Elsevier

Brain Research

Volume 667, Issue 2, 26 December 1994, Pages 201-208
Brain Research

Photoperiod affects the morphology of a sexually dimorphic nucleus within the preoptic area of male Japanese quail

https://doi.org/10.1016/0006-8993(94)91497-4Get rights and content

Abstract

Changes in the gross and cellular morphology of the nucleus preopticus medianus (POMn) were measured in response to changes in photoperiod in adult male Japanese quail (Coturnix japonica). POMn volume and the soma size of a dorsolateral population of neurons within POMn decreased when birds were moved from long day housing conditions (16L,8D) to short day housing conditions (8L,16D), and then increased again when birds were moved back to long day conditions, presumably as a function of the changes in circulating testosterone that accompanied changing daylengths. Male Japanese quail exhibit sexual behavior only when housed under long day housing conditions that approximate the photoperiod of the spring/summer breeding season, and do not exhibit sexual behavior when housed under short day conditions characteristic of fall/winter. Because POMn is known to be critically involved in the expression of male copulatory behavior, these morphological changes in the adult brain likely represent key functional events associated with the seasonal regulation of sexual behavior in male Japanese quail.

Reference (34)

  • ThompsonR.R. et al.

    Ontogeny of a sexually dimorphic nucleus in the preoptic area of the Japanese quail (Coturnix japonica)

    Dev. Brain Res.

    (1992)
  • WadeJ. et al.

    Sexual dimorphism in the soma size of neurons in the brain of whiptail lizards (Cnemidophorus inornatus)

    Brain Res.

    (1992)
  • WatsonJ.T. et al.

    Testosterone implanted in the preoptic area of the male Japanese quail must be aromatized to activate copulation

    Horm. Behav.

    (1989)
  • YahrP. et al.

    The medial and lateral cell groups of the sexually dimorphic area of the gerbil hypothalamus are essential for male sexual behavior and act via separate pathways

    Brain Res.

    (1993)
  • AdkinsE.K. et al.

    Behavioral responses to sex steroids of gonadectomized and sexually regressed quail

    J. Endocr.

    (1976)
  • AllenL.S. et al.

    Two sexually dimorphic cell groups in the human brain

    J. Neurosci.

    (1989)
  • Alvarez-BuyllaA.

    Mechanisms of neurogenesis in adult avian brain

    Experientia

    (1990)
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