OBJECTIVETo investigate the effects of androgen on sexually dimorphism nucleus in preoptic area (SDN-POA) and anteroventral periventricular nucleus (AVPV) before sexual differentiation of the brain in female rats.

METHODSNeonatal female SD rats (n=12) were randomly divided into two groups: androgen group and control group. Twenty-four hours after birth animals were subjected to intraperitoneal injection of 50 microl of testosterone propionate (TP,10.0 g/L) or aseptic oil as control. The rats were sacrificed 60 days after the injection and the brains were collected for crystal violet staining. LEICA Q Win system was applied in detecting the boundaries of SDN-POA and AVPV, then the volumes of SDN-POA and AVPV were calculated.

RESULTSThe volumes of SDN-POA in androgen group were significantly larger than those in control group [(16.77+/-2.68) vs (8.99+/-1.42)mm(3)x10(-3), P<0.01], while the volumes of AVPV in androgen group were significantly smaller than those in control group [(9.14+/-1.16) vs (14.62+/-2.80)mm(3)x10(-3), P<0.01].

CONCLUSIONExogenous androgen rendered before sexual differentiation in female rats results in enlargement of SDN-POA volumes and reduction of AVPV.

Androgens ; pharmacology ; Animals ; Animals, Newborn ; Female ; Paraventricular Hypothalamic Nucleus ; anatomy & histology ; drug effects ; Preoptic Area ; anatomy & histology ; drug effects ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Sex Differentiation

Organotypic slice cultures have been developed as an alternative to acute brain slices because the neuronal viability and synaptic connectivity in these cultures can be preserved well for a prolonged period of time. This study evaluated a stationary organotypic slice culture developed for the hypothalamic paraventricular nucleus (PVN) of rat. The results showed that the slice cultures maintain the typical shape of the nucleus, the immunocytochemical signals for oxytocin, vasopressin, and corticotropin-releasing hormone, and the electrophysiological properties of PVN neurons for up to 3 weeks in vitro. The PVN neurons in the culture expressed the green fluorescent protein gene that had been delivered by the adenoviral vectors. The results indicate that the cultured slices preserve the properties of the PVN neurons, and can be used in longterm studies on these neurons in vitro.
Adenoviridae ; Animals ; Cell Culture Techniques/*methods ; Corticotropin-Releasing Hormone/metabolism ; Electrophysiology ; Genetic Vectors ; Green Fluorescent Proteins/metabolism ; Immunohistochemistry ; Neurons/*cytology/metabolism ; Oxazines ; Oxytocin/metabolism ; Paraventricular Hypothalamic Nucleus/*anatomy & histology/cytology/metabolism ; Rats ; Vasopressins/metabolism