PHAR 562 Lecture Notes - Lecture 6: Na-K-Cl Cotransporter, Gephyrin, Glutamic Acid
12 Feb 2020
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Document Summary
Just like glutamatergic synapses, gabaergic synapses are also plastic. Ca2+ influx phosphorylation events ampar recruitment to synaptic membrane increased synaptic strength. In gabaa-rs: for different periods in development, switch between being an excitatory & inhibitory system. Gabaergic system = the first excitatory system in the nervous system (even before glutamatergic system kicks in) Plasticity mechanisms of gabaergic system are different from those of glutamatergic system. Different mechanisms for strengthening gabaergic transmission, in addition to pharmacological means: phosphorylation, gephyrin, & receptor trafficking. Gephyrin: postsynaptic scaffolding protein, labels a mature gabaergic synapse (i. e. analogous to psd-95 in glutamatergic synapses: cl- equilibrium potential & transporters, nkcc1 & kcc2. During development, see changes in [cl-] across cells. Nkcc1: pumps chloride into the cell, so when gabaa-rs open cl- ions leave the cell depolarization i. e. gaba is excitatotory. Kcc2: removes chloride out of the cell, so when gabaa-rs open cl- influx hyperpolarization i. e. gaba is inhibitory.
