Browsing by Author "A.G. Sathyanesan"

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A comparative study of the pineal complex of nineteen species of Indian freshwater fishes
(1981) V.K.S. Sastry; A.G. Sathyanesan
[No abstract available]
A golgi-cox study of tanycytes in the hypothalamic region of the third ventricle in the wild rat, rattus rattus rattus (L.)
(1981) K.P. Joy; A.G. Sathyanesan
In the third ventricle of wild rat, Golgi-Cox-positive tanycytes of varied shape and size are arranged with their perikarya in the ependymal layer and basal processes extending into the core of the subependyma. The basal processes may be smooth and slender, or barbed and branching, and often take circuitous and overlapping courses. In some, the apical part of the perikaryon projects into the ventricle. In the arcuate region, groups of closely arranged tanycytes whose long basal processes end on the arcuate neurons and the portal vessels in the tubero-infundibular sulci are noticed. The tanycytic processes of the median eminence terminate on the portal vessels in the palisade layer. Some tanycytic processes of the mammillary recess even extend up to the ventral surface of the brain and have disc-like terminations. © 1981 S. Karger AG, Basel.
A Golgi-Cox study of tanycytes in the hypothalamic region of the third ventricle in the wild rat, Rattus rattus rattus (L.)
(1981) K.P. Joy; A.G. Sathyanesan
In the third ventricle of wild rat, Golgi-Cox-positive tanycytes of varied shape and size are arranged with their perikarya in the ependymal layer and basal processes extending into the core of the subependyma. The basal processes may be smooth and slender, or barbed and branching, and often take circuitous and overlapping courses. In some, the apical part of the perikaryon projects into the ventricle. In the arcuate region, groups of closely arranged tanycytes whose long basal processes end on the arcuate neurons and the portal vessels in the tubero-infundibular sulci are noticed. The tanycytic processes of the median eminence terminate on the portal vessels in the palisade layer. Some tanycytic processes of the mammillary recess even extend up to the ventral surface of the brain and have disc-like terminations.
A mercurial fungicide-induced nuclear changes in the oocyte of the teleost, Channa punctatus (bloch)
(1986) R.N. Ram; A.G. Sathyanesan
[No abstract available]
A micromorphological and histoenzymological study on the third ventricular ependyma of the teleost Clarias batrachus (L.)
(1978) A.G. Sathyanesan; K.P. Joy
[No abstract available]
A report on the presence of trematode parasites in the brain ventricles of the teleost Channa punctatus (Bloch)
(1981) B.N. Joshi; A.G. Sathyanesan
[No abstract available]
Adrenal histochemistry of the freshwater teleost Labeo rohita (Ham.)
(1979) R.S. Kulkarni; A.G. Sathyanesan
In Labeo rohita the adrenal homologue is situated around the cardinal vein and its branches, in the lymphoidal pronephric head kidney. Although a majority of medullary cells are arranged close to the wall of the blood vessels, some are seen among the cortical cells also. They exhibit positive chromaffin reaction. Two types of medullary cells could be differentiated with the aid of dichromate and glutaraldehyde-silver techniques. After administration of reserpine, marked depletion was noticed among the glutaraldehyde, and dichromate positive cells. The medullary cells give a positive reaction to PAS after Zenker-formol fixation. They intensely react to the ascorbic acid test. The cortical cells are positive to total lipids and phospholipids. In metopirone treated fishes there is a general reduction in the sudanophilic nature of these cells. Δ5-3β HSDH and G-6-PD activity in the cortical cells indicates that they are capable of steroid biosynthesis. Alkaline phosphatase is moderate in the nuclei and weak in the cytoplasm of the medullary cells whereas it is intense in the cortical cells. Acid phosphatase activity was intense in the nuclei and moderate in the cytoplasm of cortical cells whereas it was moderate in nuclei and weak in the cytoplasm of the medullary components. The adrenal components give a positive reaction to monoamine oxidase.
Alcohol inhibition of formalin induced depletion of neurosecretory material in the teleost Clarias batrachus (L.)
(1975) S. Haider; A.G. Sathyanesan
In the normal C. batrachus a fair amount of stainable neurosecretory material (NSM) is always present in all the component parts of the hypothalamo neurohypophysial (NH) complex. When formalin was injected intraperitoneally 70 to 90% of the NSM was depleted from the HN complex. When ethyl alcohol was administered immediately after formalin treatment, the depletion of NSM was inhibited, and their staining intensity could be compared with those of untreated controls.
