Effects of sugar rich diet on brain serotonin, hyperphagia and anxiety in animal model of both genders

Lower levels of 5-hydroxytryptamine [5-HT; serotonin] in the brain elicit sugar craving, while ingestion of sugar rich diet improves mood and alleviates anxiety. Gender differences occur not only in brain serotonin metabolism but also in a serotonin mediated functional responses. The present study was therefore designed to investigate gender related differences on the effects of long term consumption of sugar rich diet on the metabolism of serotonin in the hypothalamus and whole brain which may be relevant with the hyperphagic and anxiety reducing effects of sugar rich diet. Male and female rats were fed freely on a sugar rich diet for five weeks. Hyperphagic effects were monitored by measuring total food intake and body weights changes during the intervention. Anxiolytic effects of sugar rich diet was monitored in light-dark transition test. The results show that ingestion of sugar rich diet decreased serotonin metabolism more in female than male rats. Anxiolytic effects were elicited only in male rats. Hyperphagia was comparable in both male and female rats. Finings would help in understanding the role of sugar rich diet-induced greater decreases of serotonin in sweet craving in women during stress

Suppression and treatment of haloperidol induced extra-pyramidal side effects and anxiety syndrome by the coadministeration of red rice bran oil in rats

Antipsychotic medications may reduce or eliminate symptoms of psychosis. They are not a 'cure' for mental illnesses, but can be an effective part of treating mental disorders. Even though many of the antipsychotics such as haloperidol cannot cure mental illnesses, they are effective in eliminating or reducing psychotic symptoms. However, prolong administration of haloperidol may result in parkinsonian like effects and tardive dyskinesia. The objective of the present research was to determine the effects of long term co-administration of RRBO in diet on haloperidol induced anxiety and EPS. It was hypothesized that co-administration of RRBO by the free radicals scavenging property could alleviate parkinsonian like effects and tardive dyskinesia. The present results showed a reversal of haloperidol induced parkinsonian like effects and tardive dyskinesia in rats cotreated with RRBO

Reversal of haloperidol induced motor deficits in rats exposed to repeated immobilization stress

Stress is defined as a non specific response of body to any physiological and psychological demand. Preclinical studies have shown that an uncontrollable stress condition produces neurochemical and behavioral deficits

The present study was conducted to test the hypothesis that a decrease in the responsiveness of somatodendritic 5-hydroxytryptamine [5-HT]-lA receptors following adaptation to stress could attenuate haloperidol induced acute like effect. Results showed that single exposure [2h] to immobilization stress markedly decreased food intake, growth rate and locomotor activity but these stress-induced behavioral deficits were not observed following repeated [2h/day for 5 days] exposure of immobilization stress suggesting behavioral tolerance occurs to similar stress

An important finding of present study is a reversal of haloperidol-induced motor deficits in animals exposed to repeated immobilization stress than respective control animals. It is suggested that stress induced possible desensitization of matodendritic 5-HT-1A as well as 5-HT-2C receptors could release dopamine system from the inhibitory influence of >erotonin. On the other hand, an increase in the effectiveness of postsynaptic 5-HT-1A receptors elicits a direct stimulatory influence on the activity of dopaminergic neuron and is possibly involved in the reversal of haloperidol-induced parkinsonian like symptoms in repeatedly immobilized rats

Oral administration of haloperidol at clinically recommended doses elicits smaller parkinsonian effects but more tardive dyskinesia in rats

The present study was designed to monitor extrapyramidal symptoms [EPS] elicited by the oral administration of haloperidol at clinically recommended doses and to compare it with EPS produced when the drug is injected intraperitoneally at doses used in animal research. Rats injected with haloperidol at a dose of 1 mg/kg daily for 5 weeks exhibited akinesia in an open field and impaired motor coordination. Effects of the drug on motor coordination but not on open field akinesia were attenuated gradually from 2-5 weeks of treatment. Oral administration of haloperidol in drinking water at clinically recommended dose exhibited decreased exploratory activity without producing akinesia. Motor coordination was impaired maximally after 3 weeks and tolerance was developed in the drug induced motor impairment after 5 weeks of treatment. Intensity of vacuous chewing movements [VCMs] and tardive VCMs was greater by oral administration than intraperitoneal injections of haloperidol. The present results showed that oral administration of haloperidol expected to produce sustained effect may result in tolerance in acute parkinsonian like effects but more intensity of tardive dyskinesia. We suggest that drugs which may helpful in alleviating tardive dyskinesia may be more useful if person is on oral drug therapy

Reversal of haloperidol-induced motor deficits by mianserin and mesulergine in rats

