CORTICAL PROJECTION ZONE OF CHORDA TYMPANI NERVE IN CAT

Abstract

Detn. of the cortical localization of taste in cat was attempted by mapping the cortical area electrically responsive to stimulation of the chorda tympani. The cortical response to single shock excitation of chorda tympani was a surface-positive wave of 50-100 uV. amplitude and 10-12 msec. latency. Responses were limited to 5-10 sq. mm. cortical area on the orbital surface of the hemisphere superior to the rhinal fissure. Other cortical areas, including the insula, were unresponsive. The chorda tympani-receiving zone is rostral and lateral to the tactile representation for face, but extensively overlaps the tactile representation of tongue. The chorda tympani, like the tactile projection from tongue, is bilaterally represented. The implication of these findings with respect to cortical localization of taste is discussed. The possible participation of fibers other than taste fibers is considered.