Spinophilin function in regulating pathological responses to psychostimulant drug

大脑由许多不同类型的神经元组成。例如，纹状体中的一类神经元被称为中棘神经元（MSN）。这些多刺神经元之所以被称为多刺神经元，是因为它们含有树突棘，这些树突棘与来自皮质的含谷氨酸的轴突和来自黑质的含多巴胺的轴突形成连接，称为突触。MSNs上的树突棘在称为突触后密度的电子致密区包含信号和支架分子。滥用精神兴奋剂药物的作用是增加黑质多巴胺能神经元的多巴胺释放，这对定位于MSN树棘的蛋白质具有下游影响。一种蛋白质，spinophilin，在长期暴露于滥用的精神兴奋剂药物时增加。纹状体MSNs可以分为两类，直接和间接通路神经元。目前，很少有方法来评估突触蛋白在不同类别的MSN中的功能。这一点很重要，因为这两类MSN对精神兴奋剂暴露有不同的反应。我们的建议的目标是确定在两个类的MSN在调节慢性无毒和有毒的精神兴奋剂，如可卡因和安非他明的方案的反应spinophilin功能。确定细胞特异性作用的spinophilin介导的病理与这些药物的滥用将确定新的途径，可以有针对性地治疗成瘾和长期甲基苯丙胺滥用相关的疾病，如帕金森病（PD）。在这个提议中，我们假设，亲棘素在两个MSN人群中起着独特的作用，在介导精神兴奋剂诱导的病理。这一假设将使用以下具体目标进行检验：目标1。（R21）。生成并验证在直接和间接途径MSN中表达他莫昔芬诱导型iCre的小鼠品系。我们将产生在直接或间接途径MSN中表达他莫昔芬诱导型改良Cre（iCre）重组酶的小鼠品系。 目标2.（R21）。生成并验证floxed spinophilin（Spinofl/fl）小鼠。我们将产生一种新的转基因小鼠系，其将与目标1中产生的iCre动物杂交以产生MSN特异性亲棘蛋白KO动物。 目标3.（R33）。确定亲棘素在直接和间接途径MSNs对精神兴奋剂致敏中的作用。我们将使用目标1和2中创建的小鼠来确定两个MSN群体中的亲棘素对与精神兴奋剂诱导的致敏相关的病理的调节的功能。（R33）。确定亲棘素在METH毒性的直接和间接途径MSN中的作用。我们将使用目标1和2中创建的小鼠来确定两个MSN群体中的亲棘素对与甲基苯丙胺诱导的毒性相关的病理学的调节的功能。

The brain is made up of many different types of neurons. For example, one class of neuron in the striatum is called the medium spiny neuron (MSN). These spiny neurons are so called because they contain dendritic spines that form connections, called synapses, with glutamate-containing axons from the cortex and dopamine containing axons from the substantia nigra. The dendritic spines on the MSNs contain signaling and scaffolding molecules in an electron dense area called the postsynaptic density. Psychostimulant drugs of abuse act to increase dopamine release from nigral dopaminergic neurons, which has downstream effects on proteins that are localized to MSN dendritic spines. One protein, spinophilin, is increased upon chronic exposure to psychostimulant drugs of abuse. Striatal MSNs can be subdivided into two classes, direct and indirect pathway neurons. Currently there are very few ways to evaluate the function of synaptic proteins in the different classes of MSNs. This is important because the two classes of MSNs have different responses to psychostimulant exposure. The goal of our proposal is to determine the function of spinophilin in the two classes of MSNs in regulating responses to chronic non-toxic and toxic regimens of psychomotor stimulants such as cocaine and amphetamines. Determining the cell-specific role of spinophilin in mediating pathologies associated with these drugs of abuse will identify new pathways that can be targeted for treatment of addiction and disorders associated with long-term methamphetamine abuse, such as Parkinson disease (PD). In this proposal, we hypothesize that spinophilin plays a unique role in the two MSN populations in mediating psychostimulant-induced pathologies. This hypothesis will be tested using the following specific aims: Aim 1. (R21). Generate and validate mouse lines expressing tamoxifen-inducible, iCre in direct and indirect pathway MSNs. We will generate mouse lines that express a tamoxifen-inducible, improved Cre (iCre) recombinase in direct or indirect pathway MSNs. Aim 2. (R21). Generate and validate floxed spinophilin (Spinofl/fl) mice. We will generate a novel transgenic mouse line that will be crossed with the iCre animals generated in aim 1 to create MSN-specific spinophilin KO animals. Aim 3. (R33). Determine the role of spinophilin in direct and indirect pathway MSNs on psychostimulant sensitization. We will use mice created in aims 1 and 2 to determine the function of spinophilin in the two MSN populations on the regulation of pathologies associated with psychostimulant-induced sensitization Aim 4. (R33). Determine the role of spinophilin in direct and indirect pathway MSNs on METH toxicity. We will use mice created in aims 1 and 2 to determine the function of spinophilin in the two MSN populations on the regulation of pathologies associated with methamphetamine-induced toxicity.