Center for Development and Behavioral Neuroscience, Department of Psychology, Binghamton University PO Box 6000, Binghamton, NY 13902-6000, United States.
Behav Brain Res. 2013 Mar 1;240:69-75. doi: 10.1016/j.bbr.2012.11.020. Epub 2012 Nov 26.
We have previously demonstrated that gonadectomy either prior to (early) or after (late) puberty elevated ethanol consumption in males to levels similar to intact adult females-effects that were attenuated by testosterone replacement. To assess whether alterations in the aversive effects of ethanol might contribute to gonadectomy-associated increases in ethanol intake in males, the present study examined the impact of gonadectomy on conditioned taste aversions (CTA) to ethanol in male and female Sprague-Dawley rats. Animals were gonadectomized, received sham surgery (SH) or non-manipulated (NM) on postnatal (P) day 23 (early) or 67 (late) and tested for CTA to ethanol in adulthood. Water-deprived rats were given 1 hr access every-other-day to 10% sucrose followed by an injection of ethanol (0, 1g/kg) for 5 test sessions. Test data were analyzed to determine the first day significant aversions emerged in each ethanol group (i.e., sucrose intakes significantly less than their saline-injected counterparts). Early gonadectomized males acquired the CTA more rapidly than did early SH and NM males (day 1 vs 3 and 4 respectively), whereas a gonadectomy-associated enhancement in ethanol CTA was not evident in late males. Among females, gonadectomy had little impact on ethanol-induced CTA, with females in all groups showing an aversion by the first or second day, regardless of surgery age. These data suggest that previously observed elevations in ethanol intake induced by either pre- or post-pubertal gonadectomy in males are not related simply to gonadectomy-induced alterations in the aversive effects of ethanol indexed via CTA.
我们之前的研究表明,无论是在青春期前(早期)还是青春期后(晚期)进行性腺切除术都会使雄性的乙醇摄入量增加到与未被手术的成年雌性相似的水平,而这种效果会被睾酮替代所减弱。为了评估乙醇的厌恶效应改变是否会导致性腺切除术后雄性乙醇摄入量增加,本研究在雄性和雌性 Sprague-Dawley 大鼠中研究了性腺切除对乙醇条件性味觉厌恶(CTA)的影响。动物在出生后第 23 天(早期)或第 67 天(晚期)进行性腺切除术、假手术(SH)或非手术(NM)处理,并在成年期进行乙醇 CTA 测试。缺水的大鼠每两天接受一次 1 小时的 10%蔗糖溶液,然后注射 0、1g/kg 的乙醇,共进行 5 次测试。通过分析测试数据,确定每个乙醇组中首次出现显著厌恶的天数(即,摄入的蔗糖量明显低于其生理盐水注射对照组)。早期性腺切除的雄性比早期 SH 和 NM 雄性更快地获得 CTA(第 1 天与第 3 天和第 4 天相比),而晚期雄性的乙醇 CTA 并没有出现性腺切除增强的现象。在雌性中,性腺切除对乙醇引起的 CTA 影响不大,所有组别的雌性在第 1 天或第 2 天就表现出厌恶,而不论手术年龄如何。这些数据表明,之前观察到的雄性在青春期前或青春期后进行性腺切除会导致乙醇摄入量增加,这并不是简单地归因于性腺切除引起的乙醇厌恶效应改变,这种改变通过 CTA 进行了评估。