Vestibular Nucleus

Scopolamine is useful for prevention of motion sickness when the motion is very stressful and of short duration. A transdermal preparation (Transderm-Scop) with a 72-hour duration of action has been marketed for this purpose. Blockade of chohnergic sites in the vestibular nuclei and reticular formation may account for the effectiveness of this agent. When the motion is less stressful and lasts longer, the antihistamines (Hj-antagonists) are probably preferable to the antimus-... 

Bergquist F, Ruthven A, Ludwig M, Dutia MB (2006) Histaminergic and glycinergic modulation of GABA release in the vestibular nuclei of normal and labyrinthectomised rats. J Physiol 577 857-68... 

Grusser-Cornehls U (1995) Responses of flocculus and vestibular nuclei neurons in Weaver mutant mice (B6CBA wv/wv) to combined head and body rotation. Exp Brain Res 707 26-33. 

Similar to other projections from the cerebellar nuclei (except those to the inferior olive which are GABAergic), terminals of cerebellar origin in the red nucleus are enriched in Glu (Schwarz and Schmitz, 1997 Fig. 5). Enrichment of Glu has also been detected in terminals in the oculomotor nucleus originating from the abducens and ventral lateral vestibular nuclei (Nguyen and Spencer, 1999 Fig. 5). 

De Waele C, Abitbol M, Chat M, Menini C, Mallet J, Vidal PP (1994) Distribution of glutaraatergic receptors and GAD mRNA-containing neurons in the vestibular nuclei of normal and hemilabyrinthectomized rats. Eur J Neurosci 6 565-576. 

Popper P, Rodrigo JP, Alvarez JC, Lopez I, Honrubia V (1997) Expression of AMPA-selective receptor subunits in the vestibular nuclei of the chinchilla. Mol Brain Res 44 21-30. 

Sans N, Sans A, Raymond J (1997) Regulation of NMDA receptor subunit mRNA expression in the guinea pig vestibular nuclei following unilateral labyrinthectomy. Eur J Neurosci 9 2019-2034. 

Purkinje cells. The recurrent collaterals extend into the molecular layer where they contact basket cells (O Donoghue et al., 1989). The whole collateral arborization is oriented perpendicular to the long axis of the folia, i.e. in the same plane as the dendritic tree of the Purkinje cell. In the cat it measures 300-700 //m in the sagittal and 100 00 m in the transverse direction (Bishop, 1988). The width of the arborization and its penetration in the molecular and granular layers varies for different parts of the cerebellum. Recurrent collaterals of Purkinje cell axons are constituents of the infra- and supraganglionic plexus. The main Purkinje cell axon enters and traverses the white matter to terminate on cells of the cerebellar or the vestibular nuclei. 

Steady state concentrations of adenosine are maintained through the activities of only three enzymes, 5 -nucleotidase (5 -N), adenosine kinase and adenosine deaminase. Adenosine kinase and adenosine deaminase were located mainly in the soluble fractions of rat cerebellar homogenates, whereas 5 -N was present in subcellular fractions (Philips and Newsholme, 1979), mainly in the synaptosomal fraction (Marani, 1977). Adenosine deaminase-immunoreactivity in rat cerebellum was present with one out of five polyclonal sera prepared by Nagy et ah (1988). Staining was present in most Purkinje cells with a variation in intensity. Staining was observed in the Purkinje cell axons and terminals in the cerebellar and vestibular nuclei. The localization of 5 -N will be discussed below. 

The (central) cerebellar nuclei and the lateral vestibular nucleus of Deiters receive the axons of the Purkinje cells of the cerebellar cortex and serve as the main output stations of the cerebellum. The vermis and the flocculus also project to other vestibular nuclei, but here the Purkinje cell axons compete with vestibular root fibers, intrinsic and commissural vestibular connections and projections from the medial cerebellar nucleus and, therefore, are not the dominant afferent system. 

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. 

Jansen and Brodal (1940, 1942) studied the corticonuclear projection of the corpus cerebelli with the Marchi method in cat, rabbit and mactique. They confirmed the uncrossed projection of each hemivermis to the medial nucleus and the vestibular nuclei. In the hemisphere they distinguished an intermediate zone, that projects to Brunner s (1919) interpositus nucleus and a lateral zone, that is connected with the lateral nucleus. They noticed the correspondence between their three-zonal arrangement in the corti-... 

Fig. 120. Compartments in the white matter of the cerebellum of the cat. Drawings and reconstructions from Haggqvist and AChE-stained sections. Compartments are indicated with different symbols. A-D. Graphical reconstructions of the rostral aspect of the anterior lobe (A) and the posterior lobe (B), the dorsal aspect (C) and the caudal aspect (D) of the cerebellum. Compare Fig. 98. E-G. Transverse sections. A = A compartment ANS = ansiform lobule ANT = anterior lobe B = B compartment Cl-3 = Cl-3 compartments cr = restiform body D(l,2) = D(l,2) compartments F = fastigial lateral cerebellar nucleus PFL = paraflocculus PMD = paramedian lobule SI = simple lobule vest = vestibular nuclei X = X compartment III-IX = lobules IIl-IX.

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).

Fig. 130. Schematic summary of cysteine sulfinic acid decarboxylase (CSADCase)-positive sagittal microzones or bands in mouse cerebellum. The bands are clearest in the anterior lobe and the vermis, less sharply defined in the hemispheres (dense stipple), and most difficult to discern in the paraflocculus and flocculus (light stipple), because of intense CSADCase reactivity in most Purkinje cells. The dentate (D), interpositus (I), fastigial (F), and lateral vestibular nuclei (LVN) contain numerous CSADCase-positive cells. Chan-Palay et al. (1982b).

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