Aloisi A M, Albonetti M E, Carli G
Istituto Fisiologia Umana, Università degli Studi di Siena, Italy.
Neuroscience. 1996 Oct;74(4):1019-24. doi: 10.1016/0306-4522(96)00232-1.
Formalin (10%) induces higher levels of licking and flexing in female than in male rats, as shown in the present study. In order to ascertain the neural and hormonal modifications that accompany these behavioural differences, we determined the activity of choline acetyltransferase in the hippocampus and the levels of adrenocorticotropic hormone and corticosterone in the plasma. Two concentrations of formalin were used (50 microliters; 0.1% or 10%). Formalin was injected subcutaneously in the dorsal part of the hindpaw, and the animal's behaviour was then recorded for 60 min in a familiar open-field apparatus. Hippocampal choline acetyltransferase activity did not differ between the two genders in controls, while a significant gender difference was present in both formalin-injected groups, with higher levels in females than in males. This was the result of a decrease in males but not in females. In contrast, adrenocorticotropic hormone was increased by both formalin concentrations in females; corticosterone was not affected by treatment in either gender. Results are discussed in the light of the morphological and functional differences between the two genders in the hippocampus and in the hypothalamo-pituitary-adrenal axis.
如本研究所示，福尔马林（10%）诱导雌性大鼠出现比雄性大鼠更高水平的舔舐和屈曲行为。为了确定伴随这些行为差异的神经和激素变化，我们测定了海马中胆碱乙酰转移酶的活性以及血浆中促肾上腺皮质激素和皮质酮的水平。使用了两种浓度的福尔马林（50微升；0.1%或10%）。将福尔马林皮下注射到后爪背部，然后在熟悉的旷场装置中记录动物60分钟的行为。对照组中，两性的海马胆碱乙酰转移酶活性没有差异，而在两个注射福尔马林的组中均存在显著的性别差异，雌性水平高于雄性。这是由于雄性而非雌性的该酶活性降低所致。相反，两种浓度的福尔马林均使雌性大鼠的促肾上腺皮质激素增加；皮质酮水平在两性中均未受处理影响。根据海马以及下丘脑-垂体-肾上腺轴中两性之间的形态学和功能差异对结果进行了讨论。
