Differential responses of phosphorylated mitogen-activated protein kinase and phosphorylated cyclic-AMP response element-binding protein immunoreactivity in the rat brain to sub-convulsive pentylenetetrazol

The possible advantage of using multiple phospho-specific antibodies to stu dy changes in brain activity was assessed. For this purpose, rats were inje cted intraperitoneally with either a control treatment or 15 mg/kg pentylen etetrazol. The subconvulsive dose of pentylenetetrazol did not induce marke d behavioural effects. Ten minutes after treatment, the rats were perfused and the brains were dissected. Adjacent brain sections were immunohistochem ically stained for phosphorylated cyclic-AMP response element-binding prote in and phosphorylated mitogen-activated protein kinase. Opposite effects of pentylenetetrazol treatment were observed on the immunoreactivity of these two antibodies within the hypothalamic paraventricular nucleus, the suprao ptic nucleus and the arcuate nucleus. In these regions, pentylenetetrazol t reatment increased phosphorylated mitogen-activated protein kinase immunore activity, but decreased phosphorylated cyclic-AMP response element-binding protein immunoreactivity These findings show that changes in the activity of a brain nucleus can be accompanied by differential changes in the activity of two signal transduct ion pathways, which can be detected immunohistochemically. Therefore, the u se of multiple phospho-specific antibodies may enhance our potential to mon itor changes in brain activity. (C) 2000 IBRO. Published by Elsevier Scienc e Ltd. All rights reserved.