Developmental Alcohol exposure and cerebro-cerebellar circuits

项目摘要/摘要 认知和执行功能缺陷是胎儿最严重的后果之一 酒精暴露。目前针对这些缺陷的现有治疗方法效果有限。我们的 长期目标是确定认知缺陷背后的特定功能机制 与FASD相关。我们的目标是使用电路追踪和切片电生理学来确定 妊娠晚期当量酒精暴露(TTAE)对大脑皮层各成分的长期影响 大脑-小脑系统参与执行功能。我们的工作假设是1)TTAE 减少与FASD相关的大脑区域--眶前叶皮质的谷氨酸能输入 执行功能障碍--通过脑桥核神经元和TTAE进入小脑皮质 通过小脑深部减少从小脑到眶前皮质的谷氨酸能输出 核团和丘脑。我们使用电路映射的基本原理是描述TTAE的影响 眶前叶皮质↔小脑相互联系的功能。这一原则证明R21 提案将为R01拨款申请奠定坚实的基础，以延长这项工作。在目标1中， 我们将确定TTAE对大脑-小脑系统前馈功能的影响 四肢。我们将使用顺行跨突触标记、切片电生理学和光遗传学来测试 TTAE持续减少突触谷氨酸能传递的假说 脑桥核神经元(接受眶前皮质的输入)和小脑颗粒细胞 (小叶VI)同时减少桥核神经元→高尔基体区的前馈双突触抑制 细胞→，小脑颗粒，细胞突触。在目标2中，我们将确定TTAE对功能的影响 大脑-小脑系统反馈肢体。我们将使用一种交叉的方法，包括 顺行病毒示踪结合逆转录珠标记法持续检验TTAE假说 减少突触间单突触谷氨酸能和双突触GABA能传递 小脑深核神经元--接受小叶VI--浦肯野神经元的输入--和丘脑 投射到眼眶前额叶皮质的神经元。本申请中提出的研究具有创新性。 因为它将首次系统地表征乙醇对人体发育的影响 大脑-小脑网络的关键组成部分之间的相互作用。拟议的研究是 因为它将阐明新的功能神经生物学机制 酒精暴露导致的执行功能障碍，并确定特定的生物靶点 改善这些赤字的干预措施。

Project Summary / Abstract Cognitive and executive function deficits are among the most devastating consequences of fetal alcohol exposure. Currently available treatments against these deficits have limited efficacy. Our long-term goal is to identify specific functional mechanisms underlying the cognitive deficits associated with FASD. Our objective is to use circuit tracing and slice electrophysiology to determine the long-term impact of third trimester-equivalent alcohol exposure (TTAE) on components of the cerebro-cerebellar system involved in executive function. Our working hypotheses are that 1) TTAE reduces glutamatergic input from the orbitrofrontal cortex—a brain region implicated in FASD-linked executive function deficits—to the cerebellar cortex via pontine nuclei neurons and 2) TTAE decreases glutamatergic output from the cerebellum to the orbitofrontal cortex via the deep cerebellar nuclei and the thalamus. Our rationale for using circuit mapping is to characterize the effects of TTAE on the function of reciprocal orbitofrontal cortex↔cerebellum connections. This proof-of-principle R21 proposal will establish a strong foundation for an R01 grant application to extend this work. In Aim 1, we will determine the effects of TTAE on the function of the cerebro-cerebellar system feed-forward limb. We will use anterograde transsynaptic labeling, slice electrophysiology, and optogenetics to test the hypothesis that TTAE persistently reduces glutamatergic transmission at synapses between pontine nuclei neurons (that receive input from the orbitofrontal cortex) and cerebellar granule cells (lobule VI) while also reducing feed-forward disynaptic inhibition at pontine nuclei neuron→Golgi cell→cerebellar granule cell synapses. In Aim 2, we will determine the effects of TTAE on the function of the cerebro-cerebellar system feedback limb. We will use an intersectional approach consisting of anterograde viral tracing coupled with retrobead labeling to test the hypothesis TTAE persistently reduces monosynaptic glutamatergic and disynaptic GABAergic transmission at synapses between deep cerebellar nuclei neurons—that receive input from lobule VI Purkinje neurons—and thalamic neurons that project to the orbitofrontal cortex. The research proposed in this application is innovative because it will systematically characterize, for the first time, the developmental effects of ethanol on interactions among key components of the cerebro-cerebellar network. The proposed research is significant because it will elucidate novel functional neurobiological mechanisms underlying fetal alcohol exposure-induced executive function deficits, and identify specific biological targets for interventions to ameliorate these deficits.