Ammonium sulfate induced nuclear changes in the oocyte of the fish, Channa punctatus (Bl.)
(Springer-Verlag, 1986) Raj Narayan Ram; A.G. Sathyanesan
[No abstract available]
An in situ Study of the Hypothalamic Neurosecretory System of the Freshwater Catfish Ailia coila (Ham.)
(1972) Shamim Haider; A.G. Sathyanesan
The hypothalamo‐neurohypophysial complex of Ailia coila is well demonstrated with the help of in situ staining procedure. Both pars magnocellularis and pars parvocellularis components of the nucleus preopticus contribute to the formation of the right and the left main neurosecretory tracts. Anterior one third of these tracts are loosely set and posteriorly they became more compact. From the posterior two thirds of the main tracts several pairs of lateral tracts were given off which join at the midline to form the paired median tracts. The median and the main tracts jointly enter the pituitary as the common tract. The common tract on entering the pituitary often divides into two or more branches and enter the pars intermedia independently. The rostral pars distalis is least innervated by the neurosecretory axons. Since the proximal pars distalis has varying amount of AF‐positive cells, and the pars intermedia has the bulk of the neurosecretory axons both these regions are stained dark in the in situ preparations. Bulk preparations provide a clear topographic picture of the entire neurosecretory system, which is very difficult to visualise in tissue sections and in their reconstructions. 1972 The Royal Swedish Academy of Sciences
An in situ study of the preoptico-neurohypophysial complex of the freshwater teleost Ciarias batrachus (L.)
(Springer-Verlag, 1969) A.G. Sathyanesan
The complicated architectural pattern of the preoptico-neurohypophysial neurosecretory system of Clarias batrachus is described using bulk staining procedure. The nucleus preopticus is U-shaped; its limbs constitute the PMC and PPC. The difference in staining intensities noticed among the PMC and PPC might suggest a possible functional difference within the system. Axons of the PMC diagonally pass through the PPC and emerge along with those of the latter to form the right and the left main tracts. The folds and recurrent curves of the neurosecretory axonal tracts, the formation of several pairs of lateral tracts and their union to form median tracts might be devices to increase the storing and releasing capacity for the neurosecretory material. The presence of prominent Herring bodies, and diffuse areas in the neurosecretory tract suggest possible sites of release of neurohormones along the highly vascular hypothalamic region. The common neurosecretory tract is divided into several smaller branches at the level of the pars distalis prior to entering the pars intermedia. Branches do penetrate into the pars distalis, but those entering the rostral component of the pituitary are relatively scarce. Regeneration of the anterior stump of the severed hypophysial stalk to form a neurohypophysis-like organ is also demonstrated in toto with the aid of the bulk staining procedure. A demonstrable increase of stainable neurosecretory material was noticed all along the hypothalamo-neurohypophysial complex of some specimens subjected to complete darkness. Total staining methods could be advantageously used to map the course of recurrent tracts and extra-hypophysial axonal endings. Since the neurosecretory system seems to exhibit a varied structural pattern in different fishes, extension of this study to a larger number of species may throw additional light on the function and the evolution of this important system. © 1969 Springer-Verlag.
Annual cyclical changes in the monoamine oxidase (MAO) activity in the testis of the teleost, Channa punctatus (Bloch)
(1980) B.N. Joshi; A.G. Sathyanesan
Correlative changes in the monoamine oxidase (MAO) activity were recorded biochemically in the testis of Channa punctatus during different phases of the annual reproductive cycle. MAO activity increased with increase in testicular weight and maturity and declined during the postspawning and resting phases. This suggests that MAO may play some role in the growth cycle of the testis. On the other hand, 5-hydroxytryptamine (5-HT) concentration was found to be high in the testis during the resting phase and was markedly reduced during the spawning phase. Thus, there seems to be an inverse relationship between MAO and 5-HT in the testis during its annual cycle. © 1980.
Antagonistic response of chlorpromazine and formalin in effecting quantitative changes in the neurosecretory material in the teleost Clarias batrachus (L.)
