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，从而增加 患上酒精使用障碍(AUD)的风险。急性酒精可减轻疼痛和慢性疼痛(如痛觉过敏) 可通过负性强化止痛作用促进饮酒。矛盾的是，慢性酒精 产生痛觉过敏或恶化先前存在的疼痛状态。最近，我们报道了杏仁中央内侧核 (CEA)向中脑导水管周围灰质(VlPAG)的投射对调节 慢性酒精暴露的成年雄性大鼠的痛敏反应。这种慢性酒精会削弱突触的连接性 在成年雄性大鼠内侧CEA和vlPAG之间，光刺激CEA-vlPAG回路可拯救 酒精依赖成年大鼠的痛觉过敏，而光抑制这一回路在幼稚时会产生痛觉过敏 老鼠。我们的实验室和其他人发现促肾上腺皮质激素释放因子1型受体(CRFR1)在CEA中的拮抗作用 减少与酒精戒断、尼古丁戒断和创伤应激相关的成年大鼠的痛觉过敏。 我们的主要假设是，慢性间歇性酒精暴露在青少年大鼠(AIE)中会产生 对多模式(即，机械和热)痛觉过敏持续的长期影响，这种影响是由减弱的 CEA-vlPAG连接和CRFR1信号在CEA中的增加。CEA-vlPAG的CRFR1信号门控 功能在调节AIE引起的痛敏反应中起重要作用。 我们包括的初步数据表明：1)AIE产生快速和持久的热和机械 青春期的痛觉过敏和这种影响持续到成年(图1)，2)AIE减少突触 成年期vlPAG投射的内侧CEA神经元的驱动和兴奋/抑制比(图3)，3)CRFR1是 在vlPAG投射细胞上表达(图2)，以及4)CRFR1的验证数据：CRFR1细胞类型的CRE RAT- CEA输出的特定调制(图4)。因为我们还提议用一种短期的 在成年期的炎性疼痛挑战中，我们还试验了卡拉胶对 成年Wistar大鼠的伤害性感受。在这里，我们提出的目标将检验AIE产生的假设 持续到成年期的青春期痛觉过敏(特定目标1)，AIE减少突触驱动 以及通过CRFR1向vlPAG投射的CEA神经元的突触传递的兴奋/抑制平衡 依赖(特定目标2)，以及CRFR1的药理、基于电路和表观遗传的调节 投射PAG的CEA神经元将挽救AIE诱导的痛觉过敏和CEA-v1PAG电路可塑性(特异性 目标3)。重要的是，我们建议与Research Component 6(PI：Chandler)和5(PI： Crews)以及Nadia财团的表观遗传学核心(PI：Pandey)。这份提案的重点是测试 青少年酒精对疼痛相关结果的影响，并与Nadia财团的总体目标一致 检查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.