Identification of GPR55 cellular expression within hippocampal cells and its phys

描述（由申请人提供）：海马体是大脑中调节学习和记忆的区域。海马体功能障碍，包括阿尔茨海默病和癫痫，是一个严重的健康问题，扰乱了人们的生活，造成了数百万美元的损失。最近，内源性大麻素（eCBs）被认为是治疗阿尔茨海默病的候选药物，对疾病的演变和缓解症状有有益的影响。此外，eCB是抗癫痫发生的极佳靶点，因为eCB受体通常位于突触前，可减少兴奋性递质释放，从而减轻兴奋性癫痫发作活动。海马学习记忆的细胞过程是突触可塑性。突触可塑性或突触活动的变化发生在对来自感官的传入输入的反应中，使我们能够对环境的变化和经历做出反应和适应。目前，几种重要的通路被证明在调节可塑性中起作用，包括eCB和eCB受体。大脑中主要的eCB受体是大麻素受体1 （CB1）。例如，当被大麻中的活性成分四氢大麻酚激活时，这种受体会通过降低可塑性来损害记忆。虽然许多人已经研究了CB1对突触可塑性的影响，但还有其他参与可塑性的eCB通路/受体未被CB1所解释。这些描述被描述为来自“非CB1”或未识别的CB3受体，因为涉及CB1（而不是CB2）。然而，这种“非cb1”受体（可能是一个或多个受体）并没有与特定的受体类型相关。为了充分理解“非cb1”受体如何影响海马体的可塑性，从而影响学习和记忆，我们必须首先确定这种受体是什么。这种受体的一个极好的候选者是尚未分类的孤儿G蛋白受体GPR55，因为它在大脑中表达并且功能活跃。重要的是，GPR55结合了像anandamide这样的eCBs。本研究计划的主要目的是研究GPR55和相关受体作为海马eCB受体调节海马可塑性，从而形成记忆。我们将首先使用定量实时PCR和免疫细胞化学检测海马GPR55 mRNA和蛋白的细胞表达。然后，利用全细胞和场电生理学，我们将研究GPR55参与兴奋性突触传递的调节和改变海马突触可塑性，即长期增强。该项目的长期目标是更好地了解eCB，特别是新型eCB受体在调节海马功能和可塑性方面的作用，以减轻海马病理状态相关的一些并发症，包括阿尔茨海默病和癫痫。

DESCRIPTION (provided by applicant): The hippocampus is the brain region mediating learning and memory. Hippocampal dysfunction disorders, which include Alzheimer's disease and epilepsy, are a significant health problem disrupting life and costing millions of dollars. Recently, endocannabinoids (eCBs) were suggested as candidates to treat Alzheimer's disease for beneficial effects on the evolution of the disease and alleviating symptoms. In addition, eCBs are an excellent target for antiepileptogenesis because eCB receptors are often presynaptic and decrease excitatory transmitter release thus mitigating excitatory seizure activity. The cellular process of hippocampal learning and memory is synaptic plasticity. Synaptic plasticity or changes in synaptic activity occur in response to afferent input from our senses, allowing for us to respond and adapt to changes and experiences in our environment. Currently, several important pathways were demonstrated to play a role in modulating plasticity, including eCBs and eCB receptors. The primary eCB receptor in the brain is cannabinoid receptor 1 (CB1). This receptor for example impairs memory by decreasing plasticity when activated by THC, the active component in marijuana. While many have studied the effect of CB1 on synaptic plasticity, there are other eCB pathways/receptors involved in plasticity not accounted for by CB1. These accounts were described as being from a 'non-CB1' or unidentified CB3 receptor because CB1 (nor CB2) was involved. However, this 'non-CB1' receptor (possibly one or more receptors) has not been correlated to a particular receptor type. In order to fully understand how a 'non-CB1' receptor is influencing hippocampal plasticity and thus learning and memory, we must first identify what this receptor is. One excellent candidate for this receptor is the yet to e classified orphan G protein receptor, GPR55, because it is expressed in the brain and is functionally active. Importantly, GPR55 binds eCBs such as anandamide. The main goal of this research proposal is to investigate GPR55 and related receptors as putative hippocampal eCB receptors that modulate hippocampal plasticity, and thus memory formation. We will first use quantitative real-time PCR and immunocytochemistry to examine cellular expression of hippocampal GPR55 mRNA and protein. Then using whole cell and field electrophysiology we will examine the involvement of GPR55 in modulation of excitatory synaptic transmission and altering hippocampal synaptic plasticity, namely long-term potentiation. The broad long-term goals of this project are to better understand the role eCBs, especially novel eCB receptors, play in modulating hippocampal function and plasticity with a view towards alleviating some of the complications associated with pathologic states in the hippocampus including Alzheimer's disease and epilepsy. PUBLIC HEALTH RELEVANCE: Alzheimer's and epilepsy are disease states that occur in the hippocampus, the brain region involved in learning and memory, which is mediated by synaptic plasticity, critical for memory. Endocannabinoids modulate hippocampal synaptic plasticity and therefore memory as well as epilepsy, however, many endocannabinoid pathways exist in the hippocampus have not been identified. Our goal is to investigate a novel receptor we believe to be involved in endocannabinoid- mediated modulation of synaptic plasticity with a view towards applying what we learn towards alleviating deficits in disease states such as Alzheimer's and epilepsy.