[Changes in the functional characteristics of acetylcholine activated channels of hippocampal neurons at different periods of culture].

Patch-clamp technique was used to examine activation of single acetylcholine receptor channels of hippocampal neurons of neonatal rat at different periods of culture. The conductance values showed substantial variation from patch to patch. Some of channels have the same conductance but are kinetically different. Changes in the electrophysiological behaviour of ACh-evoked channels were dependent on the duration of culture. In the earlier period (1-2 days), the 20-pS state was predominant. Isolated short openings were much more common with mean open times usually less than 2.0 ms. In the late period of culture (18-21 days), the 31-pS state was predominant. The channel openings displays either as single events (tau o1, 0.35 ms; tau o2, 1.29 ms) or as bursts of events (tau b1, 1.15 ms; tau b2, 9.6 ms) in different patches. However, 20-pS state in the late period of culture could also be observed mostly as constituting events during the long burst.