Midbrain astrocytes controlling active avoidance learning

学会避免令人厌恶的结果可以促进恢复力，抑制普遍恐惧的表达 在人类身上。因此，人们对识别介导主动回避的细胞过程非常感兴趣 学习主动回避学习的第一步是在厌恶的遭遇中做出积极的反应， 腹侧被盖区（VTA）多巴胺神经元控制的过程。最近的研究表明 学习不仅仅是由神经元驱动，而是由星形胶质细胞-神经元相互作用驱动。因此，必须 确定腹侧被盖区星形胶质细胞如何在令人厌恶的情况下调节多巴胺神经元，以描绘细胞 控制主动回避学习的过程。 星形胶质细胞是局部神经回路的积极参与者，因为它们响应神经递质并释放 发射机本身。特别地，星形胶质细胞上的Gq偶联受体的活化促进星形胶质细胞上的Ca 2 +-Ca 谷氨酸的依赖性释放。进行星形胶质细胞Ca 2+水平的光度计记录，以检查星形胶质细胞的Ca 2+水平。 腹侧被盖区星形胶质细胞的细胞活性。初步研究结果显示VTA星形胶质细胞Ca 2 + 在接受不可避免的电击任务训练的大鼠中，此外，选择性刺激Gq VTA星形胶质细胞中的信号传导减少了在不可避免的应激期间启动动作的潜伏期， 多巴胺水平在脑桥核（NAc）。总之，这些数据突出了VTA星形胶质细胞（1）经历 在厌恶的情况下细胞活动的变化，（2）调节NAc中的多巴胺水平，（3）促进 在不可避免的压力下做出积极的行为反应。积极响应是必要的第一步， 主动回避学习，腹侧被盖区星形胶质细胞可能是控制回避学习的中枢节点。的 这个提议的首要假设是腹侧被盖区星形胶质细胞通过 腹侧被盖区谷氨酸的钙依赖性释放和随后NAc多巴胺水平的升高。到 为了解决这一问题，该提案中的实验将病毒操纵VTA星形胶质细胞Ca 2+信号传导， 记录VTA星形胶质细胞Ca 2+水平、VTA中的神经元谷氨酸信号和NAc中的多巴胺水平。 总的来说，这个建议将描绘腹侧被盖区星形胶质细胞在主动回避学习过程中的作用。

Learning to avoid aversive outcomes promotes resilience and suppresses the expression of generalized fear in humans. As such, there is great interest in identifying the cellular processes that mediate active avoidance learning. The first step in active avoidance learning is to actively respond during the aversive encounter, a process that is controlled by ventral tegmental area (VTA) dopamine neurons. Recent research indicates learning is not solely driven by neurons, but rather by astrocyte-neuron interactions. Therefore, one must determine how VTA astrocytes regulate dopamine neurons during aversive situations to delineate the cellular processes that control active avoidance learning. Astrocytes are active participants in local neural circuits as they respond to neurotransmitters and release transmitters themselves. In particular, activation of Gq coupled receptors on astrocytes promotes the Ca2+- dependent release of glutamate. Photometry recordings of astrocyte Ca2+ levels were performed to examine the cellular activity of VTA astrocytes during aversive situations. Preliminary findings illustrate VTA astrocyte Ca2+ levels increased in rats trained on an inescapable footshock task. Furthermore, selectively stimulating Gq signaling in VTA astrocytes reduced the latency to initiate actions during inescapable stress and elevated dopamine levels in the nucleus accumbens (NAc). Together, these data highlight VTA astrocytes (1) undergo changes in cellular activity during aversive situations, (2) regulate dopamine levels in the NAc and (3) promote active behavioral responses during inescapable stress. Since active responding is a necessary first step for active avoidance learning, VTA astrocytes are likely a central node for controlling avoidance learning. The overarching hypothesis of this proposal is that VTA astrocytes facilitate active avoidance learning through the Ca2+-dependent release of glutamate in the VTA and subsequent elevation of dopamine levels in the NAc. To address this, the experiments in this proposal will virally manipulate VTA astrocyte Ca2+ signaling while recording VTA astrocyte Ca2+ levels, neuronal glutamate signals in the VTA, and dopamine levels in the NAc. Collectively, this proposal will delineate the role of VTA astrocytes during active avoidance learning.