title: Altered frequency responses of sympathetic nerve discharge bursts after IL-1beta and mild hypothermia.
abstract: Although interleukin-1beta (IL-1beta) administration produces nonuniform changes in the level of sympathetic nerve discharge (SND), the effect of IL-1beta on the frequency-domain relationships between discharges in different sympathetic nerves is not known. Autospectral and coherence analyses were used to determine the effect of IL-1beta and mild hypothermia (60 min after IL-1beta, colonic temperature from 38 degrees C to 36 degrees C) on the relationships between renal-interscapular brown adipose tissue (IBAT) and splenic-lumbar sympathetic nerve discharges in chloralose-anesthetized rats. The following observations were made. 1) IL-1beta did not alter renal-IBAT coherence values in the 0- to 2-Hz frequency band or at the cardiac frequency (CF). 2) Peak coherence values relating splenic-lumbar discharges at the CF were significantly increased after IL-1beta and during hypothermia. 3) Hypothermia after IL-1beta significantly reduced the coupling (0-2 Hz and CF) between renal-IBAT but not splenic-lumbar SND bursts. 4) Combining IL-1beta and mild hypothermia had a greater effect on renal-IBAT SND coherence values than did mild hypothermia alone. These data demonstrate functional plasticity in sympathetic neural circuits and suggest complex relationships between immune products and SND regulation.
authors.affiliation: Department of Anatomy and Physiology, Kansas State University, Manhattan 66506, USA. kenny@vet.ksu.edu
authors.forename: M J
authors.initials: MJ
authors.lastname: Kenney
authors.forename: F
authors.initials: F
authors.lastname: Blecha
authors.forename: R J
authors.initials: RJ
authors.lastname: Fels
authors.forename: D A
authors.initials: DA
authors.lastname: Morgan
mesh_terms: D000210:Acute-Phase Reaction / Q000503:physiopathology; D002001:Adipose Tissue, Brown / Q000502:physiology; D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D001831:Body Temperature / Q000502:physiology; D003080:Cold Temperature / Q000009:adverse effects; D003106:Colon / Q000502:physiology; D004594:Electrophysiology; D007035:Hypothermia / Q000503:physiopathology*; D007375:Interleukin-1 / Q000494:pharmacology*; D007668:Kidney / Q000187:drug effects / Q000294:innervation / Q000502:physiology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013154:Spleen / Q000187:drug effects / Q000294:innervation / Q000502:physiology; D013564:Sympathetic Nervous System / Q000502:physiology*; D013997:Time Factors
chemical_list: D007375:Interleukin-1