Optogenetic inhibition of ventral hippocampal neurons alleviates associative motor learning dysfunction in a rodent model of schizophrenia

PLoS One. 2019 Dec 31;14(12):e0227200. doi: 10.1371/journal.pone.0227200. eCollection 2019.

Abstract

Schizophrenia (SZ) is a serious and incurable mental disorder characterized by clinical manifestations of positive and negative symptoms and cognitive dysfunction. High-frequency deep brain stimulation (DBS) of the ventral hippocampus (VHP) has been recently applied as a therapeutic approach for SZ in both experimental and clinical studies. However, little is known about the precise mechanism of VHP-DBS treatment for SZ and the role of hippocampal cell activation in the pathogenesis of SZ. With optogenetic technology in this study, we tried to inhibit neuronal activity in the VHP which has dense projections to the prefrontal cortex, before measuring long stumulus-induced delay eyeblink conditioning (long-dEBC) in a rodent model of SZ. Rats were administrated with phencyclidine (PCP, 3 mg/kg, 1/d, ip) for successive 7 days before optogenetic intervention. The current data show that PCP administration causes significant impairment in the acquisition and timing of long-dEBC; the inhibition of bilateral VHP neurons alleviates the decreased acquisition and impaired timing of longd-dEBC in PCP-administered rats. The results provide direct evidence at the cellular level that the inhibition of VHP neuronal cells may be a prominent effect of hippocampal DBS intervention, and increased activity in the hippocampal network play a pivotal role in SZ.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Behavior, Animal
  • Conditioning, Eyelid
  • Deep Brain Stimulation / methods*
  • Disease Models, Animal
  • Hallucinogens / pharmacology
  • Hippocampus / drug effects
  • Hippocampus / physiopathology*
  • Learning Disabilities / chemically induced
  • Learning Disabilities / physiopathology
  • Learning Disabilities / therapy*
  • Male
  • Neurons / drug effects
  • Neurons / physiology
  • Optogenetics / methods*
  • Phencyclidine / pharmacology
  • Rats
  • Rats, Sprague-Dawley
  • Schizophrenia / chemically induced
  • Schizophrenia / physiopathology
  • Schizophrenia / therapy*

Substances

  • Hallucinogens
  • Phencyclidine

Grants and funding

This work was mainly supported by the National Natural Science Foundation of China (No. 81771213 to J.F. Sui); Natural Science Foundation of Chongqing (No. cstc2019jcyj-msxmx0269 to J. Yao); Chongqing Medical Research Foundation of Science of Health (No. 2019MSXM015 to S.L. Liu). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.