Distribution Pattern of Acetylcholinesterase in the Caudal Rhombencephalic Nuclei of an air breathing Teleost, Heteropneustes fossilis

Teleosts which represent the most prominent and diversified group among actinopterygians, are interesting in many features particularly in their complex nervous system in terms of cytoarchitecture, hodology and number of neurons. Present study has been carried out to histoenzymologically map the caudal rhombencephalic nuclei of Heteropneustis fossilis by employing a modified histochemical technique to visualize acetylcholinesterase containing neurons. It is interesting to mention that in the present investigation, most of the nuclei of medulla oblongata including cranial motor nuclei, reticular and raphe nuclei showed strong activity for acetylcholinesterase. The present investigation has also been compared with that of other vertebrates including fishes studied earlier to set a homology among different rhombencephalic nuclei in the light of recent cytoarchitectural & connectional studies.