Environmental enrichment alters gene expression of steroidogenic enzymes in the rat hippocampus

Gen Comp Endocrinol. 2011 Mar 1;171(1):28-32. doi: 10.1016/j.ygcen.2010.12.007. Epub 2010 Dec 21.


Neuroactive steroids are synthesized in the central and peripheral nervous systems. The purpose of this study was to analyze the effects of environmental enrichment on neuroactive steroidogenesis in the rat hippocampus. Environmental enrichment rats were housed in a group of nine in a large cage and three groups of pair-housed rats were housed in a standard cage for 8 weeks. The levels of mRNAs for steroidogenic enzymes and proteins in hippocampus were quantified by real-time RT-PCR. Environmental enrichment increased the mRNA expression levels of 5α-reductase-1 and 3α-hydroxysteroid dehydrogenase, which catalyze synthesis of allopregnanolone from progesterone. Hence, environmental enrichment appears to affect allopregnanolone synthesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3-Hydroxysteroid Dehydrogenases / genetics
  • 3-Hydroxysteroid Dehydrogenases / metabolism
  • 3-Oxo-5-alpha-Steroid 4-Dehydrogenase / genetics
  • 3-Oxo-5-alpha-Steroid 4-Dehydrogenase / metabolism
  • Animals
  • Body Weight / genetics
  • Body Weight / physiology
  • Gene Expression Regulation / genetics
  • Gene Expression Regulation / physiology
  • Hippocampus / enzymology*
  • Hippocampus / metabolism
  • Male
  • Organ Size / genetics
  • Organ Size / physiology
  • Pregnanolone / metabolism
  • RNA, Messenger
  • Random Allocation
  • Rats
  • Rats, Wistar
  • Restraint, Physical
  • Reverse Transcriptase Polymerase Chain Reaction


  • RNA, Messenger
  • Pregnanolone
  • 3-Hydroxysteroid Dehydrogenases
  • 3-Oxo-5-alpha-Steroid 4-Dehydrogenase