Histamine enhances synaptic transmission in hippocampal slices from hibernating and warm-acclimated Turkish hamsters.
The effects of histamine on synaptic transmission were studied at 37 degrees C and 22 degrees C with extracellular recordings of stimulus-induced population action potentials in area CA1 of hippocampal slices prepared from hibernating (HTH) and warm-acclimated Turkish hamsters (WTH) and rats. In rat slices, application of 50 microM histamine had no effects on population spikes and field excitatory postsynaptic potentials (EPSPs). In HTH as well as WTH slices, 50 microM histamine generally increased the population spike amplitude. The slope of the field EPSP was unchanged. At 37 degrees C, the sensitivity for histamine was significantly higher in HTH slices than in WTH slices. At 22 degrees C, the effects of histamine were less pronounced in HTH as well as WTH slices. Hibernation-related improvement of sensitivity for histamine is interpreted as supporting hippocampal function during arousal from hibernation.
Nikmanesh
F G
FG
Zentrum Physiologie and Pathophysiologie, Universität zu Köln, Germany.
Spangenberger
H
H
Igelmund
P
P
D000064:Acclimatization / Q000187:drug effects; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D006224:Cricetinae; D004594:Electrophysiology; D006605:Hibernation / Q000502:physiology*; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D006632:Histamine / Q000494:pharmacology*; D006358:Hot Temperature; D009924:Organ Culture Techniques; D051381:Rats; D017208:Rats, Wistar; D009435:Synaptic Transmission / Q000187:drug effects*
D006632:Histamine