Serotonergic transmission plays differentiated roles in the rapid and sustained antidepressant-like effects of ketamine

  • Br J Pharmacol. 2024 Dec;181(23):4874-4889. doi: 10.1111/bph.17324.
Yong-Yu Yin  1 ,  Jiao-Zhao Yan  2 ,  Qian-Qian Wei  3 ,  Si-Rui Sun  4 ,  Yu-Qiang Ding  5 ,  Li-Ming Zhang  1 ,  Yun-Feng Li  1  2
Affiliations
  • 1. Beijing Institute of Pharmacology and Toxicology, State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing, China.
  • 2. Beijing Institute of Basic Medical Sciences, Beijing, China.
  • 3. School of Medicine, Nantong University, Nantong, China.
  • 4. Beijing Ditan Hospital, Capital Medical University, Beijing, China.
  • 5. Department of Laboratory Animal Science, Fudan University, Shanghai, China.
PMID: 39238235 DOI: 10.1111/bph.17324
Abstract

Background and purpose: The emerging antidepressant effects of ketamine have inspired tremendous interest in its underlying neurobiological mechanisms, although the involvement of 5-HT in the antidepressant effects of ketamine remains unclear.

Experimental approach: The chronic restraint stress procedure was performed to induce depression-like behaviours in mice. OFT, FST, TST, and NSFT tests were used to evaluate the antidepressant-like effects of ketamine. Tph2 knockout or depletion of 5-HT by PCPA and 5,7-DHT were used to manipulate the brain 5-HT system. ELISA and fibre photometry recordings were used to measure extracellular 5-HT levels in the brain.

Key results: 60 min after injection, ketamine (10 mg·kg-1, i.p.) produced rapid antidepressant-like effects and increased brain 5-HT levels. After 24 h, ketamine significantly reduced immobility time in TST and FST tests and increased brain 5-HT levels, as measured by ELISA and fibre photometry recordings. The sustained (24 h) but not rapid (60 min) antidepressant-like effects of ketamine were abrogated by PCPA and 5,7-DHT, or by Tph2 knockout. Importantly, NBQX (10 mg·kg-1, i.p.), an AMPA Receptor Antagonist, significantly inhibited the effect of ketamine on brain 5-HT levels and abolished the sustained antidepressant-like effects of ketamine in naïve or CRS-treated mice.

Conclusion and implications: This study confirms the requirement of serotonergic neurotransmission for the sustained antidepressant-like effects of ketamine, which appears to involve AMPA receptors, and provides avenues to search for antidepressant pharmacological targets.

Keywords
5‐HT; AMPA; antidepressant; ketamine; sustained.
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