Attenuation of stereotyped behaviour by sex steroids.

Effects of sex steroids, testosterone, progesterone, and estradiol on PEA-induced stereotyped behaviour (SB) has been studied in normal, castrated, and ovariectomised mice. Effects of sex steroids on amphetamine-induced sterotypy and hyperactivity are also described. In castrated and ovariectomised mice B-phenylethylamine (PEA) increased SB. Pretreatment with sex steroids attenuated PEA-induced stereotypy in normal, castrated, and ovarietomised mice. Sex steroid pretreatment significantly inhibited PEA- and amphetamine-induced SB, but failed to alter increased motor activity due to amphetamine or PEA. The possible effect of sec steroids on SB through changes in central neurotransmitters are discussed.