Lecture 19 - aplysia Flashcards
withdrawal reflex in aplysi
tactile stimulus
causes gill and siphon to withdraw
covered by parapodia
protects resp apparatus
2 types of learning in aplysia
non associative
associative
3 types of non associative
(no temporal relationship between stim and repsonse)
- habituation
- dishabituation
- sensitisation
what does tail shock do to a habituatioed aplysia
causes dishabtuation
cuz shock strong stim compared to the poking that caused the habituation
what happens if bell rings after food arrives pavlov (when is optimal learning time)
no learning with backward pairing
optimal learning = 0.5s
any longer and no association
which is better, distributed of massed training for LTM
distributed
how can aplysia show LTM
- habituation
= lasts for long time, response stays low - sensitisation
= retians a incerased response after a shock given for many days - AND for classical conditioning
= paired response still higher than unpaired after days
which of aplysia’s ganglions is unpaired
abdominal ganglion
heart rate, blood circ, resp
and controls the reflex too
chenges in AP after sensitisation
- spike broadening (inc duration of AP
- inc Ca2+
- inc NT release
- inc EPSP
hwo is serotonin involved in the relflex
serotonin released after tail shock
and if it’s sensitised, then more serotonin released
what does a biophysical analysis tell us
ionic events
how does serotonin lead to spike boradening
- blocks K+ channel
- slowed K+ efflux
- spike broadening
- increased Ca2+ influx and more NT released
how does serotonin affect cAMP
activates it
cAMP acts as second messenger and activates PKA
= spike boradening
