EFFECT OF CORTICAL STIMULATION ON RESPIRATORY RATE

Abstract

There are 2 cortical areas, electrical stimulation of which will retard respiration in dog and cat (a) a small area of the cingu-late gyrus anterior and inferior to the genu of the corpus callosum; (b) a larger area which includes the anterior portion of anterior sylvian and ectosylvian gyri (which are analogous to the anterior part of the island of Reil in man), the posterior part of the orbital surface of the frontal lobe, and adjacent portions of the olfactory tract. Acceleration of respiration may be produced from (a) the anterior sigmoid and presylvian region, (b) the remainder of the anterior and mid-cingulate gyrus. These effects are most constant under barbiturate narcosis, but may be demonstrated under local anesthesia. With chloralose-urethane, inhibitory effects are inconstant, acceleration frequently resulting from stimulation of so-called inhibitory areas. A previously unreported phenomenon consisting of "shift" from predominantly thoracic to predominantly abdominal respiration also occurred. The maximal stimulus characteristics for inhibition using a square wave stimulus were detd. as 30-60 cycles/sec. and 6.4-12.8 msec. duration.