Cholecystokinin tetrapeptide effects on HPA axis function and elevated plus maze behaviour in maternally separated and handled rats.

Deficits in the function of the hypothalamic-pituitary-adrenal (HPA) axis have been suggested to predispose to the development of depression and anxiety disorders. This is mirrored in the animal model "Maternal Separation (MS)" where the stress of repeated separation of rat pups from the dam during early postnatal development results in long lasting alterations in HPA axis function. Cholecystokinin increases serum concentrations of stress axis hormones and might be involved in the dam-pup interaction in rats.

Maternal separation affects male rat copulatory behaviour and hypothalamic corticotropin releasing factor in concert.

Maternal separation (MS) is an animal model of early adverse experience, which is known to affect hypothalamic-pituitary-adrenal (HPA) axis function and various aspects of emotional behaviour. Sexual dysfunction is a prominent symptom in depression and in the present study we investigated the effects of maternal separation on copulatory behaviour and partner preference in adult male rats and paced mating in adult female rats. It has been suggested that corticotropin releasing factor (CRF) inhibits copulatory behaviour in male rats and we therefore examined if changes in male sexual behaviour were accompanied by changes in hypothalamic corticotropin releasing factor protein content.

Increased adult hippocampal brain-derived neurotrophic factor and normal levels of neurogenesis in maternal separation rats.

Repeated maternal separation of rat pups during the early postnatal period may affect brain-derived neurotrophic factor (BDNF) or neurons in brain areas that are compromised by chronic stress. In the present study, a highly significant increase in hippocampal BDNF protein concentration was found in adult rats that as neonates had been subjected to 180 min of daily separation compared with handled rats separated for 15 min daily. BDNF protein was unchanged in the frontal cortex and hypothalamus/paraventricular nucleus.