| Abstract: | Serotonergic neurons within the dorsal raphe nucleus were driven, with similar temporal characteristics, by phasic auditory and visual stimuli in freely moving cats. Chloral hydrate (300–350 mg/kg, i.p) produced little change in the spontaneous activity of raphe neurons (−18.7%), but completely blocked the responsiveness of these units to sensory stimulation. Based on these and other data, we hypothesized that the anesthetic inactivates a general excitatory input to the dorsal raphe nucleus. |
