Castration reduces the effect of serotonin-1A receptor stimulation on prepulse inhibition in rats

Behav Neurosci. 2003 Dec;117(6):1407-15. doi: 10.1037/0735-7044.117.6.1407.

Abstract

This study examined the interaction between hormones and serotonin-1A (5-HT1A) receptor modulation of prepulse inhibition (PPI) of the acoustic startle response. Male and female rats were gonadectomized; some castrated rats received testosterone- or estrogen-filled implants. Rats were randomly injected with saline or 0.02 or 0.50 mg/kg 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), a selective 5-HT1A receptor agonist. All rats showed a dose-dependent disruption of PPI in response to 8-OH-DPAT. In untreated castrated rats, this disruption was significantly reduced (33% compared with 78% in sham-operated rats). Testosterone treatment reversed this reduction, but estrogen was less effective. Ovariectomized and sham-operated rats showed similar PPI in response to 8-OH-DPAT. These data suggest that the effect of 8-OH-DPAT on PPI in male rats depends on circulating hormone levels, particularly testosterone.

Publication types

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

MeSH terms

  • 8-Hydroxy-2-(di-n-propylamino)tetralin / pharmacology
  • Acoustic Stimulation
  • Animals
  • Castration
  • Dose-Response Relationship, Drug
  • Estradiol / physiology*
  • Female
  • Ion Channel Gating / drug effects
  • Ion Channel Gating / physiology
  • Male
  • Neural Inhibition / drug effects
  • Neural Inhibition / physiology*
  • Ovariectomy
  • Random Allocation
  • Rats
  • Rats, Sprague-Dawley
  • Receptor, Serotonin, 5-HT1A / drug effects
  • Receptor, Serotonin, 5-HT1A / physiology*
  • Reflex, Startle / drug effects
  • Reflex, Startle / physiology*
  • Serotonin Receptor Agonists / pharmacology
  • Testosterone / physiology*

Substances

  • Serotonin Receptor Agonists
  • Receptor, Serotonin, 5-HT1A
  • Testosterone
  • Estradiol
  • 8-Hydroxy-2-(di-n-propylamino)tetralin