XXXX -activated whole-cell currents in isolated @entity2479 cells.

@entity1246 @entity2479 @entity1027 @entity4494 @entity2788 @entity2865 @entity1772 @entity2083
1. We have begun to analyze neurotransmitter-activated conductances in @entity2479 cells by measuring the response of single voltage-clamped adult @entity2083 @entity4494 cells to @entity1246 ( @entity1246 ). Here we describe 1) our method of identifying @entity4494 cells in vitro after their dissociation from @entity2788 , and 2) the response of these cells to @entity1246 in the tight-seal whole cell configuration of the patch-clamp method (cf. 41) after 1-4 days of primary cell culture. 2. Ganglion cell somata were backfilled in situ by injections of horseradish peroxidase (HRP) into the optic nerve. After dissociation of the retinas containing these cells, HRP reaction product was localized to cells that retained the size, shape, and an intracellular organelle characteristic of @entity4494 cells in situ. These features enabled us thereafter to identify @entity4494 cells in vitro without retrograde marker transport. 3. @entity1246 (3-10 microM) elicited inward currents and substantial noise increases in almost all @entity4494 cells at negative holding potentials. Reversal potential measurements in salines containing different @entity2865 concentrations indicated that @entity1246 produces a @entity2865 -selective conductance increase in @entity4494 cells. @entity1027 (10 microM) reversibly inhibited @entity4494 cell @entity1246 responses. @entity1772 (10 microM) alone elicited no responses in @entity4494 cells. 4. Noise analysis of @entity1246 -activated whole cell currents yielded elementary conductance estimates of 16 pS, with a slow time constant of 30 ms plus a faster component of 1-2 ms. No significant voltage dependence of these values was observed between -20 and -80 mV. 5. We have thus devised a means of identifying @entity4494 cells dissociated from adult retinas, identified GABAA receptors (cf. 16) on these cells, and found that the responses mediated by these receptors resemble those found in other regions of central nervous system (CNS). These results are consistent with the notion that @entity1246 may function as an inhibitory transmitter at synapses on @entity4494 cells.
