Neuroendocrinology and Neuroimmunology
Author: Rocio del Milagro Bigarani | Email: rbigarani@immf.uncor.edu
Rocio del Milagro Bigarani1°, Maria Julia Cambiasso1°2°, Carla Daniela Cisternas1°3°
1° Instituto de Investigación Médica M y M Ferreyra, INIMEC-CONICET-UNC, Córdoba, Argentina.
2° Cátedra de Biología Celular, Facultad de Odontología, Universidad Nacional de Córdoba, Argentina
3° Cátedra de Fisiología Animal, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Argentina
Sex differences in neurochemical cell phenotype might have broad consequences and underlie differences in neuronal function, morphology, connectivity, and neurotransmitter production in males and females. Many of these sex dimorphisms in the brain are organized during development by gonadal hormones and by a sex-specific genetic and epigenetic pattern. We previously found sex differences in brain expression of enzymes involved in DNA methylation and demethylation that were restricted to the critical period of sexual differentiation. Here, we explored oxytocin (OXT) expression in the preoptic area (POA), the paraventricular (PVN) and supraoptic (SON) nucleus of the hypothalamus by immunohistochemistry at postnatal day (P) 7 and P18 in male and female mice. We found a higher number of OXT+ neurons and covered area by OXT-immunoreactivity (p<0.05) in the female POA at P18. We also studied oxytocin receptor (OXTR) expression by qPCR in brain punches of prefrontal cortex (PFC), POA and the PVN at the same postnatal ages. At P7, we found a higher expression of OXTR (p<0.01) in the PFC of males compared with females. No sex differences were found in the PVN and SON at P7 or P18. Taken together with our previous results, these sex differences in oxytocinergic regions during development might be mediated by a sex-specific regulation of epigenetic mechanisms during the critical period of sexual differentiation.