Restraint in primate chair may cause unusual behaviour in baboons; electrocorticographic correlates and corrective...

Whereas primates restrained in a chair may usually be considered 'normal', the behaviour of baboons in this position was considerably altered: their eyes were closed and they only slightly reacted to the approach of the experimenter (opening of the eyes), in contrast with their active behaviour when left free to move about in their cage. When the ECoG was recorded from certain cortical areas (particularly somatic area I), an unusual pattern developed during the restrained state: 'drowsiness rhythms', which typically appear in this area during transition from wakefulness to sleep, developed in long sustained sequences. Administration of diazepam, an anxiolytic drug, caused both the behaviour and the ECoG of the restrained animal to return to normal (i.e., attentive behaviour and ECoG characteristic of the true waking state). The prolonged drowsy-like ECoG and behaviour may therefore underline a reaction to the 'stress' conditions brought on by restraint.