Sexually dimorphic contribution from the fornix to the ventromedial hypothalamic nucleus: a quantitative electron microscopic study
| Autor: | Mariano Ramírez-Degollado, Jorge Larriva-Sahd, Adrián Rondán-Zárate |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Male
medicine.medical_specialty Central nervous system Biology chemistry.chemical_compound Pregnancy Internal medicine medicine Neuropil Animals Neurons Sex Characteristics General Neuroscience Fornix Rats Sexual dimorphism Microscopy Electron Endocrinology Castration medicine.anatomical_structure chemistry Ventromedial Hypothalamic Nucleus Hypothalamus Nerve Degeneration Synapses Ventromedial hypothalamic nucleus Female Orchiectomy Hormone |
| Zdroj: | Neuroscience Letters. 200:147-150 |
| ISSN: | 0304-3940 |
| DOI: | 10.1016/0304-3940(95)12129-r |
| Popis: | Quantitative electron microscopy confirmed that the neuropil of the ventrolateral part of the ventromedial hypothalamic nucleus (VL-VMHN) of the rat is sexually dimorphic with respect to the density of shaft and axo-spinous synapses, both of which are more numerous in the male. In addition, adult rats with complete interruption of the fornix displayed a sexually dimorphic input in the density of fornical synapses in the neuropil of the VL-VMHN, in which degenerating terminals were more numerous in the male. Perinatal exposure of the female to exogenous testosterone or castration of the newborn male ‘inverted’ these sex differences, demonstrating their hormonal dependence. It is concluded that (1) the fornix provides synaptic input to the VL-VMHN as proven by orthograde degeneration; (2) the number of fornical endings synapsing in the VL-VMHN is greater in the male than in the female; (3) this dimorphism depends of the organizational effect of gonadal sex steroids. |
| Databáze: | OpenAIRE |
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