DIFFERENTIAL GENE EXPRESSION & TOLERANCE TO CANNABINOIDS

大麻素（δ 9-THC）的长期给药导致异常 l生理和行为功能恢复到 接近正常（对照）水平，但重要的第二信使途径仍然改变 了解参与发展的细胞机制， 对慢性大麻素治疗的耐受性将使我们深入了解 负责耐受其他经常管理或滥用药物。 对这些过程的调查可以从实施新的 快速检查可能改变的表达谱的策略， 大量的基因，以确定那些可能参与 产生耐受性。使用大规模cDNA微阵列的初步数据 筛选技术显示，大量的基因相关， 大麻素系统功能的各个方面显示出改变的表达， 在21天的治疗期内的模式。这些模式在两个方面进行了评估 不同的大脑区域，海马和小脑，并揭示了相似的时间 大麻素（CB 1）受体和第二信使信号传导改变的过程。 据推测，共同的系统和它们各自的分子对应物 可能参与对慢性药物暴露的适应，但这可能在特定的大脑区域和特定的细胞类型中有所不同。我们建议调整和扩大cDNA的使用 微阵列，以进一步描绘改变基因表达的变化， 长期接触大麻素具体目标1将描述 在这些和其他3个大脑区域的差异基因表达模式， 在慢性大麻素治疗期间的不同时间点（即天数）。 具体目标2将通过评估以下方面的变化进一步分析： 慢性戒断过程中的基因表达谱 大麻素暴露具体目标3将评估特定的大脑区域， 这些基因表达的变化发生利用原位杂交， 确定基因的区域和细胞分布，所述基因的表达是 在慢性暴露期间和突然戒断期间的变化（特定 目标1和2）。

Chronic administration of cannabinoids (delta 9-THC) result in an unusua l degree of tolerance in which physiological and behavioral functions revert to near normal (control) levels but important second messenger pathways remain altered Understanding of the cellular mechanisms involved in the development of tolerance to chronic cannabinoid treatment will provide insight into processes responsible for tolerance to other frequently administered or abused drugs. Investigation of these processes can benefit from implementation of new strategies to quickly examine potentially altered expression profiles across large numbers of genes in order to determine those that might be involved in producing tolerance. Preliminary data using large scale cDNA microarray screening technology revealed that a significant number of genes related to various aspects of cannabinoid system function showed altered expression patterns across a 21 day treatment period. These patterns were assessed in two different brain regions, hippocampus and cerebellum and revealed similar time courses to cannabinoid (CBl) receptor and second messenger signaling changes. It is hypothesized that, common systems and their respective molecular counterparts may participate in adaptation to chronic drug exposure but this may differ across particular brain regions specific cell types. We propose to adapt and extend use of cDNA microarrays to delineate further the changes in altered gene expression during chronic exposure to cannabinoids. Specific Aim 1 will characterize the differential gene expression patterns in these and 3 other brain regions at different time points (i.e. days) during chronic cannabinoid treatment. Specific Aim 2 will take the analysis one step further by assessing changes in gene expression profiles during precipitated withdrawal from chronic cannabinoid exposure. Specific Aim 3 will assess the specific brain regions in which these gene expression changes occur utilizing in situ hybridization to determine the regional and cellular distribution of genes whose expression is changed during chronic exposure and during precipitated withdrawal (Specific Aims 1 and 2).