An Experimental Analysis of the Catecholamines in Hyperglycemia and Acidosis-Induced Rat Brain

Hyperglycemia and acidosis are the hallmarks of diabetes. Since these factors play an important role in diabetic complications, we have studied the brain catecholamine levels in hyperglycemic and acidotic conditions per se. Experimentally induced hyperglycemia and acidosis are accompanied by significant alterations in the catecholamine levels in discrete areas of the brain. We and others have shown that chronic or acute diabetes in animals, as well as in humans results in altered neurotransmitter levels. In the present study, hyperglycemia maintained by daily external administration of glucose for thirty days showed increased level of dopamine in striatum and hippocampus, elevation of norepinephrine in hippocampus, and increased level of epinephrine in hypothalamus, midbrain and pons medulla. The ammonium chloride induced acidosis demonstrated significant elevation of dopamine in midbrain and significant increase of norepinephrine in hypothalamus and midbrain, and increased level of epinephrine in hypothalamus, pons medulla and cerebral cortex. On the other hand, sodium acetoacetate induced acidosis did not show any significant change in the level of catecholamines in any of the areas studied. In conclusion, the changes in catecholamine levels observed in experimentally induced hyperglycemic as well as in acidotic conditions are closely related to the changes observed in spontaneous or alloxan or streptozotocin diabetic animals, thereby suggesting that these conditions may be responsible for the changes observed in diabetic animals.

Locomotor behavior of bonnet monkeys after spinal contusion injury: footprint study

Analysis of gait functions following spinal cord injury has been widely studied in rats, mice but limited in primates. This investigation was performed to quantitatively analyze the degree of functional recovery in bipedal locomotion in bonnet monkeys after induced spinal cord contusion. The degree of locomotor recovery was examined by measuring four gait variables, viz., tip of opposite foot (TOF), print-length (PL), toe-spread (TS), and intermediary toe-spread (IT) from the recorded hindlimb prints of monkeys using ink and paper technique. Contusion was induced in spinal cord at T12-L1 level in anaesthetized monkeys by using the Allen's weight drop technique. Postoperatively, all spinal contused animals initially showed a significant decrease in TOF, which then gradually increased for longer duration and attained the near normal values by the sixth month. On the other hand, PL, TS, and IT variables in hindlimb prints of contused animals were found to dramatically increase initially and then slowly decrease subsequently. Later there was a recovery to insignificant levels which differed from the corresponding preoperative values by the fifth month. The observations of this study suggest that the functional contributions of the spared fibers, especially in ventral and ventrolateral funiculi, through collateral sprouts or synaptic plasticity that were formed in the contused spinal cord may be responsible for substantial recovery of hindlimb movements. Moreover, based on analysis of footprint variables observed in locomotion in these subjected monkeys, we understand that spinal automatism and development of responses by afferent stimuli from outside the cord could possibly contribute to recovery of the paralyzed hindlimbs.

Behavioral analysis after sciatic nerve compression in albino rats

BACKGROUND

Walking track analysis which has been widely used to examine the recovery of gait functions in rats with sciatic nerve injury.

PURPOSE

The present study was aimed to objectively analyze and quantify the degree of functional recovery in locomotor behavior of rats after inflicting sciatic nerve crush injury.

METHODS

Wistar rats trained on various runways, viz., narrow beam, grid and staircase, were subsequently tested following sciatic nerve crush injury.

RESULTS

Locomotor ability of injured rats on runways gradually recovered to the level that was not significantly different from their corresponding preoperative level by the sixth postoperative week.

CONCLUSION

Conventional run ways can be objectively used for quantification of the level of recovery.

