The volume of the toad medial amygdala-anterior preoptic complex is sexually dimorphic and seasonally variable

@article{Takami1984TheVO,
  title={The volume of the toad medial amygdala-anterior preoptic complex is sexually dimorphic and seasonally variable},
  author={Shigeru Takami and Akihisa Urano},
  journal={Neuroscience Letters},
  year={1984},
  volume={44},
  pages={253-258}
}
The anterior part of the preoptic nucleus (APON) in anurans is considered to be a center for mate calling. This locus makes an anatomical complex with the amygdala pars medialis (Am). The nuclear volumes of the Am and APON in the male toad are significantly larger than those in the female. In addition, the nuclear volumes of these loci in the hibernating male are larger than those in the post-breeding animal. These results suggest that the Am-APON complex has an important role in male sexual… Expand
Effects of castration on volumes of the preoptic nucleus and the amygdala and on immunoreactivity of LH-RH fibers in the brain of the toad, Bufo japonicus.
TLDR
The results suggest that the volumes of sexually dimorphic nuclei, especially Am in the autumn toad, are androgen-dependent, and castration can modulate activity of the extrahypothalamic LH-RH-ergic projection in toad brain. Expand
The Sexually Dimorphic Medial Preoptic Nucleus of Quail: A Key Brain Area Mediating Steroid Action on Male Sexual Behavior
TLDR
The quail POM constitutes an exceptional model for the analysis of steroid-induced brain plasticity in a functionally relevant context and appears to be a key target for steroids in the activation of male copulatory behavior. Expand
Sexual dimorphism in the preoptic/anterior hypothalamic area of ferrets: Effects of adult exposure to sex steroids
TLDR
The sex difference in cellular organization observed in the ferret at the junction of thePOA and AH is the first difference of this type to be seen in the POA/AH of a non-rodent mammalian species and will aid in the analysis of the neural mechanisms that control various sex-specific behaviors in this species. Expand
Effects of testosterone on a selected neuronal population within the preoptic sexually dimorphic nucleus of the Japanese quail
TLDR
The effects of testosterone on the volume and cytoarchitecture of the sexually dimorphic nucleus of the preoptic area (POM) were investigated in male and female Japanese quail and it was confirmed that castration decreases the POM volume in males and that testosterone increases this volume to values similar to those observed in intact sexually mature males. Expand
The human medial amygdaloid nucleus: No evidence for sex difference in volume
  • G. Murphy
  • Psychology, Medicine
  • Brain Research
  • 1986
TLDR
The volume of the medial nucleus of the amygdala was determined in the right and in the left hemispheres in 17 human brains and an analysis of covariance showed no significant sexual dimorphism in medial nucleus volume. Expand
Effects of lesions of a sexually dimorphic nucleus in the preoptic/anterior hypothalamic area on the expression of androgen- and estrogen-dependent sexual behaviors in male ferrets
TLDR
The results suggest that the MN-POA/AH of the male ferret exerts an inhibitory influence on estrogen-dependent proceptive responsiveness, but play only a minor role in the control of masculine coital behavior. Expand
The afferent projections to the anterior part of the preoptic nucleus in Japanese toads, Bufo japonicus
The afferent innervations of the anterior part of the preoptic nucleus (APON), which is a presumed center for triggering reproductive behavior in anuran amphibians, were studied by use of aExpand
Projections of luteinizing hormone-releasing hormone and vasotocin fibers to the anterior part of the preoptic nucleus in the toad, Bufo japonicus.
TLDR
Observations indicate that the LH-RH and vasotocin fibers may form ordinary and/or en passant synapses with the APON neurons to transmit peptidergic neuronal signals which are concerned with initiation of seasonal reproductive behavior. Expand
Co-localization of mesotocin and opsin immunoreactivity in the hypothalamic preoptic nucleus of Xenopus laevis
TLDR
There is the first strong evidence that the hypothalamic mesotocinergic neurons, which have been proved to be connected to the GnRH system in other species, are directly involved in photoreception in Xenopus laevis, a novel contribution to the understanding of how light influences the seasonal reproductive cycles in lower vertebrates. Expand
Sexual dimorphism in the vasotocin system of the bullfrog (Rana catesbeiana)
TLDR
Since the areas that showed sex differences in AVT distribution have also been implicated in control of reproductive behaviors, they may form the neural substrates for the effects of AVT on sexually dimorphic behaviors in amphibians. Expand
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