Aplysia: Sensitization and Habituation; Classical Conditioning; Consolidation Flashcards
Sensitization and habituation are examples of what kind of learing?
Non-Associative Learning
Classical Conditioning is an example of what kind of learning?
Associative learning
Why do we use model systems?
All animals learn
NS physiology is similar across species
simple systems easier to reveal cellular processes
Why Aplysia?
~15,000 neurons organized into ganglia
Identified cell number, location, and connectivity
What happens when the siphon skin is stimulated?
The gill withdraw reflex happens
What does the abdominal ganglion control?
Siphon and gills
What are the two pathways for the gill withdraw reflex?
Direct: SN -> MN -> muscle
Indirect: SN -> Ex. Int. -> MN -> muscle
Why have two pathways?
Redundancies allow for back ups incase of injury
allows for modulation of the circuit
How many SN are excited on siphon skin stimulation?
44 Glut
What is habituation?
If the stimulus is non-threatening the animal will ignore the stimulus after a while
Which neuron shows decrease in EPSP?
the motor neuron
What is iontophoresis?
delievering small amounts of a chemical(NT) directly to a single cell
What is Quantal Analysis?
The measurement of how many vessicles are released from the pre-synaptic neuron
What causes the habitual learning?
A change in the release of Glut from the pre-synaptic cell( reduced)
What causes less NT to be released?
Closing of Ca2+ channels
What does Ca2+ do in a pre-synaptic neuron?
It allows vesicles to fuse to the membrane and release NT
What is an example of Sensitization in Aplysia?
habituation an animal to siphon stimulation then paring it with stimulation of the tail
What is an Axo-axonic aynpase?
when an axon creates a synapse with another axon terminal
Where does the tail pathway innervate the gill withdraw reflex pathway?
It creates axo-axonic synapses with the Ex. Int. and the MN
Axo-axonic synapses cause a greater response in the MN via?
metabotropic biochemical cascades
What is the outcome of these biochemical cascades?
Phosphorylation of K+ channels
Opening of Ca2+ channels
Mobilization of vesicles
What does the closing of K+ channels result in?
Extended depolarization, more NT released
What happens when the FI(Facilitative Interneuron) is stimulated?
Increase levels of cAMP
