Estrogen and/or progesterone administered systemically or to the amygdala can have anxiety-, fear-, and pain-reducing effects in ovariectomized rats

Behav Neurosci. 2004 Apr;118(2):306-13. doi: 10.1037/0735-7044.118.2.306.

Abstract

Estrogen (E2) and/or progesterone (P) in the amygdala may influence anxiety, fear, and pain behaviors. Ovariectomized rats were administered subcutaneous or intra-amygdala vehicle, E2, P, or E2 + P: Effects on open field, elevated plus-maze, defensive freezing, and hot-plate task performance were observed. Subcutaneous E2 + P or intra-amygdala E2, P, or E2 + P increased open field central entries and open arm time in the plus-maze compared with vehicle. Subcutaneous or intra-amygdala E2, P, or E2 + P decreased time spent freezing postshock compared with vehicle. Subcutaneous or intra-amygdala E2 + P increased latencies to lick paws compared with vehicle. Thus, E2 and P may have effects in the amygdala to decrease anxiety, fear, and/or pain responses.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amygdala / metabolism*
  • Animals
  • Anxiety / metabolism*
  • Estrogens / metabolism*
  • Fear*
  • Female
  • Maze Learning
  • Ovariectomy / methods*
  • Pain / prevention & control*
  • Progesterone / metabolism*
  • Random Allocation
  • Rats
  • Rats, Long-Evans

Substances

  • Estrogens
  • Progesterone