Background Prenatal alcohol exposure can contribute to a wide range of neurodevelopmental impairments in children and adults including behavioral and neuropsychiatric disorders. In rhesus monkeys we examined whether moderate level prenatal alcohol exposure would alter acoustic startle responses and prepulse inhibition of the acoustic startle (PPI). PPI is a highly quantifiable measure of inhibitory neural processes or sensorimotor gating associated with neuropsychiatric disorders. Methods Acoustic startle and PPI of the acoustic startle was tested in 37 adult rhesus monkeys (Macaca mulatta) from four experimental conditions: (a) moderate level prenatal alcohol-exposed, (b) prenatally-stressed, (c) moderate level prenatal alcohol-exposed + prenatally-stressed, and (d) sucrose controls. Results Prenatal alcohol-exposed monkeys showed a higher magnitude of acoustic startle response and disrupted PPI compared with monkeys not exposed to alcohol prenatally. Monkeys in all conditions showed higher HPA-axis responses after undergoing the startle procedure, but HPA responses were unrelated to startle response magnitude, latency, or PPI. Conclusion Finding altered PPI in monkeys prenatally exposed to a moderate dose of alcohol suggests that reduced sensorimotor gating is one effect of prenatal alcohol exposure. Because reduced sensorimotor gating is observed in many neuropsychiatric disorders, sensorimotor gating deficits could be an aspect of the co-morbidity between FASD and mental health conditions.

No abstract