Neuro-immunomodulation by dorsolateral hippocampus--role of macrophages,T and B cells

In dorsolateral hippocampal lesioned, Sham and control animals, the total number of splenocytes was determined and macrophages, B cells and T cells were isolated and their percentage distribution in total splenocytes were determined. The leukocyte migration inhibition was studied in these groups using different fractions of splenocytes namely whole splenocytes, macrophage removed fraction, and nylon wool eluted T cell population. The same groups were also studied after an antigenic challenge. The results indicate alterations in the macrophages, adherent cell population as well as T cell population in lesioned and Sham animals and also in their immunized groups. These altered cell sub-populations may be responsible for the altered migration.

Effect of chronic cyanide intoxication on memory in albino rats

Cyanide is a chemical widely used in industry, and is a major environmental pollutant. Its toxicity is caused by inhibition of cytochrome oxidase resulting in histotoxic hypoxia. The effect of sublethal doses of cyanide on memory and hippocampal neurotransmitters was studied in male Wistar strain albino rats. Cyanide reduced the memory along with reduction in the levels of dopamine and 5-hydroxytryptamine in the hippocampus. Pre-existing malnutrition in the animals exaggerated these effects.

Acute noise-induced alterations in the immune status of albino rats

The effect of acute noise induced changes on the immune functions of albino rats was studied. Cell mediated immunity was assessed by Leukocyte migration inhibition index (LMI) and humoral immunity by estimating antibody titre. The organ weight of spleen, thymus, adrenal and lymph node was noted, the cell count of spleen and thymus was enumerated and plasma corticosterone level was estimated. A significant increase in the plasma corticosterone level, thymus weight and cell count along with significant decrease in the antibody titre, spleen weight and cell count was observed in noise stressed animals. No significant changes were observed in the LMI and organ weight of adrenal and lymph node in these animals. Our study shows acute noise to be a potent stressor causing definite alterations in the immune functions of the albino rats.

Neurochemical and behavioural correlates in cassava-induced neurotoxicity in rats

Chronic cyanide intoxication from cassava has been implicated as the cause for a degenerative neuropathy known widely as tropical ataxic neuropathy. An attempt has been made in this study to identify the specific cause for neuropathy caused by cassava using Wistar strain albino rats as the experimental animal model. The results of cassava fed animals were compared with control animals, animals given cyanide, malnourished animals and malnourished animals fed cyanide, to identify the causative factors. This study revealed that though the behavioural pattern in motor coordination of the cassava fed animals was similar to the other groups studied, the neurochemical basis for the observed behavioural pattern was unique for cassava. Hence the neurotoxicity of cassava could be attributed to unmetabolized linamarin, more than its nutritional status and/or cyanide toxicity.

The effect of acute noise stress on neutrophil functions

The effect of acute noise stress on albino rats was studied by estimating the plasma corticosterone level, total leukocyte count and differential leukocyte count. Neutrophil function was assessed by Candida phagocytosis and Nitroblue tetrazolium reduction test. The total leukocyte count was significantly decreased. No significant changes were observed in the differential count of the leukocytes. A significant increase in the plasma corticosterone level, Candida phagocytosis and Nitroblue tetrazolium reduction was observed indicating acute noise to be a potent stressor in albino rats.

Effect of Cassava on motor co-ordination and neurotransmitter level in the albino rat

The root of Cassava, a tropical plant, is consumed in the tropics and has been attributed as the cause for various tropical neuropathies. This study aims to discover the neurotoxic effects of chronic cassava consumption of Indian origin and the effect of malnutrition. The assessment is based on the motor co-ordination and brain neurotransmitters in rats. Cassava consumption reduced the motor co-ordination, but the changes in neurotransmitter levels due to cassava consumption (except for 5HT in corpus striatum) was identical with malnutrition-induced changes, indicating that the toxicity of chronic cassava consumption (of Indian origin) is mainly due to the associated protein calorie malnutrition (PCM).

Antistressor effect of Withania somnifera

Withania somnifera is an Indian medicinal plant used widely in the treatment of many clinical conditions in India. Its antistressor properties have been investigated in this study using adult Wistar strain albino rats and cold water swimming stress test. The results indicate that the drug treated animals show better stress tolerance.

Effect of Ocimum sanctum Linn on noise induced changes in plasma corticosterone level

Ethanol extract of leaves of ocimum sanctum was screened for its antistressor actions against acute and chronic noise stress in albino rats by investigating the plasma corticosterone level in these animals. There was a significant elevation of the corticosterone level in plasma of rats subjected to 30 min noise (100 dB) stress. Chromic exposure (4 hr daily for 30 days) to noise with same intensity reduced the hormonal level significantly. Treatment of animals with ethanol extract of Ocimum sanctum prevented the changes in plasma level of corticosterone induced by exposure to both acute and chronic noise stress, indicating the antistressor property of the plant against noise.

Regional specificity seen within hypothalamus in neuroimmunomodulation

Wistar strain male albino rats lesioned and sham lesioned at Ventromedial hypothalamus (VMH) were used to study the neuroimmunomodulation by this brain region. Except the decrease in thymus weight/body weight ratio (P < 0.01), and its cellularity (P < 0.02) in immunized VMH lesion animals, the rest of the parameters like plaque forming cells (PFC), antibody titre, leukocyte migration inhibition index, foot pad thickness in the lesioned as well as the lesion immunized animals never deviated from their respective sham and immunized sham animals. Sham operated belongs to VMH when compared to control rats, showed marked decrease in spleen weight (P < 0.001), thymus weight (P < 0.02) and decrease in popliteal lymph node weight (P < 0.001) ratios. After immunization, the immunized sham animals showed a marked decrease in antibody titre (P < 0.05), PFC (P < 0.05), spleen (P < 0.05) and thymus (P < 0.001) weight ratios with the significant increase in splenic cell count (P < 0.01) compared to immunized control rats. VMH may be one of the information receiving center. However, from these results, it is inferred that VMH could not be a modulating center for the many of the parameters studied as far as neuroimmunomodulation is concerned.

