Periaqueductal gray is required for controlling chronic stress-induced depression-like behavior

Wei Hao Peng, Hung Wei Kan, Yu Cheng Ho

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)


Background: Enduring exposure to psychological stress is associated with an elevated risk of major depressive disorder (MDD). There is an enormous need to investigate the unexplored mechanisms of MDD. We examined whether pain-free stress alters synaptic transmission, causing depression-like behaviors in the ventrolateral periaqueductal gray (vlPAG), a brain stem nucleus that controls stress-related depression-like behavior. Methods: In the current study, we studied neuronal changes in the vlPAG and behavioral transforms using electrophysiological recordings, behavioral tests, and pharmacological approaches. Results: We found that chronic restraint stress (CRS) diminished glutamatergic transmission in the vlPAG, leading to maladaptive behavioral despair and anhedonia in mice demonstrated by the forced swimming test (FST), tail suspension test (TST) and female urine sniffing test (FUST). Moreover, CRS increased behavioral hypersensitivity shown by the von Frey test. Bath perfusion with the rapid-acting antidepressant (2R,6R)-hydroxynorketamine (HNK) increased both the frequency and amplitude of miniature excitatory postsynaptic currents (mEPSCs) in vlPAG neurons in the CRS and control groups. Functionally, (2R,6R)-HNK directly enhanced the action potential firing rate in vlPAG neurons. Behaviorally, intravlPAG microinjection of (2R,6R)-HNK alleviated chronic restraint stress-induced depression-like behaviors and behavioral hypersensitivity. Conclusions: These results demonstrate that psychological stress-elicited depression-like behavior is related to a remarkable decrease in glutamatergic transmission in the vlPAG. The maladaptive behaviors are attributed to hypoactivity of glutamatergic neurons in the vlPAG, and direct enhancement of glutamatergic neuronal activity in the vlPAG rescues depression-like behaviors. The present results prove that vlPAG is critical for controlling stress-induced depression-like behaviors through alteration of glutamatergic transmission.

Original languageEnglish
Pages (from-to)28-34
Number of pages7
JournalBiochemical and Biophysical Research Communications
Publication statusPublished - Feb 19 2022
Externally publishedYes


  • (2R,6R)-Hydroxynorketamine
  • Depression
  • Electrophysiology
  • Periaqueductal gray
  • Restraint stress

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology


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