Histamine does not play an essential role in electrocortical activation during waking behavior.
Intraperitoneal injection of alpha-fluoromethylhistidine (alpha-FMH; 200 mg/kg), a specific inhibitor of histidine decarboxylase produced a severe depletion of neocortical and hippocampal histamine 3 h later as determined by a radioenzymatic assay. This treatment had no obvious effect on either low voltage fast activity (LVFA) in the neocortex or on rhythmical slow activity (RSA) in the hippocampus during an 8 h recording period during the rats' light cycle. Scopolamine-sensitive LVFA, scopolamine-resistant LVFA and scopolamine-resistant hippocampal RSA all appeared unaffected. This suggests that any contribution histamine makes to electrocortical activation is probably indirect, acting via other transmitter systems.
Servos
P
P
Department of Psychology, University of Western Ontario, London, Canada.
Barke
K E
KE
Hough
L B
LB
Vanderwolf
C H
CH
D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism / Q000502:physiology*; D004567:Electrodes, Implanted; D004569:Electroencephalography / Q000187:drug effects; D004594:Electrophysiology; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology; D006632:Histamine / Q000378:metabolism / Q000502:physiology*; D006640:Histidine Decarboxylase / Q000037:antagonists & inhibitors; D008124:Locomotion / Q000187:drug effects; D008297:Male; D008762:Methylhistidines / Q000494:pharmacology; D051381:Rats; D012601:Scopolamine / Q000494:pharmacology; D014851:Wakefulness / Q000502:physiology*
D008762:Methylhistidines; C028309:alpha-fluoromethylhistidine; D006632:Histamine; D012601:Scopolamine; D006640:Histidine Decarboxylase