FRIGHT AND DRUG CONTRACTIONS IN DENERVATED FACIAL AND OCULAR MUSCLES OF MONKEYS

Abstract

The peripheral motor nerve supply to facial or ocular muscles in monkeys was completely destroyed. After degeneration of nerve endings contractions of the paralytic muscles occurred whenever the monkey was angered or frightened. All observations were made on animals which were allowed to run loose in their cages. The contractions associated with fright were augmented with eserine, and could be reproduced by intramusc. injs. of eserine and acetylcholine. In-traven. injs. of acetylcholine produced contractions in the denervated muscles even without eserinization. Atropine did not lessen the contractions induced by fright or those reproduced by acetylcholine. Adrenalin not only failed to yield contractions, but it actually inhibited those obtained with fright or drug. All available data seemed to point to the fact that contractions in denervated muscles induced by fright were due to a substance secreted in the body which was similar in action to acetylcholine. To determine the origin of this substance, the local vasodilator nerve supply was stimulated and interrupted. Neither stimulation nor resection of the cervical sympathetic or infraorbital nerves had any visible effect on the state of the denervated muscles. Extirpation of the sup. cervical ganglion even bilaterally was also without effect, as were resection of both facial, ipsi-lateral oculomotor, and trochlear nerves.