Regulation of protein kinases and coregulatory interplay of S-100beta and serotonin transporter on serotonin levels in diabetic rat brain

Protein kinases are critical component in the regulation of signal transduction pathways, including neurotransmitters. Our previous studies have shown that serotonin (5-HT) altered under diabetic condition was accompanied by alterations of protein kinase C-alpha (PKC-alpha) and CaMKII, and those alterations were reversed after insulin administration. The current study showed that alloxan-induced diabetic animals revealed hyperglycemia and was associated with an increase in the content of 5-HT, PKC-alpha expression and PKC activity (P < 0.05) simultaneously in striatum (ST), midbrain (MB), pons medulla (PM), cerebellum (CB), and cerebral cortex (CCX) from 7 days to 60 days. Although the 5-HT levels in hippocampus (HC) and hypothalamus (HT) were not altered, the PKC-alpha expression and PKC activity showed increases (P < 0.05) in level in HC. Insulin administration reversed all these changes to a normal level. In contrast, the in vitro study has shown that the 5-HT levels correlated with PKC-alpha expressions as well as PKC activity (P < 0.05) only in ST, MB, and CB either after induction with phorbol 12-myristate 13-acetate (PMA) or blocking with chelerythrine, whereas PM and CCX remained elevated (P < 0.05), implying a regulatory role for PKC-alpha only in ST, MB, and CB. However, our consecutive studies have shown that the 5-HT level in PM was regulated by p38-mitogen-activated protein kinase (p38-MAPK) both in vivo and in vitro, whereas the 5-HT level in CCX was coregulated by S-100beta by protein-protein interaction with serotonin transporter (SERT) via 8-bromoadenosine 3',5'-cyclic monophosphate sodium salt (8-Br-cAMP)-induced cAMP/PKAII pathway(s).

Recovery of bipedal locomotion in bonnet macaques after spinal cord injury: footprint analysis

Analysis of the recovery of gait after spinal cord injury has been widely demonstrated in rat and cat models using different behavioral tests and scoring systems. The present investigation was aimed to quantitatively analyze the degree of functional recovery in bipedal locomotion of bonnet macaques after inflicting spinal cord hemisection lesion. To measure the degree of locomotor recovery, we recorded four gait variables, viz., tip of opposite foot (TOF), print length (PL), toe spread (TS), and intermediary toes (IT) using a footprint analyzing technique. Monkeys were trained preoperatively to perform the monopedal hop or bipedal locomotion on runways. Footprints of trained monkeys were recorded using the nontoxic ink and white paper before and after surgery. Surgical hemisection was induced unilaterally in the right side of spinal cord at T12-L1 level of trained monkeys. In hemiplegic monkeys, initially there was a substantial decrease in TOF and PL variables of the paretic limb, which then gradually increased for longer duration and reached the near presurgical values by the 7th and 5th postoperative month, respectively. In contrast to TOF and PL, the recovery of TS and IT variables was quicker, which dramatically increased at first and then slowly recovered to levels not significantly different from the corresponding preoperative values by the 4th postoperative month. The nonparetic limb has also showed mild alterations in all footprint variables but reached the normal values much faster compared to the paretic limb. The alterations in footprint variables of hemiplegic monkeys were examined for a postoperative period of up to 1 year. The findings of this study suggest that the mechanisms underlying locomotor recovery of lesioned macaques may be correlated to the mature function of spinal pattern generator for locomotion under the impact of residual descending and afferent connections. Further, this study also indicates the functional contribution of progressive strengthening of undamaged nerve fibers through a collateral sprouts/synaptic plasticity formed in partially lesioned cord of macaques.

Locomotor behavior of bonnet macaques after spinal cord injury

Analysis of locomotor behavior after spinal cord injury is widely demonstrated in rodents. In the present investigation, the bonnet monkeys (Macaca radiata) were trained preoperatively to walk in bipedal fashion on the uphill and downhill side of a staircase runway. Surgical hemisection was induced unilaterally in the right side of spinal cord at T12-L1 level in trained macaques. The spinal hemisected animals showed significant impairments in bipedal locomotion with few errors on staircase during the initial part of the postoperative period. In subsequent periods, the walking capability of these operated monkeys gradually improved while traversing the staircase and recovered close to preoperative level by the fourth postoperative month, evaluated using a locomotor behavior grading technique. The results of this study demonstrate the recovery of bipedal locomotion of spinal hemisected macaques on the staircase for a postoperative period of up to 1 year. This study suggests that the mechanisms underlying the recovery of locomotor functions in these monkeys to near normal level may be due to the contribution of spared fibers in lesioned spinal cord and/or probably reflect the mature function of the central pattern generator for locomotion in the spinal cord under the control of remaining descending and afferent units.

