Prolonged Stress Causes Cell Death in Midbrain Gray Matter

Imaging studies of the brainstem have demonstrated smaller gray-matter volumes in the pons of patients with post-traumatic stress disorder (PTSD). To understand the mechanisms associated with this finding, researchers in China subjected rats to a severe stress paradigm consisting of physical restraint followed by forced swimming.

Compared with the control group, the stressed group showed apoptosis of neurons in the dorsal raphe nucleus, which is situated in the midline of the brainstem, at the upper part of the pons. Histochemical studies suggested that these changes resulted from morphologic mitochondrial alterations leading to intracellular disruption of lysosome membranes, which caused the leaking of thiamine phosphorylase, an enzyme asso…