Figure 1.

The timeline of the Methylprednisolone Suppression Test (MPST) experiment. Rats were habituated, and their jugular veins cannulated as described (see Methods). The corticosterone level was measured for baseline (BL), and 10 min later, methylprednisolone was administered through the cannula. Serial blood samples were collected starting at 20 min post-methylprednisolone administration at 10-min intervals for 90 min to evaluate the suppression of corticosterone following methylprednisolone administration. One day later, rats were exposed to PSS, and behavioral assessments were conducted 7 days post-exposure to PSS, first in the EPM test and 1 h later in the ASR test. On the following day, the rats were sacrificed, and their brains were collected and frozen for future immunohistochemistry assays.