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M Patil

Publications and source records attributed to M Patil.

6 recordsLinked to original sources

Effects of ethanol on the excitability of hippocampal granule neurons.

The effects of low dose ethanol treatment on neuronal firing threshold were studied in dentate granule neurons using intracellular recording. A higher threshold for orthodromic activation and lower threshold for somatic activation were observed in 50 mM of ethanol, based on an examination of the excitatory postsynaptic potentials, strength duration and repetitive firing properties. Experiments involving blockade of glutamate-receptor subtypes suggest that an N-methyl-D-aspartate (NMDA) receptor mediated mechanism is implicated in this action of ethanol.

2-Amino-5-phosphonovalerate

Stimulus-activated changes in brain tissue temperature in the anesthetized rat.

A new thin-film, multisensor probe was used to determine tissue oxygen tension, tissue temperature, and electrical activity at two depths below the brain surface in chloral hydrate- or nitrous oxide/halothane-anesthetized rats. Brain tissue temperature at both depths was found to be lower than core temperature by 1-2 degrees C. Electrical activation, spreading depression, and pentylenetetrazol seizures all resulted in transient increases of brain tissue temperature of a few tenths degree centigrade. Vasodilation, induced by hypercapnia or hypoxia, caused a warming of brain tissue. Near-maximum oxygen metabolism, reached upon reoxygenation after severe hypoxia, was accompanied by tissue temperature rises of greater than 1 degree C. It was concluded that brain tissue temperature in the anesthetized rat is lower than core temperature due to extensive radiative and conductive heat loss to the environment through the head. Transient increases in tissue temperature during activation are caused by vasodilation and increased metabolism.

Anesthesia

Purification of rat intestinal cinnabarinate synthase and its possible role in hyperplasia of the small intestine in diabetic rats.

Streptozotocin diabetic rats fed ad libitum exhibited hyperplasia of the small intestine. As compared to the control animals, the intestine of experimental animals grew in weight, length and total RNA and DNA contents. Intestinal cinnabarinate synthase activity in diabetic rats was however significantly lower. Developmental studies in albino rats indicated that, attainment of the terminal and highest activity of the enzyme tends to correspond with cessation of further increase in RNA and DNA contents of the intestine, thereby suggesting a possible relationship between cinnabarinate synthase and the hyperplastic changes observed. It was also observed that some properties of this enzyme, such as Km and Vmax are modified in diabetic condition. The enzyme was purified to apparent homogeneity and some of its kinetic and other properties were studied.

Animals

Brain tissue temperature: activation-induced changes determined with a new multisensor probe.

Local brain tissue oxygen tension, temperature, and electrical potential were continuously and simultaneously measured at each of two different depths in anesthetized, paralyzed rat brain. Brain tissue temperature increases up to 1 degree C were recorded in response to direct electrical stimulation, spreading depression, PTZ-induced seizures, hypercapnia, and hypoxia. An increase in brain tissue temperature was also recorded during reoxygenation after hypoxia. Thus, we have shown that, in this preparation, increases in either blood flow or oxidative metabolism lead to transient warming of the brain.

Animals