 Women more vulnerable to stress-related psychopathologies  Depression twice as frequent

 CREB= cAMP response element-binding protein  BDNF  Trk B receptor  MEK-ERK pathway  RSK2  CREB phosphorylation on ser133

 Activate HPA axis  PVN secrete CRF  Anterior pituitary synthesis/release ACTH  Adrenal cortex synthesis/release glucocorticoids  Hippocampus impaired  Behavior, metabolism affected

 Hippocampus and dAAC › Learning, memory, attention, conflict monitoring, pain, pleasure, decision making  Hippocampus and PFC › Implicated in depression

 Mechanisms underlying sex differences in stress-related depression  Methods- males/females in each group › 1) No footshock › 2) 6 footshocks on day 42 › 3) Footshocks daily for 3 weeks then no footshocks for 3 weeks › 4) Footshocks daily for 3 weeks; next 3 weeks alternating days of footshocks  2-4= on day 43 rats exposed to light with no shocks (then killed 2 hrs/30 min after)

 Shocked with randomized starting time › unpredictable  10 second light signal preceded each shock  Examined rat brains › Immunohistochemistry analysis › ELISA and western blot

 Males › pCREB in acute and chronic stress groups decreased › CREB in CA2 of acute and chronic stress decreased  Females › No significant changes of pCREB or CREB in stress

 Males › Morphological abnormalities in chronic stress group › Patches=very lightly stained; no pCREB- or CREB-positive cells  Females  No patches (not shown)

 Males (dAAC) › pCREB levels in chronic stress group decreased and abnormal morphology (black arrow)

 Males › pCREB in acute and chronic stress groups decreased  Females › No significant changes of pCREB or CREB in stress

 Males › pCREB in acutely stressed group decreased  Females › No significant changes of pCREB or CREB in stress

 Males › No significant changes in PL or DG  Females › Decrease in chronic stress of PL of PFC › Increase in acute stress of DG

 Rat brains response to stress is different › Male/female  Recovery! › reversible  Antidepressants › Shown to increase CREB and pCREB levels in amygdala (Burton et al. 2007)

 Regulated by other factors other than pCREB and CREB  Other studies › Nuclear factor of activated T cells (Graef et al. 2003)  mRNA= biphasic time course  Protein= monophasic › 4 different RNA transcripts encode for same BDNF protein › Possible uncoupling of BDNF transcriptional and translational mechanisms

 Don’t stress out!!!