Seasonal sexually dimorphic distribution of neuropeptide Y-like immunoreactive neurons in the forebrain of the lizard Podarcis hispanica.
Since neuropeptide Y (NPY) is involved in several sex-specific physiological and behavioral processes, a sexual dimorphic distribution is expected in forebrain areas that take part in the control of reproduction physiology and sexual behavior. This question has been studied in the lizard Podarcis hispanica by comparing the distribution of NPY-like immunoreactive cells in several forebrain areas of males and females during the season of active (spring/summer) and inactive (fall/winter) reproductive activity. Both qualitative observations and statistical analysis (analysis of variance) indicate that the number of reactive cells within two forebrain areas, the lateral septum and the periventricular preoptic nucleus, depends on the sex (P = 0.02) and season (P = 0.03) and that, in fact, intersexual differences depend on the season of the reproductive annual cycle (P = 0.046). Other areas, such as the amygdaloid nucleus sphericus, show neither sexual dimorphism (P = 0.67), nor seasonal variation in the number of reactive cells (P = 0.18), nor seasonal variation of the intersexual differences (P = 0.75). When analyzed independently, the lateral septum shows a clear sexual dimorphism in favour of females (P = 0.003) whereas the number of reactive cells in the periventricular preoptic nucleus is significantly higher (P = 0.006) in males than in females. In the case of the preoptic nucleus, this sexual dimorphism is clearly accentuated during the season of reproductive activity (P = 0.007), but this dependence is not so clear for the lateral septum (P = 0.059).(ABSTRACT TRUNCATED AT 250 WORDS)
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Universitat de València, Facultat de Ciències Biològiques, Departament de Biologia Animal, Spain.
Font
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Martínez-García
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D000818:Animals; D005260:Female; D008116:Lizards / Q000033:anatomy & histology* / Q000378:metabolism; D008297:Male; D009478:Neuropeptide Y / Q000032:analysis*; D011301:Preoptic Area / Q000033:anatomy & histology / Q000737:chemistry; D016548:Prosencephalon / Q000033:anatomy & histology* / Q000737:chemistry; D012621:Seasons; D012686:Septal Nuclei / Q000033:anatomy & histology / Q000737:chemistry; D012727:Sex Characteristics
D009478:Neuropeptide Y