Direct effects of endogenous pyrogen on medullary temperature-responsive neurons in rabbits.

Publisher Website
Google Scholar
Abstract
Effects of endogenous pyrogen (EP) injected directly into the tissue near the recording site were examined on the activities of the medullary temperature-responsive(TR)neurons in rabbits anesthetized with urethane. Endogenous pyrogen prepared from rabbit''s whole blood was administered by a fine glass cannula (100-200 .mu.m in diameter) in a fluid volume of 1-4 .mu.l. The cannula was fixed to the manipulator in parallel with a microelectrode and their tips were < 0.5 mm apart. In rabbits with intact preoptic/anterior hypothalamic (PO/AH) region, 4 warm-responsive neurons of 7 were inhibited and 6 cold-responsive neurons of 7 were excited by the direct administration of the EP. In rabbits with lesions of the PO/AH, 5 warm-responsive neurons of 9 were inhibited and 6 cold-responsive neurons of 8 were facilitated by EP. Antipyretics administered locally after the EP antagonized the pyretic effect, causing a return of the discharge of TR neuron to control rate within 2.4 .+-. 1.2 (mean .+-. SD) min. Medullary TR neuron itself had the ability to respond to the EP and contributed to the development of fever.

This publication has 1 reference indexed in Scilit: