Recent research in our laboratory has revealed a dysregulation of the hypothalamic-pituitary-adrenal axis in monkeys with a veterinary record of self-inflicted wounding (SIB) Monkeys with SIB showed significantly lower AM basal cortisol (as derived from blood samples) than controls To evaluate this relationship more fully and to establish linkages directly to behavioral state, we developed a noninvasive point-sampling procedure for measuring pituitary-adrenal activity In adult monkeys, cortisol is usually measured in blood (typically requiring restraint or sedation) or urine (reflecting a state rather than point estimate) However, cortisol can also be measured in saliva There are at least three advantages to saliva collection 1) it is less invasive than drawing blood and may more accurately reflect basal levels, 2) it allows for repeated sampling within a short period of time, and 3) sampling can be linked directly to behavioral activities such as episodes of self -biting Although protocols exist for collecting saliva from young monkeys, these procedures are inadequate for awake, unrestrained adult animals Our laboratory has developed two methods for collecting saliva from adult rhesus monkeys a """"""""screen"""""""" method, which involves licking screen-covered gauze, and a """"""""pole"""""""" method, which involves sucking and chewing on an attached rope Twenty-three adult male rhesus monkeys were used to evaluate these two methods After a period of adaptation, saliva samples were collected from 20 of 23 subjects Saliva collection was faster with the pole (1-4 min) than with the screen (>6 min) method, but the pole method was not suitable for some animals because of their tendency to bite off the attached rope A preliminary analysis of 5 saliva samples revealed a mean cortisol concentration of 1 85 _g/dl (range 0 48-5 03 _g/dl) These values fall within the expected range Our results indicate that either technique can be used to safely collect saliva f rom unrestrained adult monkeys Choice of technique will depend on the proclivities of individual monkeys We plan to use this technology to link pituitary-adrenal activity directly to behavioral events
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