Both serotonergic and noradrenergic systems modulate the development of tolerance to chronic stress in rats with lesions of the serotonergic neurons of the median raphe nucleus.

Both serotonergic and noradrenergic systems modulate the development of tolerance to chronic stress in rats with lesions of the serotonergic neurons of the median raphe nucleus. Behav Brain Res. 2017 Jun 26;: Authors: Pereira AC, Carvalho MC, Padovan CM Abstract Acute exposure to stress induces significant behavioural changes, while repeated exposure to the same stressor leads to the development of tolerance to stress. The development of tolerance appears to involve the serotonergic projections from the Median Raphe Nucleus (MnRN) to the dorsal Hippocampus (dH), since rats with lesions of this pathway does not develop tolerance to stress. Previous data from our laboratory showed that treatment with imipramine, a serotonin (5-HT) and noradrenaline (NA) reuptake inhibitor, lead to the development of tolerance. However, it remains to be elucidated whether such tolerance involves the participation of the noradrenergic system, apart from the serotonergic projections. Therefore, the aim of this work was to investigate the behavioural and neurochemical effects of chronic treatment with desipramine (NA reuptake inhibitor) or fluoxetine (5-HT reuptake inhibitor) in chronically stressed rats with lesions of the serotonergic neurons of the MnRN. Male Wistar rats with or without lesion in the MnRN were submitted or not to acute (2h) or chronic restraint (2h/seven days) stress and tested in the elevated pus maze (EPM). Treatment with fluoxetine, ...
Source: Behavioural Brain Research - Category: Neurology Authors: Tags: Behav Brain Res Source Type: research