Calcagnetti D J, Quatrella L A, Schechter M D
Department of Pharmacology, Northeastern Ohio Universities College of Medicine, Rootstown 44272-0095, USA.
Physiol Behav. 1996 Apr-May;59(4-5):597-604. doi: 10.1016/0031-9384(95)02119-1.
The role of the olfactory sense in the expression of cocaine-induced conditioned place preference (CPP) was examined in adult male rats (n = 35) of the N/Nih strain. Consistent with the scientific literature, rats were observed to significantly (p < 0.05) increase (double) the seconds spent in their least-preferred chamber following cocaine-chamber pairings. Subsequently, groups of rats underwent one of three treatments: 1) olfactory bulbectomy (BULBX), 2) sham surgery (SHAM), or 3) sham surgery plus intranasal zinc sulfate perfusion (ZnSO4). Zinc sulfate was used to produce a temporary loss of olfaction. In a separate behavioral measure of olfactory acuity, both BULBX and ZnSO4-treated rats performed at an equally deficient level, in contrast to SHAM-treated rats that were not rendered anosmic. A second conditioned place preference test revealed that the ZnSO4-perfused and SHAM groups did not differ from their original postcocaine preference measurements. In contrast, the BULBX group spent significantly fewer seconds in the cocaine-paired chamber. After a 14-day interval, a third preference test revealed that SHAM and ZnSO4-treated rats displayed an equivalent preference for the cocaine-paired chamber (at 2.7 times above baseline). Interestingly, the seconds spent in the cocaine-paired chamber by BULBX rats did not differ from their baseline (e.g., precocaine exposure). These results suggest that bulbectomy disrupts the expression of cocaine-induced place preference. Interpretations of data from BULBX rats involving the production of an anhedonic condition and the relevance of olfactory bulbectomy as an animal model of anhedonic depression are discussed.
在N/Nih品系的成年雄性大鼠（n = 35）中，研究了嗅觉在可卡因诱导的条件性位置偏爱（CPP）表达中的作用。与科学文献一致，观察到大鼠在可卡因与特定腔室配对后，在其最不喜欢的腔室中停留的时间显著增加（翻倍）（p < 0.05）。随后，将大鼠分为三组进行以下三种处理之一：1）嗅球切除术（BULBX）；2）假手术（SHAM）；3）假手术加鼻内硫酸锌灌注（ZnSO4）。硫酸锌用于导致暂时嗅觉丧失。在一项单独的嗅觉敏锐度行为测量中，与未致嗅觉缺失的假手术组大鼠相比，接受嗅球切除术和硫酸锌处理的大鼠表现出同样程度的缺陷。第二次条件性位置偏爱测试显示，硫酸锌灌注组和假手术组与它们最初的可卡因偏爱测量结果没有差异。相比之下，嗅球切除组在与可卡因配对的腔室中停留的时间显著减少。间隔14天后，第三次偏爱测试显示，假手术组和硫酸锌处理组大鼠对与可卡因配对的腔室表现出同等的偏爱（比基线高2.7倍）。有趣的是，嗅球切除组大鼠在与可卡因配对的腔室中停留的时间与它们的基线（例如，可卡因暴露前）没有差异。这些结果表明，嗅球切除术会破坏可卡因诱导的位置偏爱的表达。讨论了来自嗅球切除组大鼠的数据解释，涉及快感缺失状态的产生以及嗅球切除术作为快感缺失性抑郁症动物模型的相关性。
