title: Asymmetry of the habenulae in the elasmobranch "Scyllium stellare". II. Electron microscopy.
abstract: The structure of the habenular nuclei of the elasmobranch Scyllium stellare has been examined with the electron microscope. There is asymmetry of the left and right habenulae; difference is manifest in their cell types and myelin distribution. The presence in only the left habenula of cells bearing large granules - probably secretory - and of cells with myelinated perikarya suggest a functional diversification of the habenulae. A large variety of synaptic vesicles occur in the habenulae of both sides but we could not demonstrate a preferential localization of one particular type in specific habenular subnuclei. A feature common to all portions of the habenular complex is the presence of multilamellar astroglial formations wrapping cell bodies and synapses.
mesh_terms: D000818:Animals; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D004027:Diencephalon / Q000648:ultrastructure*; D005399:Fishes / Q000033:anatomy & histology*; D008854:Microscopy, Electron; D009413:Nerve Fibers, Myelinated / Q000648:ultrastructure; D009940:Organoids / Q000648:ultrastructure; D013569:Synapses / Q000648:ultrastructure; D013572:Synaptic Vesicles / Q000648:ultrastructure