Castration reduces the effect of serotonin-1A receptor stimulation on prepulse inhibition in rats.
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.
Gogos
Andrea
A
Behavioural Neuroscience Laboratory, Mental Health Research Institute of Victoria, Parkville, Victoria, Australia.
van den Buuse
Maarten
M
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000161:Acoustic Stimulation; D000818:Animals; D002369:Castration; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000502:physiology*; D005260:Female; D015640:Ion Channel Gating / Q000187:drug effects / Q000502:physiology; D008297:Male; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology*; D010052:Ovariectomy; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D044282:Receptor, Serotonin, 5-HT1A / Q000187:drug effects / Q000502:physiology*; D013216:Reflex, Startle / Q000187:drug effects / Q000502:physiology*; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D013739:Testosterone / Q000502:physiology*
D017366:Serotonin Receptor Agonists; D044282:Receptor, Serotonin, 5-HT1A; D013739:Testosterone; D004958:Estradiol; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin