TMT exposure differentially affects PER2 and c-Fos in the central amygdala (CE) based on time of exposure.

TMT exposure altered the rhythm and amount of PER2 expression in the CE amygdala of both groups, resulting in a low level of expression at ZT0 in the TMT0 group, followed by a high level of expression at ZT 6 for both groups, and a low level of expression at ZT 18 for both groups (A). TMT resulted in increased c-Fos expression at ZT 0 only for the TMT0 group, and increased expression at ZT 12 only for the TMT12 group (B). Photomicrographs showing decreased PER2 immunoreactivity in the CE of a TMT0 animal at ZT 0 (C) in comparison to a TMT12 animal (D). Photomicrographs depicting increased c-Fos expression at ZT 0 for a TMT0 animal (E) in comparison to a TMT12 animal (F). *significantly different from control group at that time point (p<0.05) **significantly different from control and experimental group at that timepoint (p<0.05). The values for ZT 0 are repeated as ZT 24. Error bars represent standard errors.