The effect of clonidine on cell survival, glutamate, and aspartate release in normo- and hyperglycemic rats after near complete forebrain ischemia.

The present study was undertaken to investigate the effects of the alpha2 adrenergic agonist, clonidine, on the near complete cerebral ischemia (NCFI) evoked release of glutamate and aspartate from normo- and hyperglycemic rodent brain tissue using microdialysis tissue techniques. Hemodynamic variables, blood lactate, and glucose levels were monitored throughout the 40 min NCFI occlusion period. After 48 h, rats were killed and the extent of neuronal injury was determined in the cortex, striatum, and hippocampus.

Agonist-induced serotonin 2A receptor desensitization in the rat frontal cortex and hypothalamus.

This study examined the time course and possible mechanisms of agonist-induced desensitization of 5-hydroxytryptamine serotonin 2A receptors in the rat frontal cortex and hypothalamic paraventricular nucleus after 1, 4, and 7 days of treatment with (-)-1-(2,5-dimethoxy-4-iodophenyl)2-aminopropane HCl [(-)-DOI] (1 mg/kg i.p.), a selective 5-HT(2A/2C) receptor agonist.

Chronic fluoxetine differentially affects 5-hydroxytryptamine (2A) receptor signaling in frontal cortex, oxytocin- and corticotropin-releasing factor-containing neurons in rat paraventricular nucleus.

Differential adaptive changes in serotonin2A [5-hydroxytryptamine (5-HT)2A] receptor signaling during treatment may be one mechanism involved in the latency of therapeutic improvement with antidepressants, such as fluoxetine. We examined the effects of fluoxetine (2, 3, 7, 21, or 42 days) on hypothalamic 5-HT2A receptor signaling. The hormone responses to an injection of the 5-HT2A receptor agonist (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-amino-propane HCl (DOI) were used as an index of hypothalamic 5-HT2A receptor function.

Neuroendocrine evidence that (S)-2-(chloro-5-fluoro-indol- l-yl)-1-methylethylamine fumarate (Ro 60-0175) is not a selective 5-hydroxytryptamine(2C) receptor agonist.

The 5-hydroxytryptamine(2A) and (2C) (5-HT(2A) and 5-HT(2C)) receptors are so closely related that selective agonists have not been developed until recently with the advent of (S)-2-(chloro-5-fluoro-indol-l-yl)-1-methylethylamine fumarate (Ro 60-0175), a putatively selective 5-HT(2C) receptor agonist. In the present study, Ro 60-0175 was used to analyze the importance of 5-HT(2C) receptors in hormone secretion. Injection of Ro 60-0175 (5 mg/kg s.