Nuclear organization and distribution in the brain regions of the snake headed fish, Channa marulius

BACKGROUND: Morphological variations have arisen due to diverse environmental conditions. Application of cytoarchitectonic criteria permits the delineation of distinct nuclear complexes from the brain region. PURPOSE: Very less information is available on the cytoarchitectonic pattern of the brain, of the giant snake headed murrel, Channa marulius. The murrel is much neglected in neuroanatomical terms and their study is a necessary step in tracing the evolutionary trends. Hence, in the present investigation, the brain of the snake headed fish, Channa marulius has been investigated to reveal the organization of different nuclear complexes. METHODS: Different nuclear complexes were identified and studied using Cresyl violet and Haematoxyline-Eosin staining techniques from the brain region of Channa marulius. RESULTS: Five distinct nuclear complexes namely pars medialis, pars centralis, pars lateralis dorsalis and pars lateralis ventralis respectively were observed in the area dorsalis telencephali and five nuclear groups pars ventralis, pars lateralis, pars dorsalis, pars supracommissuralis and nucleus entopeduncularis were identified in the area ventralis telencephali. CONCLUSIONS: Three nuclear groups namely pars posterioris, pars dorsalis, pars ventralis were identified in preoptic area. The inferior lobes are massive and consist of five circumscrible nuclear complexes. Midbrain consists of optic tectum, torus longitudinalis and tegmentum where different nuclear groups were identified.