Hypothalamic neurons with activity patterns related to sympathetic nerve discharge.
Spike-triggered averaging was used to identify hypothalamic neurons with activity patterns related to inferior cardiac sympathetic nerve discharge (SND). Three neuronal types were identified in baroreceptor-innervated cats. The discharges of SR units were temporally related to SND and the R wave of the electrocardiogram. The discharges of SER units were in addition related to electroencephalogram (EEG) activity. SE unit discharges were related to SND and EEG activity but not to the R wave. Two neuronal types were identified in baroreceptor-denervated cats. The discharges of S units were temporally related to SND but not to EEG activity. The second neuronal type exhibited activity patterns similar to those for SE neurons in the baroreceptor-innervated cat. With the exception of SER neurons, all unit types could be subdivided into two groups depending on whether their discharges were followed by an increase or a decrease in SND. The discharges of SER units were followed by a decrease in SND. These data are discussed with regard to the role played by the hypothalamus in generating the basal discharges of sympathetic nerves.
D000818:Animals; D002415:Cats; D003714:Denervation; D004553:Electric Conductivity; D004558:Electric Stimulation; D004569:Electroencephalography; D005260:Female; D007031:Hypothalamus / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000502:physiology*; D011311:Pressoreceptors / Q000502:physiology; D013564:Sympathetic Nervous System / Q000502:physiology*