July 23, 2019

Neuronal mechanisms to account for individual differences in psychiatric stress-induced physiological dysfunctions

Mental stress-induced biological responses considerably differ across animals, which may be explained by intrinsic brain activity patterns. To address this hypothesis, we recorded neuronal activity from multiple cortical areas from freely moving rodents that were exposed to social defeat stress. Based on their stress-induced changes such as cardiac signals and social avoidance behavior, the individual animals were classified into stress susceptible and resilient groups. We found that a combination of principal component analysis and the support vector machine algorithm revealed that functional connections across cortical regions could be predictive factors accounting for individual differences in future stress susceptibility. Especially, animals had higher probability to be stress-susceptible when they exhibited lower correlations in theta power across wide ranges of cortical regions before the stress challenge. In addition, stress-susceptible animals exhibited decreased neuronal spikes in the infralimbic cortex, a subregion of the prefrontal cortex. These results suggest neuronal mechanisms underlying individual differences in psychiatric stress-induced physiological dysfunctions.

Abe R, Okada S, Nakayama R, Ikegaya Y, Sasaki T* Social defeat stress causes selective attenuation of neuronal activity in the ventromedial prefrontal cortex.
Scientific Reports, 9:9447 (2019)
Nakayama R, Ikegaya Y, Sasaki T*
Cortical-wide functional correlations are associated with stress-induced cardiac dysfunctions in individual rats
Scientific Reports, 9:10581 (2019)