L5 Aplysia LTM

Question 1

which type of learning is more effective in habituation?

Answer 1

distributed (compared with massed)

Question 2

what does repeated 5HT application result in

Answer 2

mimics LTM for sensitisation
- role of 5HT can be mimicked by applying directly to SN-MN synapse
- 5 applications over 90 mins induces synaptic facilitation lasting over 24hrs
- indicates 5HT initiates both short-term and long-term changes

Question 3

how does 5HT activation cause both changes?

Answer 3

answer is protein synthesis
- transcriptional and translational blockers effective in preventing long-tern changes

Question 4

what happens with varicosities?

Answer 4

sensitised SN = increase varicosities
habituated SN = decrease varicosities

Question 5

how to trigger new synaptic proteins?

Answer 5

PKAs
essentially, if persistent activation of PKA (from 5HT) and is translocated to somatic region of SN, this will lead to modification of gene expression which generates proteins important for synapse building

Question 6

how can it theory of protein activation be proved through CREB

Answer 6

• inhibiting CREB-1 prevents long-term sensitisation
• injecting phosphorylated CREB-1 induces facilitation of MN EPSP

Question 7

what can protein synthesis relevantly be broken down to

Answer 7

it requires PKA-mediated activation of CREB –> IEGs –> LRGs –> new synaptic proteins
downstream epigenetic changes in gene expression by production of non-coding RNA, leading to DNA methylation