Tumor necrosis factor(TNF ) is a crucial neuromodulator in the brain. TNF is involved in many physiological events including pain response and sleep. However, the interactions between TNF and anesthetics have not been elucidated yet. In the present study, we investigated the effects of four intracerebroventricular (ICV) doses (1, 10, and 100 pg, and 1 ng) and two intraperitoneal (IP) doses (10 ...

We evaluated the possibility that serotonin (5-HT) mediates defecation induced by corticotropin-releasing hormone (CRH) exogenously administered or released from the central nervous system by stress via the 5-HT3 receptor in rats. Intracerebroventricular (ICV) injection of CRH (1, 3, and 10 μg/rat) dose dependently increased the number of stools excreted in rats, whereas intravenous (IV) inject...

We investigated the effects of intracerebroventricular (ICV) injection of orexin-A on plasma corticosterone (CORT) concentration and brain monoamine metabolism to clarify the mechanism by which ICV orexin-A induced arousal in chicks. In Experiment 1, plasma CORT concentrations were measured as an indicator of hypothalamic-pituitary-adrenal (HPA) axis activity. There was no significant differenc...

Rats near term of pregnancy have an attenuated febrile response to intracerebroventricular (ICV) injection of prostaglandin E1 (PGE1) when they are studied at an ambient temperature below their thermoneutral zone. Given that nonshivering thermogenesis in brown adipose tissue is impaired in rodents near term of pregnancy, it is possible that the attenuated febrile response is forced by impairmen...

The present study was designed to investigate the role of central adrenoceptors in the hypotensive effect of intracerebroventricular (ICV) injection of norepinephrine (NE) in conscious rabbits. Experiments were carried out on 19 adult rabbits (oryctolagus cuniculus) of either sex. A dose-dependent hypotensive response to ICV injection of NE was observed with no significant change in heart rate....

Systemic or hindbrain administration of MK-801, a noncompetitive N-methyl-D-aspartate receptor antagonist, increases meal size. To examine whether MK-801 enhances intake by increasing gastric emptying, we administered MK-801 (2.0 microg/3.0 microl) into the fourth ventricle [intracerebroventricular (ICV)] and measured feeding and gastric emptying of 5-ml NaCl or 15% sucrose loads. In a parallel...

Recent evidence suggests that insulin may influence many brain functions. It is known that intracerebroventricular (icv) injection of nondiabetogenic doses of streptozotocin (STZ) can damage insulin receptor signal transduction. In the present study, we examined the functional damage to the brain insulin receptors on central mechanisms regulating glomerular filtration rate and urinary sodium ex...

Intracerebroventricular (ICV) injection of carbachol into the third ventricle of conscious rabbits increased pupil size and intraocular pressure (IOP). A significant increase of pupil size by 0.6-1.3 mm for 60-90 min was observed with the dose of 1 microgram and an increase of IOP by 1.1-1.9 mmHg for 15-60 min was observed with doses over 10 ng. These responses were due to central cholinergic s...

Type 2 diabetes has been identified as a risk factor for Alzheimer’s disease (AD). Insulin signalling is often impaired in AD, contributing to the neurodegeneration observed in AD patients. One potential strategy to overcome this impairment is to normalise insulin signalling in the brain. In the present study, we have examined the effects of an enzymeresistant analogue of glucose-dependent insu...