Effects of superior cervical ganglionectomy on body temperature and on the lipopolysaccharide-induced febrile response in rats

ROMEO, H.E., TIO, D.L., AND TAYLOR, A.N.

Ciudad de Buenos Aires

Congreso; III Iberoamerican Congress of NeuroImmunoModulation; 2009

International Society for Neuroimmunomodulation

The plausible participation of peripheral nerve fibres originating in the superior cervical sympathethic ganglia (SCG) in the modulation of body temperature as well as during the occurrence of the induced febrile response was investigated in rats. Body temperature was monitored biotelemetrically in bilateral superior cervical ganglionectomizaed (SCGx) male rats immediately after surgery to examine the accute effects during the wallerian degeneration, and chronically thereafter. The effects of LPS-induced fever were examined in long-term operated animals. SCGx attenuated the daily dark-phase temperature compared to that of the sham-operated rats during the first 2 days post surgery. Body temperatures returned to pre-surgery levels by Day-3. Ten days after surgery, a febrile response was induced by lipoplysaccharide (LPS, 25 µg/kg) immune challenge.  SCGx  significantly blunted the LPS-induced febrile response at virtually all time points during the febrile phase compared to the responses of the sham rats . The present report provides experimental evidence to support to an important and previously unidentified involvement of the cervical sympathetic innervation on body temperature and in the genesis of the LPS-induced febrile response. Our data strongly suggest that obliteration of the cervical sympathetic peripheral innervation impairs the capability to produce an induced febrile response.