An analysis of the electrical burst phenomenon in some rhinencephalic structures of the dog and monkey

Abstract

Electrical bursts of approximately 20 to 40 c/sec. were observed in some rhinencephalic areas including the olfactory bulb, olfactory stria, pyriform and prepyriform cortex, and the medial amygdala of the dog and the monkey with chronically implanted electrodes. The amplitude of the electrical bursts depended upon the degree of gross behavioral arousal and respiratory stimulation. The more aroused and excited the animal the greater was the amplitude and frequency of the electrical activity. These bursts were of a spindling character and appeared to be due to the flow of air through the ipsilateral nostril. They could be abolished by occlusion of the ipsilateral nostril or by spraying the nasal mucosa with a local anesthetic solution.Various drugs that modified the state of arousal and respiration modified the electrical bursts; d-Amphetamine and trans-[pi]-oxocamphor markedly increased the electrical burst activity while morphine, chlorpromazine, and alpha-chloralose depressed this activity. Most but not all of the effects observed were related to the degree of respiratory stimulation or depression.