(1975) S. Haider; A.G. Sathyanesan
[No abstract available]
Cadmium chloride-induced changes in hypothalamic 5-hydroxytryptamine, noradrenaline and dopamine levels in the Indian palm squirrel, Funambulus pennanti (Wroughton)
(1988) Vinoy K. Shrivastava; A.G. Sathyanesan
A single intraperitoneal injection of cadmium chloride (CdCl2, 0.32 mg/kg body weight) was administered to 15 adult female palm squirrels (Funambulus pennanti (Wroughton)) and the hypothalamic 5-hydroxytryptamine (5-HT), noradrenaline (NA) and dopamine (DA) levels were quantified on the 1st, 7th and 40th day. 5-HT levels significantly decreased on the 1st and 40th day but showed an increase on the 7th day. Similarly, NA levels significantly decreased after 1, 7 and 40 days of treatment, and DA levels decreased on the 1st and 7th day but insignificantly increased on the 40th day. This suggests that CdCl2 interferes in the functioning of the hypothalamo-hypophyseal axis by impairing the hypothalamic 5-HT, NA and DA levels, which may in turn affect the physiology of the peripheral endocrine glands. © 1988.
Cadmium-induced inhibition of brain monoamine oxidase in the freshwater catfish
(Birkhäuser-Verlag, 1984) S.R. Katti; A.G. Sathyanesan
The freshwater catfish Clarias batrachus (L.), exposed to 50 ppm of cadmium (Cd) chloride for a period of 135 days exhibited marked inhibition of brain monoamine oxidase (MAO) (p<0.001). The retarded gonadal growth observed in the present study suggests that Cd may be capable of creating imbalance in the aminergic activity of the hypothalamus, which modulates the secretion and release of gonadotropins. © 1984 Birkhäuser Verlag.
Changes in tissue lipid and cholesterol content in the catfish Clarias batrachus (L.) exposed to cadmium chloride
(Springer-Verlag, 1984) S.R. Katti; A.G. Sathyanesan
[No abstract available]
Cythion-induced histophysiological changes in thyroid and thyrotrophs of the teleost fish, Channa punctatus (Bloch)
(1989) Raj Narayan Ram; K.P. Joy; A.G. Sathyanesan
The chronic effects of continuous exposure for 6 months, from January to June, to safe (2.0 ppm) and sublethal (4.0 ppm) concentrations of a commonly used organophosphorus pesticide, cythion, on the histophysiology of the thyroid and thyrotrophs in Channa punctatus are described in this investigation. The pharyngeal thyroid of fish of both treated groups exhibited hypertrophy and hyperplasia of the follicular epithelium and reduction of colloid content. Apart from this, in the fish exposed to 4.0 ppm, some of the follicles were exhausted and transformed into degenerated cystic masses. The presence of free blood cells at these sites suggests rupture of blood vessels and possible phagocytosis. These histopathological changes could be correlated with a significant and dose-dependent reduction of thyroidal radioiodine uptake and conversion ratio (serum protein-bound iodine:total serum iodine) values. After cythion exposure, the thyrotrophs in the pituitary were activated. These results suggest that the thyroid dysfunction caused by cythion may be responsible for the stimulation of the thyrotrophs which in turn stimulated the thyroid follicles through the pituitary-thyroid axis in this species. © 1989.
Cytochemical and histoenzymological studies on the adrenal of the teleost, Puntius sophore (Ham.)
(1978) R.S. Kulkarni; A.G. Sathyanesan
[No abstract available]
Demonstration of post-hypophysectomy changes in the neurosecretory system of a fish with in situ staining technique
(Birkhäuser-Verlag, 1969) A.G. Sathyanesan; S. Haider
[No abstract available]
Distribution of monoamine oxidase (MAO) in relation to the hypothalamo-hypophyseal system of the teleost Clarias batrachus (L.)
(Springer-Verlag, 1976) K.P. Joy; A.G. Sathyanesan
Varying degrees of monoamine oxidase (MAO) activity were noticed all along the hypothalamo-hypophyseal neurosecretory tract in C. batrachus. Intense activity was evident on the wall of the secretory cells of the adenohypophysis, neurons of the nucleus preopticus (NPO) and nucleus lateralis tuberis (NLT). However, MAO activity was also observed in the cytoplasm of some neurons in the ventromedian region of the NLT and groups of cells present in the neurohypophyseal ramifications of the pars intermedia. A strong accumulation of formazan granules in the median eminence (ME) and the neuroadeno interface lends further support to the view that C. batrachus has a ME of both the tetrapodan and the teleostean type. The distributional pattern of MAO in the hypothalamus and hypophysis suggests that monoaminergic fibres are probably involved in the secretory mechanism of the releasing factors and pituitary hormones. © 1976 Springer-Verlag.