Medial vestibular nucleus

Inoue S, Kita T, Yamanaka T, Ogawa Y, Nakashima T, et al. 2002. Measurement of 5-hydroxytryptamine release in the rat medial vestibular nucleus using in vivo microdialysis. Neurosci Lett 323(3) 234-238. 

MVeMC medial vestibular nucleus, magnocellular part 60-68, 81-84,... 

MVePC medial vestibular nucleus, parvicellular part 61-68, 81-82,... 

Fig. 81. Bright-field autoradiographs showing pH]quinpirole binding to dopamine D3 receptors to coronal sections of the caudal cerebellum of rat. Note high-density of binding sites over the molecular layer (m) of the nodulus (X). Also note stripes of increased [ H]quinpirole binding over molecular layer of the uvula (IX). g, granular layer 10, inferior olive MVe=medial vestibular nucleus 12, hypoglossal nucleus. Gehlert (1993).

Fig. 103. The cerebellar nuclei of the cat. The transitional U-shaped region of the fastigial and posterior interposed nuclei is indicated by double hatching, be = brachium conjunctivum cr = restiform body DV = descending vestibular nucleus F = fastigial nucleus flo = floccular peduncle Ftail = tail of the fastigial nucleus lA = anterior interposed nucleus IP = posterior interposed nucleus L = lateral cerebellar nucleus LV = lateral vestibular nucleus MV = medial vestibular nucleus SV = superior vestibular nucleus u = uncinate tract Y = group y of Brodal and Pompeiano (1957).

Deiters nucleus with its large AChE-positive perikarya in an unstained neuropil is wedged in between the AChE-rich areas of the group y and the medial vestibular nucleus and reaches far dorsally into the hilus region of the central nuclei. Purkinje cell fibers enter Deiters nucleus as perforating fibers, passing in between the dorsolateral protuberance and the anterior interposed nucleus, and through the middle part of the medial nucleus. More rostrally, where Deiters nucleus has disappeared, the AChE-rich neuropil of the superior and medial vestibular nuclei meet at the oblique border between the two nuclei. 

Fig. 123. Diagram of the corticonuclear projection in the cat. Based on retrograde labelling of Purkinje cells and their axons after injections of HRP in their target nuclei. A = A zone A = Anterior interposed nucleus ANS = ansiform lobule B = B zone C1-C3 = C1-C3 zones CRII = crus II of the ansiform lobule D1-D2 = D1-D2 zones DV = descendng vestibular nucleus F = fastigial nucleus FLOC = flocculus IP = posterior interposed nucleus L = lateral eerebellar nucleus LOB POST = posterior lobe LOB ANT = anterior lobe LV = Deiters nucleus MVmc = magnocellular medial vestibular nucleus MVpc = parvicellular medial vestibular nucleus PFL = paraflocculus PFLD = dorsal paraflocculus PFLV = ventral paraflocculus PMED = paramedian lobule SV = superior vestibular nucleus I-X = lobules I-X. Bigare (1980).

Fig. 124. Comparison of bands of AChE reaction product in the molecular layer of the anterior vermis of cat cerebellum and retrograde labelling of Purkinje cells in B and lateral A zones after an injection of HRP in the vestibular nuclei (A-C) and in the B and X zones after an injection in the lateral fastigial nucleus and the B compartment (D-F). Note different size of Purkinje cells in B and X zones. A = A zone B = B zone Deit = Deiters nucleus DV = descending vestibular nucleus F = fastigial nucleus lA = anterior interposed nucleus MV = medial vestibular nucleus X = X zone. I-V = lobules I-V. Voogd (1989).

The white matter compartments of the flocculus do not simply continue as components of the floccular peduncle, but a reorganization takes place, that directs Purkinje cell axons from the compartments 2 and 4 to the medial vestibular nucleus and of the compartments 1 and 3 to the superior vestibular nucleus. The C2 compartment does not contribute to the floccular peduncle, but leads its fibers towards the posterior interposed nucleus. In monkeys the equivalent of compartment 1 of the rabbit extends in the roof of the fourth ventricle, along the basal interstitial nucleus of the cerebellum (Fig. 148). 

Fig. 150. Diagram of the afferent olivocerebellar projection according to Katayama and Nisimaru (1988) and the efferent projection of the zones of the nodulus to the vestibular and cerebellar nuclei according to Wylie et al. (1994) in the rabbit. P = group 8 of the medial accessory olive DC = dorsal cap of Kooy F = fastigial nucleus IP = posterior interposed nucleus MV = medial vestibular nucleus P cell = Purkinje cell SV = superior vestibular nucleus VLO = ventrolateral outgrowth I-VI = zones of rabbit nodulus, numbered according to Katayama and Nisimaru (1988).

