An Advanced Transcriptional Response to Corticosterone After Single Prolonged Stress in Male Rats

Area of Science:

• Neuroscience
• Endocrinology
• Psychiatry

Background:

• Stress-related neuropsychiatric disorders, including post-traumatic stress disorder (PTSD), are frequently associated with hypothalamic-pituitary-adrenal (HPA) axis dysfunction.
• Increased sensitivity to glucocorticoid negative feedback is a common observation in PTSD patients.

Purpose of the Study:

• To investigate enhanced glucocorticoid receptor (GR) signaling in higher brain areas following the single prolonged stress (SPS) paradigm, a rat model for PTSD.
• To assess the impact of exogenous corticosterone on gene expression in the hippocampus and amygdala of SPS-treated rats.

Main Methods:

• Rats were subjected to the single prolonged stress (SPS) paradigm.
• Corticosterone or vehicle was administered 7 days post-SPS.
• Plasma corticosterone levels and gene expression in the dorsal hippocampus and amygdala were evaluated.

Main Results:

• A rapid and significant change in the expression of known glucocorticoid receptor (GR) target genes was observed within 30 minutes.
• This rapid transcriptional response to exogenous corticosterone occurred exclusively in the SPS-treated group.
• The findings indicate enhanced GR signaling in the hippocampus of SPS-exposed rats.

Conclusions:

• The study extends the understanding of increased glucocorticoid receptor (GR) sensitivity in the context of post-traumatic stress disorder (PTSD).
• Transcriptional responses in the hippocampus are significantly influenced by enhanced GR sensitivity following stress exposure.
• These findings provide insights into the neurobiological mechanisms underlying stress-related disorders.