Persistent alteration in behavioural reactivity to a mild social stressor in rhesus monkeys repeatedly exposed to sevoflurane in infancy.
Raper, J. 1,*; De Biasio, J. C. 2,3,5; Murphy, K. L. 4; Alvarado, M. C. 1; Baxter, M. G. 2,3
[Miscellaneous Article]
BJA: British Journal of Anaesthesia.
120(4):761-767, April 2018.
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Background: Socio-emotional development is the expression and management of emotions, which in non-human primates can be examined using responses toward increasing levels of threat. Damage to the limbic system alters socio-emotional development in primates. Thus, neuronal and glial cell loss caused by exposure to general anaesthesia early in infancy might also impact socio-emotional development. We recently reported that repeated sevoflurane exposure in the first month of life alters emotional behaviours at 6 months of age and impairs visual recognition memory after the first year of life in rhesus monkeys. The present study evaluated socio-emotional behaviour at 1 and 2 yr of age in those same monkeys to determine the persistence of altered emotional behaviour.
Methods: Rhesus monkeys of both sexes were exposed to sevoflurane anaesthesia three times for 4 h each time in the first 6 weeks of life. At 1 and 2 yr of age, they were tested on the human intruder task, a well-established mild acute social stressor.
Results: Monkeys exposed to sevoflurane as infants exhibited normal fear and hostile responses, but exaggerated self-directed (displacement) behaviours, a general indicator of stress and anxiety in non-human primates.
Conclusions: Early repeated sevoflurane exposure in infant non-human primates results in an anxious phenotype that was first detected at 6 months, and persists for at least 2 yr of age. This is the first demonstration of such a prolonged impact of early anaesthesia exposure on emotional reactivity.
(C) 2018 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.