A physiological role for beta-endorphin in endogenous pain inhibition was investigated by targeted mutagenesis of the proopiomelanocortin gene in mouse embryonic stem cells. The tyrosine codon at position 179 of the proopiomelanocortin gene was converted to a premature translational stop codon. The resulting transgenic mice display no overt developmental or behavioral alterations and have a nor...

The herb Trianthema decandra. L (Aizoceae family) mentioned in Siddha Literatures had been studied in rats for its ability to inhibit gastric secretion and to protect the gastric mucosa against injuries caused by pyloric ligation, swim stress, acetic acid and cytodestructive agent ethanol. The extracts derived successively by using solvents of increasing polarity from the root powder of TD (Pet...

Depressive disorders affect nearly 19 million American adults, making depression and the susceptibility for developing depression a critical focus of mental health research today. Females are twice as likely to develop depression as males. Stress is a known risk factor for developing depression, and recent hypotheses suggest an involvement of an overactive stress axis. As mediators of the stres...

BNST: bed nucleus of the stria terminalis; CRF: corticotropin releasing factor; VTA: ventral tegmental area Recommended journal section: Neuropharmacology This article has not been copyedited and formatted. The final version may differ from this version. ABSTRACT Stress can trigger relapse of drug use in recovering cocaine addicts and reinstatement in rodent models through mechanisms that appea...

Chronic stress has been shown to alter behaviour in both humans and rodents. For example, previous studies have shown that chronic stress can impair skilled motor function in animals. The stress response is defined by an increase in stress hormones, cortisol in humans and corticosterone (CORT) in rodents, both secreted by adrenal glands. CORT can cross the blood brain barrier easily to regulate...

Background: Strenuous exercise and temperature outside the optimum are associated with hypothalamic dysfunction and therefore disruption of fertility in females. The aim of this study was to evaluate serum Estradiol level and follicogenesis in adult mice exposed to forced swimming in different temperature waters. Materials and Methods: Adult female mice were randomly divided into four groups as...

Primate and rodent models of maternal separation have shown that repeated postnatal separation of young from the mother results in long-term changes to neurohormonal systems relevant to depression. To date, however, it remains unclear whether rodents that experience postnatal maternal separation display specific behavioural or biochemical features of depression in adulthood and whether these ch...

Stress induced analgesia has been shown to utilise both non-opioidergic and opioidergic mechanisms. Earlier studies indicate that opiodergic analgesics exhibit corollary changes in blood glucose level. In this study, the changes in blood glucose level by swim induced stress and the influence of exogenous glucose administration on the stress induced antinociception were studied. Stress per se (b...

The stress response is a multifaceted physiological reaction that engages a wide range of systems. Animal studies examining stress and the stress response employ diverse methods as stressors. While many of these stressors are capable of inducing a stress response in animals, a need exists for an ethologically relevant stressor for female rats. The purpose of the current study was to use an etho...