Cerebellar ‘respiratory’ area as determined by afferent inputs

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FIBER PROJECTIONS FROM THE CEREBELLAR NUCLEI TO THE POSTERIOR THALAMUS IN THE CAT STUDIED WITH THE WGA-HRP METHOD YOSHIMITSU KATOH, KAZUKO HASHIMOTO, AND SHIGEYUKI DEURA, Department of Anatomy, Fujita Health University school of Medicine, Toyoake, Aichi 470-11, Japan. Although there are a lot of detailed studies on the fiber projections from the cerebellar nuclei to the anterior ventral as well as lateral ventral thalamic nuclei, few is reported on these projections to the posterior thalamic region. To elucidate these projections,

0.01~1 of 2% WGA-HRP(wheat

germ agglutinine-horse-

radish peroxidase) was injected into the posterior thalamic region, and the retrogradely labeled cells were investigated in the cerebellar nuclei.

Results of the

experiment suggested that there are projections from the fastigial nucleus to the bilateral suprageniculate thalamic nuclei, from the fastigial and dentate nuclei to the bilateral and contralateral lateral posterior nuclei respectively, and from all of the cerebellar nuclei to the pretectal areas.

CEREBELLAR 'RESPIRATORY'AREA AS DETERMINED BY AFFERENT INPUTS. DILXAT ABLA: NAOKI HIRAI, TOSHINOBU ICHIKAWA* and YUJI TANAKA*l, Department of Physiology,Kyorin UniversitySchool of Medicine,6-20-Z Shinkawa,Mitaka-shi, Tokyo 181, 'Department of Physiology,Nihon University School of Medicine,30-l Ohyaguchi,Itabashi-ku, Tokyo 173,Japan To explore the cerebellarfunctionallocalization of respiratorymovement,projectionarea of thoracic dorsal spinocerebellartract (DSCT) neurones whose activitywas related to the respirationwas determined by antidromicmappings in the anaesthetized(pentobarbital sodium, 35mg/kg,ip) cat. Seventeen of 32 DSCT neurones were antidromicallyactivatedfrom bilateral intermediateparts of the anterior lobe, contrasting with the unilateral projections in principleof lumbar DSCT neurones. Precise antidromicmappings in single neurones revealed their diffuse projections in the anterior lobe. In the corresponding areas (lobules III-V), cerebellarneurones showing respiratory-related rhythmic activitywere found. Because these areas are for either fore- or hindlimbs,respiratoryafferentsmay subserve the integrationof limb movements with the respiration.

TOPOGRAPHICAL ORGANIZATION OF OLIVO-POSTERIOR VERMIS PROJECTIONS IN RABBIT ;E"E;;UM. mO:O UWJA%WKEIZo OKAHARA, Deoartment of -55. JaDan Y 10 aL Medical Y%?ztiX UZ879 Projections from the medial accesory olive (MAO) to the posterior vermis (lobules VI - VIII) of the cerebellum were studied in rabbits using the retrograde transport of horseradish psroxidase (HRP). Following injections of HRP into the small areas of lobule VIb, VIc, VIIa, VIIb, VIIIa or VIIIb, retrogradely labeled cells were found in corresponding small particular regions of the MAO. Climbing fibers to lobule VIb, VIc, VIIa, and VIIb originate from small areas of the MAO orderly aligned from the caudal to the intermediate MAO. Further, the medial regions of lobules VI and VII are projected from the medial part, and the lateral regions of lobules VI VII from the lateral part of the MAO. On the other hand, following injection of HRP into lobule VIII, labeled neurons were found unexpectedly in the caudal end of the MAO which was the similar region to lobule VIb. The central portion of the caudal MAO was free of labeled neurons. These lobules received projections also from the nucleus and the dorsal cap. These results show that climbing fiber projections to lobule VI,VII and VIII are topographically organized, and that the projection areas to lobules VI-VIII formed a circle surrounding the free area in the caudal MAO.