An acute hyperglycemia or acidosis-induced changes of indolamines level correlates with PKC-alpha expression in rat brain

Hyperglycemia and ketoacidosis are the two most serious factors in acute metabolic complications of both type 1 and type 2 diabetes. Dysfunction of the central nervous system is a well-documented complication of diabetes. We and others have previously reported that acute or chronic diabetes in animal's results in altered brain neurotransmitter levels. In this study, we investigated the effects of acute (7 days) glucose-induced hyperglycemia and sodium acetoacetate (NaAcAc) or ammonium chloride (NH4Cl) induced acidosis on the level of indolamines (5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA)) as well as PKC-alpha expression/activity in discrete areas of rat brain. Glucose-induced (500 mg/kg, bw) hyperglycemic ( approximately 249 mg%) rats showed significant (p<0.05) increase in 5-HT levels in mid brain (MB), pons medulla (PM) and cerebellum (CB), respectively. 5-HIAA level increased in hippocampus (HC) (p<0.05) as compared to control. The rats treated with sodium acetoacetate (NaAcAc) for 7 days (60 mg/kg, bw) showed significant decrease (p<0.05) of 5-HT level in hypothalamus (HT). Whereas, the 5-HIAA level increased in MB (p<0.05). Similarly, the PKC-alpha expression as well as the enzyme activity showed significant increase in HC, MB, PM and CB under glucose-induced hyperglycemia and that changes correlated the changes of indolamines, suggesting that the hyperglycemia may be the major metabolic disorder in diabetic complications.

A short-term diabetes induced changes of catecholamines and p38-MAPK in discrete areas of rat brain

Chronic diabetes is associated with the alteration of second messengers and CNS disorders. We have recently identified that protein kinases (CaMKII and PKC-alpha) and brain neurotransmitters are altered during diabetes as well as in hyperglycemic and acidotic conditions. In this study, we investigated the effects of acute diabetes on the levels of dopamine (DA), norepinephrine (NE), epinephrine (E) and p38-Mitogen-Activated Protein Kinase (p38-MAPK) in striatum (ST), hippocampus (HC), hypothalamus (HT), midbrain (MB), pons medulla (PM), cerebellum (CB) and cerebral cortex (CCX). Alloxan (45 mg/kg) diabetic untreated rats that showed hyperglycemia (>260 mg%), revealed significant increases of DA level in ST (1.5 fold), HC (2.2 fold) and PM (2.0 fold) and the E level also found to be increased significantly in HT (2.4 fold), whereas the NE level was decreased in CB (0.5 fold), after 7 days of diabetes. Immunoblotting study of p38-MAPK expression under identical conditions showed significant alterations in ST, HC, HT and PM (p<0.05) correlated with the changes of catecholamines (DA and E). On the other hand, the above changes were reversed in insulin-treated diabetic rats maintained under normal glucose level (80 -110 mg %). These results suggest that p38-MAPK may regulate the rate of either the synthesis or release of DA and E in corresponding brain areas, but not NE, under these conditions.

Effect of Ocimum sanctum Linn on the changes in central cholinergic system induced by acute noise stress

The ethanolic extract from the leaves of Ocimum sanctum Linn was screened for its effects on the noise induced changes in the central cholinergic system of albino rats by investigating the acetylcholine content and acetylcholinesterase activity in discrete areas of brain. Exposure to noise (10 kHz:100 dB) stress for 30 min caused a significant reduction in total acetylcholine content and increase in the activity of acetylcholinesterase in cerebral cortex, corpus striatum, hypothalamus and hippocampus of brain. Pretreatment of the animals with ethanol extract of Ocimum sanctum leaves for 7 days prevented the noise induced changes in these two cholinergic parameters in all the four areas of brain. The results of the study indicate the protective nature of the plant material on the brain tissues against the detrimental effect of noise stress.

