Electrophysiological evidence for the modular organization of the reticular formation: sympathetic controlling circuits.

Cross-correlation analysis revealed that the discharges of cat medullary reticular neurons located in the recording field of a single microelectrode were synchronized on a time scale of a few ms. The incidence of short time scale interactions was significantly greater when both members of a neuronal pair had activity temporally related to postganglionic inferior cardiac sympathetic nerve discharge than when only one member had sympathetic nerve-related activity. The data support the view that the reticular formation is organized into functionally distinct modules that are potentially interactive.