Evidence of alterations in CB2 receptor expression in cerebral cortex of adult prenatally stressed rats

A BRUSCO, T SAEZ, MR KATUNAR, ES ONAIVI, AP TAGLIAFERRO Y MC. ANTONELLI

San Diego, California. EE.UU.

Congreso; XXXVII Reunión Anual de la Society for Neuroscience; 2007

Society for Neuroscience

Prenatal stress has been associated with various developmental and behavioural alterations that persist throughout life, including increased anxiogenic response and depressive like behavior. We have demonstrated that restraint stress inflicted during the last week of pregnancy increases dopamine and glutamate receptors, concomitantly with astrocytosis and decreased dendritic arborization in forebrain areas of the rat adult offspring. Depression and substance abuse have been associated with stressful events early in life that present high relapse and recurrence even after treatment. We have demonstrated that Japanese depressed subjects show polymorphisms in CB2 gene. In this work we studied the expression of CB2 receptors in brain of adult prenatally stressed rats by immunohistochemistry. We use 90 day old Wistar rats whose mothers were stressed between days 14 to 21 of gestation. The expression of CB2 receptor in brain cortex is restricted to primary apical dendrites and soma of pyramidal neurons as well as to the plasmatic membrane of cortical astrocytes. CB2 immunostaining in adult prenatally stressed rats show a lower expression in pyramidal primary dendrites and higher in cortical astrocytes when compared to control rats. These results are in agreement with the reduced dendritic arborization with loss of synaptic contact and astroglial reaction seen in the brain cortex of prenatally stressed rats seen in our previous work. CB2 brain receptors could be implicated in the depressive-like behaviors associated with prenatal stress.