Synchronization of epileptiform bursts induced by 4-aminopyridine in the in vitro hippocampal slice preparation.
Neuronal activity in hippocampal slices can be synchronized by drugs which either block synaptic inhibition (e.g. bicuculline methiodide) or do not (e.g. 4-aminopyridine). Here we compare these two drugs to assess the role of inhibition on the recruitment of neurones into synchronous epileptiform bursts. With 4-aminopyridine we recorded an acceleration of neuronal activity, and in most cells a slow depolarization (mean 6.8 mV), during the ca. 100 ms preceding the population burst. With bicuculline these changes occurred ca. 10 ms before the population bursts, and depolarizations reached a mean of 2.5 mV. We propose that bicuculline-sensitive synaptic inhibition retards the recruitment of neurones into epileptiform synchronous bursts.
Ives
A E
AE
Department of Physiology and Biophysics, St. Mary's Hospital Medical School, Imperial College, University of London, U.K.
Jefferys
J G
JG
D015761:4-Aminopyridine / Q000494:pharmacology*; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D004827:Epilepsy / Q000503:physiopathology*; D006624:Hippocampus / Q000187:drug effects / Q000503:physiopathology*; D066298:In Vitro Techniques; D008297:Male; D009431:Neural Conduction / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D011999:Recruitment, Neurophysiological / Q000187:drug effects*
D015761:4-Aminopyridine; D001640:Bicuculline