Graphs of Kainate Receptor Paper Flashcards
KA and Glutamate Trigger a Transient Increase in mIPSC Frequency
- continuous current recording for neuron before and after KA exposure (underscore)
- neuron was clamped at 0 mV in presence of TTX, SYM2206 (AMPA blocker), AP-5 (NMDA blocker)
- shows KA causes increase in frequency of mIPSC
Top graph shows interevent intervals (time between peaks) of mIPSCs were smaller when KA was introduced
There is only an apparent increase in amplitude wiht application of KA due to multiquantal events immediately after KA exposure
This shows that Ka coused an increase in mIPSC, but not when CNQX was used to block AMPA/KA and not when bicuculline and strychnine were used to block glycine and GABA
(what about KA antagonist?)
Control: voltage clamp at 0 with low-Cl- perfusate
Shows effects of:
KA
Glu (with SYM2206, AP-5, and mGluR antagonist)
AMPA (with SYM2081 to block KA receptors)
NMDA
Con A blocks KA desensitization so desensitazation of KA is responsibel for time course of mIPSP
CGP55845 blocks GABAB so its not an autoreceptor responsible for time course
ratio of frequency during last 3 seconds versus first 3 seconds
small/large = small
large/large = bigger
Thus, bigger means longer timespan
Even if I block desensitization, autoreceptor block has no effect
baclofen is an autoreceptor agonist
we see the autoreceptor does not block the effect of KA or KCl on enhanced mIPSC f (but what does this say about time course?)
Importance of KA receptor desensitization to time course of KA-induced increase in mIPSC f may indicate…
previous studies that used hippocampal slices rather than dissociated culture (allowing for rapid and complete exchange of extracellular medium) found that KA did not increase mIPSC or mEPSC f (former studies too slow to bypass KA desensitization)
