Involvement of hippocampal serotonin and neuropeptide Y in depression induced by chronic unpredicted mild stress

Brain Res Bull. 2008 Sep 5;77(1):8-12. doi: 10.1016/j.brainresbull.2008.05.010. Epub 2008 Jun 24.

Abstract

Accumulated evidence indicates a role of the hippocampal 5-hydroxy-tryptamine (5-HT) and neuropeptide Y (NPY) in the response to stress and modulation of depression, but it is unclear whether and how the hippocampal 5-HT and NPY systems make contributions to chronic unpredicted mild stress (CUMS)-induced depression. Here we observed that rats receiving a variety of chronic unpredictable mild stressors for 3 weeks showed a variety of depression-like behavioral changes, including a significant reduction in body weight, sucrose preference, and locomotion, rearing and grooming in open field test, and a significant increase in immobility time in forced swimming test. These CUMS-induced behavioral changes were suppressed or blocked by intra-hippocampal injection of 5-HT (31.25 microg/microl) or NPY (10 microg/microl). These data suggest a critical role of reduced hippocampal 5-HT and NPY neurotransmission in CUMS-induced depression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Behavior, Animal / drug effects
  • Behavior, Animal / physiology
  • Body Weight / drug effects
  • Body Weight / physiology
  • Chronic Disease
  • Depressive Disorder / etiology
  • Depressive Disorder / prevention & control*
  • Depressive Disorder / psychology
  • Disease Models, Animal
  • Exploratory Behavior / drug effects
  • Exploratory Behavior / physiology
  • Food Preferences / drug effects
  • Food Preferences / psychology
  • Grooming / drug effects
  • Grooming / physiology
  • Hippocampus / metabolism*
  • Immobilization / physiology
  • Immobilization / psychology
  • Male
  • Microinjections / methods
  • Motor Activity / drug effects
  • Motor Activity / physiology
  • Neuropeptide Y / administration & dosage
  • Neuropeptide Y / metabolism
  • Neuropeptide Y / pharmacology*
  • Rats
  • Rats, Sprague-Dawley
  • Serotonin / administration & dosage
  • Serotonin / metabolism
  • Serotonin / pharmacology*
  • Stress, Psychological / complications*
  • Swimming / psychology

Substances

  • Neuropeptide Y
  • Serotonin