Polygraphic study of anterior hypothalamic-preoptic neuron thermosensitivity during sleep.
Thermal responsiveness of anterior hypothalamic-preoptic (AH-PO) neurons was studied in unanesthetized sleeping cats carrying chronically implanted electrodes and thermistors for recording EEG, EMG and AH-PO temperature. Activity of AH-PO neurons was recorded using tungsten microelectrodes during atraumatic stereotaxic head restraint in a sound-attenuated chamber at 22-25 degrees C. Direct cooling or warning of the AH-PO region was accomplished with bilaterally positioned water-perfused thermodes. 110 thermosensitive neurons (77% cold-sensitive and 23% warm-sensitive) were sampled during wakefulness and synchronized sleep. In contrast, the changes in spontaneous firing rate shown by AH-PO neurons during desynchronized sleep were often associated with a strong depression or outright suppression of their responsiveness to AH-PO thermal stimulation.
Parmeggiani
P L
PL
Azzaroni
A
A
Cevolani
D
D
Ferrari
G
G
D000818:Animals; D002415:Cats; D007032:Hypothalamus, Anterior / Q000166:cytology / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D010812:Physical Stimulation; D011301:Preoptic Area / Q000166:cytology / Q000502:physiology*; D012890:Sleep / Q000502:physiology*; D013696:Temperature; D013697:Thermosensing / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology