Cobalt microinjections into the infralimbic cortex of the anesthetized rat suppresses circulatory and respiratory reactions to the microelectrostimulation of the lateral orbital cortex

Abstract

The central autonomous network that controls visceral systems, including circulatory and respiratory systems, includes the visceromotor infralimbic cortex (IL), which is one of the areas of the prefrontal cortex and is located on the medial surface of the large hemispheres. At the same time, there is evidence that areas of the prefrontal cortex located on the orbitofrontal surface, including the lateral orbital cortex (LO), can participate in the control of autonomous functions. The purpose of this work was to experimentally test the hypothesis according to which the participation of LO in the control of respiratory and circulatory functions is realized through IL. To this end, in acute experiments on laboratory rats anesthetized with urethane, the effect of microinjections of cobalt chloride solution (CoCl2) in IL on the reactions of circulatory and respiratory systems caused by microelectrostimulation of LO was investigated. It is known that Co2+ ions are non-specific blockers of synaptic transmission, therefore microinjections of CoCl2 solutions lead to disruption of conduction in the structures of the central nervous system. In the first, control series of experiments, micro-electrical stimulation of LO caused specific responses of the circulatory and respiratory systems, which were consistently reproduced throughout the experiment. In the second, experimental series, the introduction of CoCl2 solution into IL suppressed responses to micro-electrical stimulation of LO, and this effect turned out to be reversible. The obtained results confirmed the hypothesis put forward about the possible participation of IL in the implementation of autonomous LO functions. The elucidation of the mechanisms that ensure the interaction of LO and IL in the context of autonomous control should be the subject of further experimental research.