Fig. 151. Diagram of the corticovestibular projections from flocculus, nodulus and uvula in Galago. Note complementarity between the projections of the flocculus and the caudal vermis. Ivn = lateral vestibular nucleus mvn = medial vestibular nucleus spvn = spinal vestibular nucleus svn= superior vestibular nucleus. Haines (1977a).

Fig. 165. The vestibulo-olivary projection in the cat. Localization of terminal fields with antegrade axonal transport of pHJleucine. A. Contralateral projection from the superior vestibular nucleus. B. Ipsilateral projection from the medial vestibular nucleus. C. Bilateral projections from the nucleus prepositus hypoglossi. MAO = medial accessory olive PO = principal olive. Gerrits et al. (1985a).

Fig. 188. Diagram of the origin of the climbing fiber afferents and the projections of the Purkinje cells of the five Purkinje cell zones of the flocculus of the rabbit. The zones and the corresponding white matter compartments containing their Purkinje cell axons and climbing fiber afferents are indicated with the same symbols. 1-4 = compartments and zones 1-4 DC = dorsal cap fl-4 = folia 1-4 of the rabbit flocculus fm = medial folium of the flocculus fp = folium p of the ventral paraflocculus Ip = posterior interposed nucleus MAO = medial accessory olive MV = medial vestibular nucleus SV = superior vestibular nucleus VLO = ventrolateral outgrowth Y = group y. From Tan et al. (1995b,c).

Vestibulocerebellar mossy fibers take their origin from neurons in all vestibular nuclei, with the exception of the Deiters nucleus and a sparse projection from the magnocellular medial vestibular nucleus (Figs 200 and 201). The distribution of neurons projecting to either flocculus or caudal vermis or to both is rather similar and is bilaterally symmetrical. Most neurons were found in the medial, superior and descending vestibular nuclei in this order. Neurons projecting to lobules IX and X, to the flocculus and to both parts of the cerebellum occur in a ratio of 12 4 1 (Epema et al.,... 

Fig. 199. Primary and secondary vestibulocerebellar mossy fiber projections in the rabbit, determined with antegrade axonal transport of [3H]leucine and WGA-HRP. Upper panels sagittal sections lower panels transverse sections through the caudal vermis. K196 ipsilateral distribution of fibers of the vestibular nerve. Gerrits et al., (1989) C2098 bilateral distribution of fibers from the medial vestibular nucleus (MV) K82 bilateral distributions of fibers from the superior vestibular nucleus (SV Thunnissen et al., 1989). Dense termination in the sagittal sections is indicated with heavy hatching, scattered labelled mossy fiber rosettes with light hatching and dots. Note similarity in the distribution of primary and secondary vestibulocerebellar projections.

Fig. 203. Mossy fiber projections to the flocculus and the adjacent paraflocculus in the cat. Based on antegrade tracing experiments with tritiated leucine. Notice the lack of basal pontine and reticulopontine projections to the flocculus and their presence in the medial extension (ME) and the caudal lobules (PFLVc) of the ventral paraflocculus in the upper three diagrams. Vestibulo-cerebellar fibers in lower two diagrams terminate both in the flocculus and the ME. A, AP = stereotactic planes DV = descending vestibular nucleus FL = flocculus LV = lateral vestibular nucleus ME = medial extension of the ventral paraflocculus MV = medial vestibular nucleus NP = nuclei pontis = NRTP = nucleus reticularis tegmenti pontis PFLD = dorsal paraflocculus PFLV(c) = (caudal folium of the) ventral paraflocculus SV = superior vestibular nucleus. Gerrits and Voogd (1989).

Fig. 206. Plots of the distribution of mossy fibers on the dorsal (caudal) surface of lobule IV in the cat. A. Fibers from the central cervical nucleus (Matsushita and Tanami, 1987). B. Fibers from the medial vestibular nucleus (Matsushita and Wang, 1987). C. Fibers from the thoracic cord (Yaginuma and Matsushita, 1987). D. Fibers from the spinal border cells (Yaginuma and Matsushita, 1986). E. Fibers from the external cuneate nucleus (Gerrits, 1985). F. Fibers from the basal pontine nuclei (Gerrits, 1985). G. Localization of AChE in the molecular layer on the dorsal surface of lobule IV. Inset sagittal section of the cerebellum of the cat.

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