T lymphocyte subsets and immunoglobulins in intracranial tumor patients before and after treatment, and based on histological type of tumors

It has been reported that nervous system and peripheral immune system communicate with each other and the peripheral immune status is depressed in some intracranial tumor (ICT) patients pre operatively. Little is known about the immune status of intracranial tumor patients during the post operative survival period. We thus investigated total T cells (CD 11+), helper/inducer (CD4+) T cells, suppressor/cytotoxic (CD8+) T cells, B cells (CD19+) and serum immunoglobulins in peripheral blood in certain ICT patients before and after treatment, and based on the histological type of the tumors. Post treatment analysis were conducted 30 days after surgical removal of tumor tissue in benign brain tumor patients and 30 days after chemo therapy (CT)/radiotherapy (RT) following surgical removal of tumor tissue in malignant brain tumor patients. Decreased CD11+, CD4+ and increased CD8+ T cell counts were observed in both benign and malignant tumor cases before treatment compared with control subjects. After treatment, CD4+ T cell count increased and CD8+ T cell count decreased than their pre treatment levels. Serum IgA and IgG levels were decreased in both benign and malignant brain tumor patients before treatment than in control subjects. Serum IgM level has been increased in both benign and malignant tumor patients before and after treatment than in control subjects. Anaplastic malignant astrocytoma, medulloblastoma and glioblastoma multiforme patients showed higher IgM level than astrocytoma, meningioma and ependymoma patients. In conclusions, the depressed host cellular immunity in benign and malignant tumor patients before treatment may be due to the changes in CD4+ and CD8+ counts in addition to tumour specific immunosuppressive factors. Treatment procedures such as surgery, CT and RT may play certain role in the post operative depressed immunosuppression in malignant tumor patients. Humoral immune mechanism (CD19+) in the ICT patients was less markedly affected.

Rat hippocampus and primary immune response

During immune challenge hippocampal region shows time-dependent changes in neurotransmitter levels. Hence in the present study the effect of electrolytic lesion in the dorsolateral hippocampus (DLH) and ventral hippocampal formation (VHF) (to create a disturbance in neurotransmitter levels) on humoral immunity in albino rats has been studied along with appropriate controls. Haemagglutination titre, IgM and IgG levels were monitored on the 5th day after an immune challenge by sheep red blood cells (SRBC) suspension. Antigen challenged lesioned animals had low circulating antibody titre levels compared with the controls and their site-specific sham lesioned groups. The IgM levels were significantly lowered in both DLH and VHF lesioned and immunized animals compared to their immunized sham groups as well as immunized controls. However, only immunized VHF lesioned group showed a significant decrease in IgG level from their immunized sham group. It was concluded from the results that an intact hippocampal region is essential for the normal humoral immunity for the primary immune response in rats. Probably VHF region may be required for the secondary immune response as indicated by the alteration in IgG levels in these animals.

Protective effect of diltiazem on cyanide-induced neurotoxicity in Wistar strain rats

Cyanide is a well-established poison known for its rapid lethal action and toxicity. The central nervous system is one of the main target sites for cyanide toxicity. Cyanide not only alters brain biogenic amine levels but also the intracellular calcium levels in the neuronal cells. In the present study the role of calcium channel blocker diltiazem (DIL) in cyanide induced biogenic amine changes was evaluated in the Wistar strain rats. The protective effect of diltiazem pretreatment and diltiazem treatment along with cyanide on the dopaminergic system and the serotonergic system in the corpus striatum were studied. Diltiazem pretreatment was found to prevent cyanide induced changes in both the amines in the corpus striatum. These results suggest that diltiazem may mitigate the harmful effects of cyanide by interfering with influx of calcium ions and release of the biogenic amines.

RETRACTED: Calcium ions: its role in cyanide neurotoxicity

Cyanide is a well-established poison known for its rapid lethal action and toxicity. The central nervous system is one of the main target sites for cyanide toxicity. Cyanide also alters the brain biogenic amine levels. In the present study the role of calcium ions in cyanide toxicity was evaluated using the calcium channel blocker diltaizem (DIL) in Wistar strain albino rats. This study showed that DIL pretreatment prevented cyanide induced changes in the dopaminergic and serotonergic system in the corpus striatum.

