Dorsal neuropil

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. 

Serotonin-like immunoreactivity resides in a fine network of varicose fibers in the neuropil of all cerebellar nuclei. This plexus is most dense in the hilar region of the lateral cerebellar nucleus of the rat (Takeuchi et al., 1982), among the small, intrinsic neurons of this region (Chan-Palay, 1977) and in the caudal and dorsal regions of the central nuclei of the opossum (Fig. 117) (Bishop et al., 1985). 

---