Carbo-Gas Maria, Vazquez-Sanroman Dolores, Gil-Miravet Isis, De las Heras-Chanes Joan, Coria-Avila Genaro A, Manzo Jorge, Sanchis-Segura Carla, Miquel Marta
Área de Psicobiología, Universitat Jaume I, Castellon de la Plana, Spain.
Centro de Investigaciones Cerebrales, Universidad Veracruzana, Xalapa, Mexico.
Physiol Behav. 2014 Jun 10;132:24-35. doi: 10.1016/j.physbeh.2014.04.044. Epub 2014 May 9.
Pavlovian conditioning tunes the motivational drive of drug-associated stimuli, fostering the probability of those environmental stimuli to promote and trigger drug seeking and taking. Interestingly, different areas in the cerebellum are involved in the formation and long-lasting storage of Pavlovian emotional memory. Very recently, we have shown that conditioned preference for an odour associated with cocaine was directly correlated with cFOS expression in cells at the dorsal region of the granule cell layer of the cerebellar vermis. The main goal of the current investigation was to further extend the description of cFOS-IR patterns in cerebellar circuitry after training mice in a cocaine-odour Pavlovian conditioning procedure, including now the major inputs (the inferior olive and pontine nuclei) and one of the output nuclei (the medial deep nucleus) of the cerebellum. The results showed that the cerebellar hallmark of preference towards an odour cue associated to cocaine is an increase in cFOS expression in the dorsal part of the granule cell layer. cFOS-IR levels expressed in the granule cell layer of mice that did not show cocaine conditioned preference did not differ from the basal levels. Remarkably, mice subjected to a random cocaine-odour pairing procedure (the unpaired group) exhibited higher cFOS-IR in the inferior olive, the pontine nuclei and in the deep medial nucleus. Therefore, our findings suggest that inputs and the output of cerebellar circuitry are enhanced when contingency between the CS+ and cocaine is lacking.
经典条件作用调节与药物相关刺激的动机驱力，增加了这些环境刺激促进和引发觅药与用药行为的可能性。有趣的是，小脑的不同区域参与了经典条件性情绪记忆的形成和长期存储。最近，我们发现对与可卡因相关气味的条件性偏好与小脑蚓部颗粒细胞层背侧区域细胞中的cFOS表达直接相关。本研究的主要目的是在对小鼠进行可卡因-气味经典条件作用训练后，进一步扩展对小脑回路中cFOS免疫反应模式的描述，现在包括小脑的主要输入（下橄榄核和脑桥核）和一个输出核（内侧深核）。结果表明，对与可卡因相关气味线索偏好的小脑特征是颗粒细胞层背侧部分cFOS表达增加。未表现出可卡因条件性偏好的小鼠颗粒细胞层中表达的cFOS免疫反应水平与基础水平无差异。值得注意的是，接受随机可卡因-气味配对程序（未配对组）的小鼠在下橄榄核、脑桥核和内侧深核中表现出更高的cFOS免疫反应。因此，我们的研究结果表明，当条件刺激（CS+）与可卡因之间缺乏关联性时，小脑回路的输入和输出会增强。
