Histochemical distribution of cholinesterase activity in the hypothalamo-hypophyseal system of the catfish, Heteropneustes fossilis.
The distribution of cholinesterase (ChE) activity was demonstrated in the hypothalamo-hypophyseal system of Heteropneustes fossilis using acetylthiocholine iodide as the substrate. Perikarya of neurons in nucleus lateralis tuberis and the periventricular region of the infundibular recess showed moderate to strong enzyme activity. In the midventral floor of the infundibular recess, the ependymal layer contained ChE-positive neurons, some of which contacted the ventricle. From these neurons, fine beaded axonal processes were seen to run across the fibrous layer close to ChE-positive capillaries. The blood vessels and capillaries in the external palisade layer also showed intense enzyme activity. The distributional pattern of ChE strongly suggests homology of the region with the median eminence of tetrapods. In the pituitary, the neurohypophysis was generally free of enzyme activity except for some displaced neurons, pituicytes, and capillaries. The hypophyseal blood vessels and capillaries showed strong enzyme activity which varied regionally.
Joy
K P
KP
Centre of Advanced Study in Zoology, Banaras Hindu University, Varanasi, India.
D000818:Animals; D002397:Catfishes / Q000378:metabolism*; D002802:Cholinesterases / Q000378:metabolism*; D005260:Female; D007030:Hypothalamo-Hypophyseal System / Q000201:enzymology*; D008297:Male
D002802:Cholinesterases