
sensory neuron to motor neuron; synaptic depression
(synaptic depression/habituation) if we stimulate the __, we get an EPSP on the __. this EPSP gets smaller and smaller as stimulation continues, it becomes __ and __
sensory neuron; motor neuron; habituated; runs out of neurotransmitter to release
(habituation) the action potential from the sensory neuron never changes strength (T/F)
TRUE! its the EPSP in the motor neuron that diminishes
(gill withdrawal sensitization) __ from secondary pathway (__) talks back to sensory neuron in siphon to __ the response
modulatory interneuron; tail shock; enhance
gill withdrawal habituation is an example of synaptic __
gill withdrawal sensitization is an example of synaptic __
depression; facilitation
modulatory interneuron releases __ which enhances neurotransmitter release from the __, which leads to an increase in excitation of the __ and therefore an enhanced response
serotonin; siphon sensory neuron; motor neuron
shock activates __ release from __
serotonin; modulatory interneuron
serotonin activates __ in the axonal terminals of the __, which activate __ which causes an increase in __ which activates __ - an enzyme that affects protein expression… all leading to more neurotransmitter (__) release
G-protein coupled receptors; sensory neuron; Adenalyl cyclase; cyclic AMP; protein kinase A; glutamate
Protein kinase A __ potassium channels - makes them work better but reduces __ (reduces the probability that __)
so we’re essentially stopping the __ phase and prolonging the __, allowing more __ to come in, allowing more release of the neurotransmitter
phosphorylates; voltage sensitivity; potassium channels will open during a presynaptic action potential repolarization phase (when K channels open); presynaptic action potential; calcium
what does the phosphorylation of K channels by protein kinase A cause? (3)
longer-lasting action potentials, more Ca influx, and more neurotransmitter (glutamate) release
short-term memory cascade:
long-term memory cascade:
G-protein activation leads to protein kinase A causing a change in ion conductance, causing more calcium influx and more glutamate release
second messenger cascade involving protein kinase A and CREB and more transcription (both caused by serotonin)
short-term memory is post-translational __
long-term memory is changes in __ and __
modification of existing proteins; gene expression and synthesis of new proteins
the hippocampus is essential for __
forming new memories
episodic memory
the collection of past personal experiences that occurred at particular time and place
patient H.M. had severe __, they removed significant portions of the brain including __ and he could no longer __
epilepsy; hippocampus; form new episodic memories
example of episodic memory
spatial navigation
what does the hippocampus look like?
a seahorse!
spatial learning and memory in rats depends on the __
hippocampus
Morris water maze: __
normal rats: __
rats with no hippocampus: __
hidden platform in pool
1st time takes a while to find it, soon (after 10 trials) learns where it is
never learn where it is (first trial and 10th trial look the same)
hippocampal place cells experiment found that hippocampal cell increased their activity whenever a rat _-
was in a certain region of an arena
hippocampal place cells: each cell’s “firing field” =
region of arena where that cell is active
hippocampal cells are ___-tuned
spatially
is the hippocampus the first region of the brain where we have observed “place” neurons?
yes
hippocampal place cells: are the shape and size of firing field fairly consistent?
no, they can vary quite a bit from one cell to another
during high frequency stimulation, Ca influx leads to the modification of __
AMPA receptors
Ca enters the postsynaptic dendrite through __ receptors and activates long-lasting changes in __ receptors
NMDA; AMPA
more AMPA receptors increases the permeability to __, which means __
Na; larger EPSPs
T/F: long-term potentiation is NMDA dependent?
true, because we need the calcium influx!
remember: gNa =
permeability to Na
long-term depression: __ influx of Ca causes this by inducing __ of AMPA receptors from the synapse. __ AMPA receptors = __ EPSPs
small; removal; fewer; smaller, weaker