Effect of acute noise stress on acetylcholinesterase activity in discrete areas of rat brain

Effect of various stressor agents on the adrenergic system in brain had been studied extensively. However, reports on the effect of stress on various parameters of central cholinergic system are scanty. And very little is known about the effect of noise stress on the cholinergic system in brain. Hence, it was decided to elucidate the effect of acute noise stress on the activity of the enzyme acetylcholinesterase in discrete areas of brain in albino rats. Male albino rats of Wistar strain were subjected to acute noise stress for 30 minutes. The noise of pure sine wave tone was produced by using a function generator and was amplified. The frequency of noise generated was 1 kHz and the intensity was set at 100 dB. The total acetylcholinesterase activity was determined in the tissues of cerebral cortex, corpus striatum, hypothalamus and hippocampus of brain in these rats. The enzyme activity was estimated by colorimetric method using acetylthiocholine iodide as the substrate. The values were compared with the enzyme activity in the control rats. The activity of the enzyme increased significantly in all the four regions of the brain in rats after exposure to noise stress for 30 minutes. The results of the study indicate that the exposure to acute noise stress could modulate the cholinergic system in these areas of brain in rat.

In vitro effect of methanol on folate-deficient rat hepatocytes

Methanol is primarily metabolized by oxidation to formaldehyde and then to formic acid. These processes are accompanied by formation of superoxide anion and hydrogen peroxide. This paper reports the in vitro antioxidant effect of vitamin E on isolated hepatocytes of folic acid deficient rats rendered so as to emulate a human hepatocyte model. These hepatocytes were treated with 320 microM of methanol per million cells and incubated for 30 min. The microsomal fraction of these hepatocytes showed a decreased level of superoxide dismutase (SOD), with increase in lipid peroxidation (LPO) shown by increase in recorded levels of malondialdehyde (MDA). Catalase activity was shown to be increased. Levels of reduced glutathione (GSH) were decreased and the activity of glutathione peroxidase (GSH-Px) and of glutathione reductase (GSSG-R) were not altered. The hepatocytes of folate deficient rats pretreated with vitamin E, when subjected to methanol treatment, showed no significant change in SOD levels and a significant decrease in MDA levels. The catalase activity in this group of animals showed a highly significant decrease. These animals had normal levels of GSH, while a significant fall in GSH-Px and GSSG-R levels were observed. These results suggest that Vitamin E exerts a protective effect on hepatocytes by acting as a free radical scavenger, proving its usefulness in treating methanol toxicity.

Free radical changes in methanol toxicity

Role of free radicals in methanol toxicity was evaluated in methanol treated albino rats. Methanol intoxication increased lipid peroxidation and depleted the free radical scavenging enzyme systems. The free radical quenching effect of vitamin E protected the animals from methanol induced free radical damage.

A comparative study of different crude extracts of Ocimum sanctum on noise stress

Our previous studies have shown that the ethanolic extract of Ocimum sanctum (OS) leaves was effective in alleviating the noise stress induced changes. Hence in this study, we have investigated the effectiveness of different types of crude OS extracts on some of the stress parameters after noise stress. The results of this study has shown that the active principle responsible for antistressor effect of ethanolic extract is also present in cold homogenised leaf extract of OS also. Hot extracts slightly decrease the potency of the active principle in normalizing corticosteroid level.

Effect of chronic protein restriction on motor co-ordination and brain neurotransmitters in albino rats

In this study we evaluated the motor co-ordination in Wistar strain albino rats that were maintained on a protein-restricted diet for a period of 1 year immediately after the weaning period, by substituting 75% of the normal diet with a carbohydrate-rich diet deficient in protein, for a period of 1 year immediately after the weaning period. This type of chronic protein restriction caused disturbances in motor co-ordination. It also caused a significant reduction in the basal levels of dopamine, norepinephrine, epinephrine and serotonin along with their metabolites homovanillic acid (HVA), vanillyl mandelic acid (VMA) and 5-hydroxy indoleacetic acid (5HIAA) and precursor L-dopa in the corpus striatum and cerebellum. Changes in these neurotransmitters could have caused altered co-ordination in the protein-restricted animals.

