Lordosis in male rats: The facilitatory effect of mesencephalic dorsal raphe nucleus lesion

Masaki Kakeyama, Korehito Yamanouchi

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21 Citations (Scopus)


The dorsal raphe nucleus was destroyed (DRL) by a radiofrequency lesion generator in castrated male rats, and lordosis behavior was observed. Five weeks after the surgery, all animals were implanted with two Silastic tubes containing estradiol (E2). Behavioral tests were started 2 days after implantation of E2 and carried out every other day for 16 days. Castrated control and sham-operated control males showed low incidence of lordosis and low lordosis quotient (LQ) throughout the tests, whereas all the DRL males displayed lordosis and the mean LQ of the group was significantly higher than that of control groups, but lower than that of an ovariectomized female group. These results suggest that the dorsal raphe nucleus plays an important role in inhibiting lordosis in male rat brain.

Original languageEnglish
Pages (from-to)181-184
Number of pages4
JournalPhysiology and Behavior
Issue number1
Publication statusPublished - 1992 Jan



  • Dorsal raphe nucleus
  • Inhibitory system
  • Lesions
  • Lordosis behavior
  • Male rat
  • Midbrain

ASJC Scopus subject areas

  • Experimental and Cognitive Psychology
  • Behavioral Neuroscience

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