Peripheral immune response in albino rats following cerebroventricular and intraperitoneal antigen challenge

Success in neural tissue transplants at central nervous system suggest that the site may be immunologically privileged. However, this experimental study in which an antigen (Sheep Red Blood Cells) was administered into the third ventricle does not support the above concept. The antibody titre and soluble immune complex levels seen in these animals are similar to the levels seen in animals immunized with the same amount of antigen through the intraperitoneal route. Intraventricular immunization is rather a more potent modulator in decreasing the total WBC count (P < 0.05) and neutrophils (P < 0.001). Further a marked increase in lymphocytes (P < 0.01) in peripheral blood was observed in these animals. Intraventricular immunization also increased the killing power (NBT reduction) of the neutrophils (P < 0.05).

Activated charcoal--an antidote to methyl alcohol poisoning

Every year a considerable number of people die due to methly alcohol poisoning, in which most of them die even before they are given proper treatment. This report gives a simple and cheap first aid measure to those affected by methanol poisoning by the administration of activated charcoal. This study has shown that the mortality of methanol recipient rats have significantly reduced by the administration of activated charcoal.

Norepinephrine and epinephrine levels in the brain of alloxan diabetic rats

Thirty days after induction of experimental diabetes the brain catecholamines namely, norepinephrine (NE) and epinephrine (E) were studied in discrete brain regions (striatum, hippocampus, hypothalamus, midbrain, pons and medulla, cerebellum and cerebral cortex) in control, alloxan-diabetic untreated and insulin-treated diabetic rats. E showed significant increase in striatum, hippocampus and hypothalamus, whereas NE was increased in hypothalamus, and decreased in pons and medulla significantly in untreated diabetic rats. These effects were not seen in the insulin-treated diabetic rats.

Potassium channel blockade amplifies cardiac instability numerical studies of torsades de pointes

Suppression of responses to premature stimulation has been the guiding principle in managing many cardiac arrhythmias. Recent clinical trails revealed that sodium channel blockade increased the incidence of re-entrant cardiac arrhythmias resulting in sudden cardiac death, although the physiologic mechanism remains uncertain. Potassium channel blockade offers an alternative mechanism for suppressing responses to premature stimuli. We have developed a simple model of a 2D sheet of excitable cells. We can initiate re-entrant activation with stimuli timed to occur within a period of vulnerability (VP). Reducing the Na conductance increases the VP while reducing the K conductance increases the collective instability of the array, and arrhythmias similar to torsades de pointes seen in patients subjected to K channel blocked can be readily initiated. Thus, while K channel blockade may suppress excitability by prolonging the action potential duration, it appears to simultaneously exhibit proarrhythmic properties that result in complex re-entrant arrhythmias.

Programme for drawing line graphs on IBM personal computers

A simple program for drawing line graphs on IBM Personal Computers is described here. This program is written in Basic language and is user friendly. This program allows the operator to plot the line graphs with standard error of each of the observations. After plotting suitable legend can also be added at appropriate places in the graph. In the graphic mode a hard copy can be obtained from a dot matrix printer using print screen command.

Modulation of non-specific immunity by hippocampal stimulation

Rats subjected to electrical stimulation of hippocampus (30 min/day for 4 days) showed an increase in the neutrophils in the peripheral blood when compared to sham (P < 0.01) and controls (P < 0.001). They also showed a significant decrease in lymphocytes, when compared to control rats (P < 0.001). Both sham and stimulated animals showed a significant decrease in total white blood cell count when compared to controls (P < 0.001). The phagocytic index of stimulated animals showed a significant increase from control (P < 0.001) and sham (P < 0.001). In addition, the stimulated animals showed a significant (P < 0.001) decrease in plasma corticosterone level when compared to sham and controls.

Finger - pulse volume during co(2) induced panic States

Changes in Fingure-Pulse Volume (FPV) during CO(2) inhalation were studied in patients diagnosed as having Anxiety disorder with history of panic attacks. Waxing and Waning of the FPV was observed in all the cases after CO(2) inhalation, and this pattern was significantly intensified during panic attacks during the study. The significance and the mechanism underlying the same is discussed.

Reticuloendothelial function in acute noise stress

Wistar strain albino rats of either sex were subjected to acute noise stress (3000 Hz at > 97 dB) for 30 minutes. Carbon clearance test was conducted in noise stressed animals immediately after the stress period. Significant (P < 0.001) increase of the clearance constant K was observed in stressed animals compared to the controls, indicating increased phagocytic activity of the reticuloendothelial system.

Finger pulse volume in patients with panic attacks

To study the peripheral blood flow in patients with panic attacks during "Stress" conditions, nine patients with history of panic attacks were subjected to mental stress of arithmetic calculation and room-air voluntary hyperventilation. Finger Pulse Volume (FPV) was significantly altered during the period following mental activity in untreated patients when compared to controls and patients under treatment. There was also an increase in FPV in untreated patients at rest and during recovery after mental stress when compared to the treated patients.