No abstract

Efferent cortical activity from the cerebellum is carried by the Purkinje cells (P-cells, see Fig. 1) which are the final common path (P.e.) of two major synaptic organizations. One is a complex polysynaptic network of dendrites and stellate cells in the superficial molecular or plexiform layer to which apparently both cerebellar afferent systems contribute though its main supply is from the mossy fibres (Mo.a.) over the granular cells (Gr.c.). The other afferent system is the monosynaptic one over the climbing fibres (Cl.a.) to P-cell dendrites along which they climb. These are held to contribute also to the polysynaptic network (Estable, 1923;Scheibel & Scheibel, 1954) and many other complexities are encountered, but to a first approximation the physiologist has to be content with a general subdivision of cerebellar afferents into mono-and polysynaptic ones along the lines suggested.His next concern will be with the two additional systems centered on the P-cells one of which consists of two types of recurrent collaterals (P.r.): Cajal's (1911, fig. 12) 'plexus sous-cellulaire' spreads among the cells below the P-cells and his 'plexus sus-cellulaire' traverses the molecular layer giving off branches on its way. Both types of recurrent collaterals do, however, end up on P-cells.Finally, it would seem highly desirable to be able to elucidate the role of the unique system of basket cells (B-cells) with dendritic receptors in the molecular layer (and possibly elsewhere) and efferent axons (B.e.) surrounding the P-cell itself as well as the non-medullated and part of the medullated portion of its efferent axon (for good illustrations, see Estable, 1923; also Retzlaff, 1954).

No abstract

No abstract

No abstract