Disorders of proprioceptive responses in monkeys after cerebellar lesions:an analysis using the Denny-Brown Collection

We used the Denny-Brown Research Collection to study in detail the reflex r esponses of monkeys after ablation of the anterior lobe, posterior lobe or the entire cerebellum. The Collection includes written, film and histologic al records, and photographs of the brain at autopsy. Large cerebellar ablat ions severely suppress proprioceptive responses, thereby significantly impa iring the capacity to stand, walk. and hop. Cutaneous reflexes are also imp aired, although more selectively, permitting expression of normally suppres sed responses such as magnet reactions and tactile avoiding responses. Enha ncement (release) of responses to truncal cutaneous stimulation, along with suppression of opposing proprioceptive responses, leads to postures of per sistent flexion. Large cerebellar lesions also interfere with reflex respon ses mediated by visual and vestibular systems. More limited cerebellar abla tions have similar, but less severe effects. (C) 1999 Elsevier Science B.V. All rights reserved.