Influence of nasal respiration upon normal EEG and epileptic electrographic activities in frog and turtle.

The electrographic respiratory response (ERR) was elicited by nasal air flow in the brain of the frog and turtle. It had the shape of a spindle of high voltage rhythmic activity and was propagated from the olfactory bulb predominantly into the ipsilateral hippocampal region in the frog and into the pyriform cortex in the turtle. In both animals, thalamic propagation of the ERR was also found. In both animals epileptic electrographic phenomena, were enhanced, created by local penicillin application. In the turtle epileptic electrographic manifestations were also elicited in the intact brain by simple nasal air insufflation. Diazepam (intraperitoneal administration) had no effect either on the ERR or on its triggering effect on epileptic phenomena. The possible physiological and pathophysiological interpretations of these findings are discussed.