Effect of Ocimum sanctum on noise induced changes in neutrophil functions

The effect of ethanolic extract of Ocimum sanctum was studied on the noise stress induced changes in albino rats. Acute noise stress caused leukopenia, increased corticosterone level and enhanced the neutrophil functions as indicated by an increase in the Candida phagocytosis and Nitro blue tetrazolium (NBT) reduction. Pretreatment with the O. sanctum Linn. (OS) extract brought back the stress altered values to normal levels indicating the stress alleviating effect of O. sanctum.

Behavioural assessment of functional recovery after spinal cord hemisection in the bonnet monkey (Macaca radiata)

In spinal cord research, current approaches to behavioural assessment often fail in defining the exact nature of motor deficits or in evaluating the return of motor behaviour from lost functions following spinal cord injury. In addition to the assessment of gross motor behaviour, it is often appropriate to use complex tests for locomotion to evaluate the masked deficits in the evaluation of functional recovery after spinal cord injury. We designed a series of sensitive quantitative tests for reflex responses and complex locomotor behaviour in the form of a combined behavioural score (CBS) to assess the recovery of function in the Bonnet monkey (Macaca radiata). Monkeys were tested for various motor/reflex components, trained to cross different complex runways, and to walk on a treadmill bipedally. The overall performance of animal's motor behaviour and the functional status of individual limb movement during bipedal locomotion was graded and scored by the CBS. Surgical hemisection was then performed on the right side of the spinal cord at the T12-L1 level. Spinal cord hemisected animals showed a significant alteration in certain reflex responses such as grasping, extension withdrawal, and placing reflexes, which persisted through 1 year of follow-up. The spinal cord hemisected animals traversed the complex locomotor runways (Narrow beam and Grid runway) with more steps and few errors, at similar levels to control animals. These observations indicate that the various motor/reflex components and bipedal locomotor behaviour of spinal cord hemisected monkeys return to control levels gradually. These results are similar to those obtained in rat models by other investigators. These results demonstrate that the basic motor strategy and the spinal pattern generator for locomotion (SPGL) in adult monkeys for the accomplishment of complex motor tasks is similar, but not identical, to that in adult rats. This suggests that the mechanisms underlying recovery are probably similar in rats and monkeys, but that primates may take a longer duration to achieve the same functional end point.

Effect of cassava consumption on open-field behavior and brain neurotransmitters in albino rats

Diet exerts a critical influence on human biology and thus studies on the interrelationship of nutrition and behavior continues to be a major and important focus of research in the natural experimental sciences. Cassava is known to cause metabolic and neurological derangement on long-term consumption as a staple diet in the tropics. In this article we present the effects of cassava consumption on open-field behavior and catecholamine levels in the hypothalamus of albino rats. Cassava consumption for 30 days alters the emotional status of the rats, with changes in the basal neurotransmitter levels in the hypothalamus. The role of the cyanide (liberated from cassava) and protein deficiency (associated with cassava consumption) has been discussed.

Long-term ingestion of cassava (tapioca) does not produce diabetes or pancreatitis in the rat model

Cassava (tapioca, manihot) is consumed as a staple food in some developing countries. The intake of cassava has been linked to several diseases including fibrocalculous pancreatic diabetes (tropical calcific pancreatitis). There are few long-term studies on the effect of cassava ingestion on the pancreas in animal models. This article reports on the long-term (up to 1 yr) effects of cassava in the rat model. We found that cassava did not produce diabetes in the rat even after a year of cassava feeding. There were transient changes in serum insulin and lipase levels, but the significance of these findings are not clear. There was no histopathological evidence of either acute or chronic pancreatitis, but there were changes of toxic hepatitis in the liver. In conclusion, chronic cassava ingestion up to a year does not lead to either diabetes or chronic pancreatitis in the rat model.

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.