Blebs in the mouse cerebellar granular layer as a sign of structural inhomogeneity. 1. Anterior lobe vermis.
The cerebellum is a modular structure. However, the size of the fundamental compartments is uncertain, with anatomical methods showing a parasagittal band arrangement but electrophysiological mapping suggesting a finer subdivision into microzones and patches. A new anatomical way to demonstrate compartmentation is described. The cerebellum is fixed by perfusion with 70% ethanol, paraffin-embedded and sectioned. When the sections are rehydrated the granular layer pleats into an elaborate array of blebs. These blebs are seen in both transverse and sagittal sections, found in all lobules of both the vermis and the hemispheres, symmetrical about the midline, reproducible between neighboring sections and between individuals, and bear a constant relationship to the Purkinje cell bands as revealed by zebrin II immunocytochemistry. The data suggest that the granular layer of the adult mouse cerebellum is divided into several thousand modules. These modules may reflect the mossy fiber topography, and may be the anatomical equivalents of the tactile receptive field patches. Such a profound compartmentation has important implication for theories of cerebellar structure and development.
Hawkes
R
R
Department of Anatomy, Faculty of Medicine, University of Calgary, Canada. rhawkes@acsucalgary.ca
Gallagher
E
E
Ozol
K
K
D000818:Animals; D002531:Cerebellum / Q000033:anatomy & histology* / Q000166:cytology / Q000378:metabolism; D000431:Ethanol / Q000494:pharmacology; D005404:Fixatives / Q000494:pharmacology; D005440:Fluid Therapy; D006652:Histological Techniques; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D051379:Mice / Q000033:anatomy & histology*; D008810:Mice, Inbred C57BL; D009419:Nerve Tissue Proteins / Q000378:metabolism; D016612:Paraffin Embedding; D010477:Perfusion; D011689:Purkinje Cells / Q000166:cytology / Q000378:metabolism
D005404:Fixatives; D009419:Nerve Tissue Proteins; C071871:zebrin II; D000431:Ethanol