8/8 NADIA U01 Long-Term Effects of Adolescent Alcohol on Pain

青少年饮酒会导致持续的神经适应和行为失调， 酒精使用障碍（AUD）。急性酒精可以减轻疼痛，慢性疼痛（例如，痛觉过敏） 可以通过负面的强化镇痛作用促进饮酒。巧合的是，长期酗酒 产生痛觉过敏或使已有的疼痛状态恶化。最近，我们报道内侧中央杏仁核 (CeA)投射到中脑区域称为中脑导水管周围灰质（vlPAG）是至关重要的调解 慢性酒精暴露成年雄性大鼠的痛觉过敏。这种慢性酒精会削弱突触连接 在成年雄性大鼠的内侧CeA和vlPAG之间，CeA-vlPAG回路的光刺激拯救了 在酒精依赖的成年大鼠中，光抑制该回路产生痛觉过敏。 大鼠我们的实验室和其他人发现，CeA中促肾上腺皮质激素释放因子1型受体（CRFR1）的拮抗作用 减少成年大鼠与酒精戒断、尼古丁戒断和创伤应激相关的痛觉过敏。 我们的总体假设是，青春期大鼠慢性间歇性酒精暴露（AIE） 对多模态的持续长期影响（即，机械和热）痛觉过敏，其由减弱的 CeA中的CeA-vlPAG连接性和增加的CRFR1信号传导。CeA-vIPAG的CRFR1信号门控 功能对于介导AIE诱导的痛觉过敏是重要的。 我们包括初步数据表明，1）AIE产生快速和持久的热和机械 在青春期的痛觉过敏，这种影响持续到成年期（图1），2）AIE减少突触 成年期vlPAG投射的内侧CeA神经元上的驱动和兴奋/抑制比（图3），3）CRFR1是 在vlPAG投射细胞上表达（图2），和4）CRFR1：cre大鼠CRFR1+细胞类型的验证数据- CeA输出的特定调制（图4）。因为我们也建议用一种短暂的 在成年期的炎症性疼痛挑战中，我们还试验了角叉菜胶对 成年Wistar大鼠的伤害感受。在这里，我们提出的目标，将测试的假设，AIE生产 在青春期持续到成年期的痛觉过敏（具体目标1），AIE减少了突触驱动 和通过CRFR1 - 1的VIPAG投射的CeA神经元上的突触传递的兴奋/抑制平衡。 依赖性（具体目标2），以及CRFR1+药理学、基于回路的和表观遗传学调节 PAG投射的CeA神经元将拯救AIE诱导的痛觉过敏和CeA-vlPAG回路可塑性（特异性）。 目标3）。重要的是，我们建议与研究组件6（PI：钱德勒）和5（PI： 船员）沿着与表观遗传学核心（PI：潘迪）的NADIA财团。本提案侧重于测试 青少年酒精对疼痛相关结果的影响，并与NADIA联盟的总体目标一致， 研究青少年酒精暴露对成年机体的影响。

Adolescent alcohol use leads to persistent neural adaptations and behavioral dysregulation that increase the risk of developing alcohol use disorder (AUD). Acute alcohol reduces pain, and chronic pain (e.g., hyperalgesia) can promote alcohol drinking through negative reinforcing analgesic effects. Paradoxically, chronic alcohol produces hyperalgesia or worsen pre-existing pain states. Recently, we reported that medial central amygdala (CeA) projections to a midbrain region called the periaqueductal gray (vlPAG) are critical for mediating hyperalgesia in chronically alcohol exposed adult male rats. This chronic alcohol weakens synaptic connectivity between medial CeA and vlPAG in adult male rats, photostimulation of the CeA-vlPAG circuit rescues hyperalgesia in alcohol-dependent adult rats, and photoinhibition of this circuit produces hyperalgesia in naïve rats. Our lab and others find that antagonism of corticotropin-releasing factor type-1 receptors (CRFR1) in CeA reduces hyperalgesia associated with alcohol withdrawal, nicotine withdrawal and traumatic stress in adult rats. Our overarching hypotheses are that chronic intermittent alcohol exposure in adolescent rats (AIE) produces persist long-term effects on polymodal (i.e., mechanical and thermal) hyperalgesia that is mediated by weakened CeA-vlPAG connectivity and increased CRFR1 signaling in CeA. The CRFR1 signaling gating of CeA-vlPAG function is important for mediating AIE-induced hyperalgesia. We include preliminary data showing that 1) AIE produces rapid and long-lasting thermal and mechanical hyperalgesia during adolescence and that this effect persists into adulthood (Fig. 1), 2) AIE reduces synaptic drive and excitatory/inhibitory ratio on vlPAG-projecting medial CeA neurons in adulthood (Fig. 3), 3) CRFR1 is expressed on vlPAG projecting cells (Fig. 2), and 4) validation data for a CRFR1:cre rat for CRFR1+ cell type- specific modulation of CeA outputs (Fig. 4). Because we also propose to challenge rats with a short-lasting inflammatory pain challenge in adulthood, we have also piloted dose-response effects of carrageenan on nociception in adult Wistar rats. Here, we propose aims that will test the hypotheses that AIE produces hyperalgesia during adolescence that persists into adulthood (Specific Aim 1), that AIE reduces synaptic drive and excitatory/inhibitory balance of synaptic transmission onto vlPAG-projecting CeA neurons via a CRFR1- dependent (Specific Aim 2), and that pharmacological, circuit-based, and epigenetic modulation of CRFR1+ PAG- projecting CeA neurons will rescue AIE-induced hyperalgesia and CeA-vlPAG circuit plasticity (Specific Aim 3). Importantly, we propose specific collaborations with Research Component 6 (PI:Chandler) and 5 (PI: Crews) along with the Epigenetics Core (PI: Pandey) of the NADIA consortium. This proposal focuses on testing adolescent alcohol effects on pain-related outcomes and aligns with the overall goal of the NADIA consortium to examine the effects of adolescent alcohol exposure on the adult organism.