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A Kochhar

Publications and source records attributed to A Kochhar.

23 records · Page 2Linked to original sources

Members of a nicotinic acetylcholine receptor gene family are expressed in different regions of the mammalian central nervous system.

Nicotinic acetylcholine receptors found in the peripheral and central nervous system differ from those found at the neuromuscular junction. Recently we isolated a cDNA clone encoding the alpha subunit of a neuronal acetylcholine receptor expressed in both the peripheral and central nervous system. In this paper we report the isolation of a cDNA encoding the alpha subunit of a second acetylcholine receptor expressed in the central nervous system. Thus it is clear that there is a family of genes coding for proteins with sequence and structural homology to the alpha subunit of the muscle nicotinic acetylcholine receptor. Members of this gene family are expressed in different regions of the central nervous system and, presumably, code for subtypes of the nicotinic acetylcholine receptor.

Amino Acid Sequence↗

Central cholinergic correlates of low dose ethanol-induced locomotor stimulation.

Brain area levels of acetycholine and choline plus the turnover rate of acetylcholine were measured in three strains of rats given low, locomotor-stimulating doses of ethanol. Maudsley reactive (MR/N), Sprague-Dawley, and randomly bred MR/N (MRrb) rats were killed by microwave irradiation and cholinergic function was measured by gas chromatography/mass spectroscopy methods. The results show that the MR/N strain (2 and 5 months old), which elicits enhanced locomotor stimulation after low doses of ethanol, also demonstrates significant increases in cholinergic function at the time of behavioral stimulation. However, after locomotor stimulation, cholinergic parameters returned to normal in these animals. Strains which do not show enhanced locomotor activity after ethanol did not demonstrate significant central cholinergic changes. We conclude that central cholinergic function is related to behavioral stimulation elicited by low doses of ethanol in the MR/N rat strain but not other strains.

Acetylcholine↗

Effects of different liquid diets and sustained ethanol release on alcohol metabolism.

The effects of two liquid diets, Sustacal and Shorey-AIN, on liver alcohol dehydrogenase (ADH) activity and ethanol clearance were tested in rats under conditions of high ethanol exposure for nine days. High blood ethanol levels (BEL) were produced through a combination of an initial intubated dose of ethanol sustained ethanol release tube (SERT), and ethanol as 37% of total energy in the liquid diet. Under free-feeding conditions, rats consumed slightly more ethanol per unit body weight in the Shorey-AIN diet, a diet formulated for rodent nutrition, than in the Sustacal diet, a diet originally intended for human consumption. However, BEL were significantly higher in the Sustacal group than in the Shorey-AIN group. No differences in ethanol clearance rates were observed between the groups. On the other hand, total liver ADH activity was significantly reduced in both the Shorey AIN/ethanol and the Sustacal/ethanol groups, compared to lab chow controls. When the Sustacal diet was fortified with casein and methionine so that the protein content matched that of the Shorey AIN diet, the BEL were no longer significantly higher than those produced by the Shorey AIN/ethanol diet. The results demonstrate the effect of nutritional factors on BEL under conditions of high ethanol load. However, these factors do not appear to alter major characteristics of ethanol metabolism and clearance in our short-term experiments.

Alcohol Oxidoreductases↗

An animal model for low dose ethanol-induced locomotor stimulation: behavioral characteristics.

The present paper describes a rat strain, Maudsley reactive (MR/N), which dramatically and reliably shows enhanced locomotor stimulation in an openfield apparatus after low doses of ethanol. Other strains, Sprague-Dawley and Wistar inbred, do not show stimulation, whereas Maudsley nonreactive rats show a less dramatic and variable response to ethanol, compared to the MR/N strain. Female MR/N rats show greater stimulation than male MR/N rats, and the response is dose-, age-, and apparatus-related. We conclude that low dose ethanol-induced locomotor stimulation in the MR/N rat strain could be a valuable rodent model for studying central neurochemical correlates of alcohol intoxication.

Age Factors↗