Hwang Bang H, Suzuki Ryoji, Lumeng Lawrence, Li T-K, McBride William J
Department of Anatomy and Cell Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA.
Neuropeptides. 2004 Dec;38(6):359-68. doi: 10.1016/j.npep.2004.09.004.
The neuropeptide Y (NPY) gene in rat chromosome 4 has been shown to play an important role in alcohol-seeking behavior. NPY knockout mice drink more alcohol than wild-type mice, implicating a link between NPY deficiency and high alcohol intake. This is supported by recent studies showing that intracerebroventricular injections of NPY reduce alcohol intake in both alcohol-preferring (P) and high alcohol-drinking rats. However, it is unknown which anatomical NPY systems are involved in alcohol preference. This study was designed to investigate whether there are innate differences in NPY mRNA in cerebral cortical areas, dentate gyrus (DG) of the hippocampus and medial habenular nucleus (MHb) between P and alcohol-nonpreferring (NP) rats, as these discrete brain regions are rich in NPY mRNA. [(33)P]-labeled 28-mer oligodeoxynucleotide probe was applied for the in situ hybridization study to detect the NPY mRNA, measured using quantitative autoradiography. This study revealed an absence of NPY mRNA in the MHb of P rats. We found that NPY mRNA was significantly lower in the DG of P rats than NP rats. This innate difference of NPY mRNA expression in the DG between P and NP rats is region specific. For example, in most of the cerebral cortical areas examined, an innate difference was not seen. Our study suggests that lower NPY gene expression in the DG and MHb of P rats may be factors contributing to some of the phenotypic differences observed between the P and NP lines of rats.
大鼠4号染色体上的神经肽Y（NPY）基因已被证明在觅酒行为中起重要作用。NPY基因敲除小鼠比野生型小鼠饮酒更多，这表明NPY缺乏与高酒精摄入量之间存在联系。最近的研究支持了这一点，这些研究表明，脑室内注射NPY可减少嗜酒（P）和高饮酒量大鼠的酒精摄入量。然而，尚不清楚哪些解剖学上的NPY系统与酒精偏好有关。本研究旨在调查P大鼠和非嗜酒（NP）大鼠的大脑皮质区域、海马齿状回（DG）和内侧缰核（MHb）中NPY mRNA是否存在先天差异，因为这些离散的脑区富含NPY mRNA。使用[（33）P]标记的28聚体寡脱氧核苷酸探针进行原位杂交研究以检测NPY mRNA，采用定量放射自显影法进行测量。本研究发现P大鼠的MHb中不存在NPY mRNA。我们发现P大鼠DG中的NPY mRNA明显低于NP大鼠。P大鼠和NP大鼠在DG中NPY mRNA表达的这种先天差异具有区域特异性。例如，在大多数检查的大脑皮质区域中，未观察到先天差异。我们的研究表明，P大鼠DG和MHb中较低的NPY基因表达可能是导致P大鼠和NP大鼠品系之间观察到的一些表型差异的因素。
