[Emotional stress and sleep: a study of adrenalectomized rats]

Polygraphic recordings were performed during 12-h dark period in 18 adrenalectomized rats with implanted electrodes for ECoG and EMG under normal conditions and following 1-h immobilization period. The exposure of rats to emotional immobilization stress evoked a highly significant increase in sleep which was especially pronounced for the slow wave sleep (about 40% above the control value). The immobilization effect was completely abolished by preliminary treatment with dexametazone (1 mg/kg subcutaneously). Thus, adrenal steroids are involved into the interrelation between the emotional stress and sleep as a link in a negative feedback loop.