Although haloperidol is widely prescribed for the treatment of schizophrenia, its beneficial effects are accompanied by extrapyramidal side effects [EPS]. Role of 5-HT-2A/2C receptors in the attenuation of acute Parkinsonian-like effects of typical antipsychotics is investigated by prior administration of mianserin and mesulergine to rats injected with haloperidol. In the first part of study effects of various doses of haloperidol [0.5, 1.0, 2.5 and 5.0 mg/kg] were determined on motor activity and a selected dose [1 mg/kg] was used to monitor attenuation of parkinsonian effects by two different doses of 5-HT-2A/2C receptor antagonists mianserin [2.5 and 5.0 mg/kg] and mesulergine [1.0 and 3.0 mg/kg]. Rats treated with haloperidol at doses of 0.5-5.0 mg/kg exhibited impaired motor coordination and a decrease in exploratory activity in an open field. The dose response curve showed that at a dose of 1 mg/kg significant and submaximal effects are produced on motor coordination and exploratory activity. Coadministration of mianserin and mesulergine attenuated and reversed haloperidol-induced motor deficits in a dose dependent manner. The mechanism involved in the attenuation / reversal of haloperidol-induced parkinsonian like symptoms by mianserin and mesulergine is discussed. Prior administration of mianserin or mesulergine may be of use in the alleviation of EPS induced by conventional antipsychotic drugs. The findings have potential implication in the treatment of schizophrenia and motor disorders

Perception of academic examination stress: effects on serum leptin, cortisol, appetite and performance

Background: Examination stress is a psychological stress that activate hypothalamic-pituitary adrenocortical [HPA] axis to increase circulating levels of glucocorticoids. The fat derived hormone leptin is also released in response to stress-inducing condition. To workout the role of leptin and cortisol in response to perceived levels of examination stress and their effects on academic performance. The present study was designed to monitor the relationship of self reported perceived levels of examination stress on serum levels of cortisol and leptin in female students going to appear in university examination. Methods: Fifty-six female undergraduate students participated in the study. Examination stress, appetite levels were assessed by a questionnaire and blood samples were collected one hour before appearing in the examination. Performance was evaluated from the marks obtained in that particular examination. Results: Serum cortisol levels increased with an increase in the intensity of perceived examination stress. Serum leptin levels increased only in the group under moderate stress while increases in mild and severe stress group were not significant. Mild to moderate stress enhanced performance but severe stress decreased it. Conclusions: The present study shows an inverted U-shaped relationship between self reported different levels of perceived examination stress and academic performance. Keywords: Academic Stress, Cortisol, Leptin, Appetite, Performance

Increase in serotonin-1A receptor responsiveness following haloperidol, withrawal

In view of a role of 5-hydroxtryptamine [serotonin; 5-HT]-1A receptors in the elicitation of extrapyramidal symptoms [EPS], The present study was designed to monitor pre- and postsynaptic responses to a selective 5 HT-1A ligand, 8-hydroxy-2- [di-n-propylamino] tetralin [8-OH-DPAT] following single and repeated [two times a day for 9 days] administration of haloperidol [5 mg/kg] in rats. The intensity of 5 H-T syndrome elicited by 8-OH-DPAT [0.5 mg/kg] was taken as measure of postsynaptic response. 8-OH-DPAT induced decreases of 5-HT metabolism in the striatum and brain were taken as a measure of postsynaptic response. 8-OH-DPAT induced forepaw treading and hyperlocomotion were smaller in haloperidol than saline injected rats. The decreases were not observed following withdrawal from repeated administration of haloperidol. Flat body posture not altered by single injection of haloperidol was enhanced following withdrawal from repeated administration of haloperidol. Haloperidol plus 8OH-DPAT injected animals exhibited comparable levels of 5-HT metabolism in the striatum as well as in the brain. Administration of 8-OH-DPAT significantly decreased 5-HT metabolism in brain but not in striatum of repeated saline injected animals. Conversely, same dose of 8-OH-DPAT injected to haloperidol-injected animals did not decrease 5-HT metabolism in the brain but decreased it in the striatum. The results show an increase in the responsiveness of pre-and postsynaptic 5-HT-responsiveness of post and presynaptic 5-HT-1A receptors may be involved in the greater incidence of EPS in patients treated with neuroleptics such as haloperidol

Dopamine and serotonin neurotransmission in the reinforcing effects of alchol and apomorphine

To determine the role of dopamine and 5-hydroxytryptamine [5-HT; serotonin] in the reinforcing effects of alcohol and apomorphine. Experimental study. Department of Biochemistry, University of Karachi from September to November 2004. The study was conducted on 24 male albino Wistar rats. Reinforcing effects were monitored in a conditioned place preference [CPP] paradigm using a light-dark activity box. Slicing and punching method was used to collect dorsal and ventral striatum. Neurochemical estimations were done by HPLC-EC. Withdrawal from repeated administration of ethanol [1g/kg/day] as well as apomorphine [1 mg/kg/day] elicited reinforcement that could be monitored in a CPP paradigm. CNS depressant effects of ethanol were not altered on repeated administration but CNS stimulatory effects of apomorphine increased. Reinforcing effects of ethanol but not apomorphine were associated with a decrease in dopamine metabolism in the ventral striatum. A decrease in the activity of dopaminergic neurons following withdrawal from repeated administration is involved in the compulsive use of abused drugs