Effects of endotoxin and sodium salicylate on the preoptic thermosensitive neurons in tissue slices.
Effects of E. coli endotoxin and sodium salicylate (Sal) on single-unit activity of thermosensitive neurons recorded in slices of preoptic and anterior hypothalamic area (PO/AH) were studied in vitro. Perfusion of endotoxin-containing Krebs-Ringer's solution or local application of endotoxin in the immediate vicinity of recording neurons decreased and increased the firing rate of 31 of 34 warm-sensitive neurons and a cold-sensitive neuron, but had no effect on the majority of thermally insensitive neurons. In about half of warm-sensitive neurons the inhibitory response to endotoxin was preceded by a transient increase in firing rate. The pyrogen-induced decrease in firing rate in warm-sensitive neurons was reversibly blocked or attenuated by local application of Sal in a dose-dependent manner. The results are consistent with the view that pyrogen and Sal act in the PO/AH to produce fever and antipyresis, respectively, by appropriately offsetting the activity of thermosensitive neurons.
D000818:Animals; D001833:Body Temperature Regulation / Q000187:drug effects*; D004731:Endotoxins / Q000494:pharmacology*; D004926:Escherichia coli; D007032:Hypothalamus, Anterior / Q000187:drug effects; D066298:In Vitro Techniques; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D011301:Preoptic Area / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D012980:Sodium Salicylate / Q000494:pharmacology*
D004731:Endotoxins; D008070:Lipopolysaccharides; D012980:Sodium Salicylate