Identification and characterization of two novel cannabinoid receptors

描述(申请人提供)：到1993年，两种已知的大麻素受体都已被识别出来。从那时起，一个关键的问题一直困扰着大麻素领域：是否只有这些大麻素受体，或者是否还有更多的大麻素受体有待发现？间接证据支持海马体中多达三个额外的“大麻素”受体，但还没有从分子上鉴定出任何受体。如果可以清楚地识别和分离介导非CB1大麻反应的神经元，那么使用现有的技术来识别和克隆受体应该是可能的。克隆一种新的大麻素受体将是大麻素领域的一项重大发展。在研究培养的自体海马神经元(DSE)内大麻素可塑性的过程中，我鉴定了五种兴奋性神经元亚群，其中两种对大麻素表现出明显的反应，即使在没有CB1受体的情况下也是如此。因为自体神经元是孤立的，所以有可能几乎完整地提取整个细胞团。因此，我能够在药理学上鉴定和分离两个神经元亚群的例子，每个亚群都表达一种不同的非CB1大麻受体。该提案的具体目的是：1.使用电生理学方法表征两个神经元亚群中的大麻素样反应。这构成了拟议实验的主要部分，并且在很大程度上独立于(但将大大增强)特定目标#2。2.识别两种新的大麻素受体。这将通过从每个亚群中提取和扩增RNA，然后使用基因阵列和候选基因方法克隆受体来完成。两种新的大麻素受体的发现将对健康产生重大影响。大麻是一种主要的滥用药物，通过大麻素受体发挥作用。了解所有大麻素受体的身份和功能是了解大麻如何影响身体的关键。

DESCRIPTION (provided by applicant): By 1993, both known cannabinoid receptors had been identified. Since then, a key question has hovered over the cannabinoid field: is that all there is or do additional cannabinoid receptors remain to be discovered? Indirect evidence supports as many as three additional 'cannabinoid' receptors in the hippocampus, but no receptors have been molecularly identified. If it were possible to clearly identify and isolate a neuron mediating a non-CB1 cannabinoid response, then it should be possible using existing technologies to identify and clone the receptor. The cloning of a novel cannabinoid receptor would be a major development in the cannabinoid field. In the process of studying endocannabinoid plasticity in cultured autaptic hippocampal neurons (DSE) I have identified five subpopulations of excitatory neurons, two of which exhibit distinct responses to cannabinoids, even in the absence of CB1 receptors. Because autaptic neurons are solitary it is possible to extract the entire cell mass nearly intact. Thus I am in a position to pharmacologically identify and isolate examples of two neuronal subpopulations each expressing a distinct non-CB1 cannabinoid receptor. The specific aims of the proposal are to: 1. Characterize the cannabinoid-like response in both neuronal subpopulations using electrophysiological methods. This constitutes the bulk of proposed experiments and is largely independent of (but would be greatly enhanced by) Specific Aim #2. 2. Identify the two novel cannabinoid receptors. This will be done by extracting and amplifying RNA from each subpopulation, and then cloning the receptor using gene array and candidate gene approaches. Discovery of two new cannabinoid receptors would have considerable health implications. Marijuana is a major drug of abuse, acting via cannabinoid receptors. Knowing the identity and function of all cannabinoid receptors is key to understanding how marijuana affects the body.