RETICULO-SPINAL INFLUENCES ON STRETCH REFLEXES

Abstract

The outstanding feature of the decerebrate prepn. is an exaggeration of stretch reflexes of antigravity muscles, without irradiation. In the decerebrate cat, appropriate regions of the brain stem reticular formation, excited electrically, exert pronounced facilitatory or suppressor influences upon stretch reflexes. These influences are exerted upon flexor or extensor activity alike, and hence are non-reciprocal or generalized. Observations of vestibular and cerebellar influences upon stretch reflexes are also presented. The former is facilitatory and ipsilateral and is evoked with low frequencies of stimulation. The latter is suppressor and requires a high frequency of stimulation for its activation.