Developing a noninvasive method to manipulate specific cell types within the mammalian brain

总结 神经科学的一个核心挑战是开发操纵细胞内特定细胞类型的方法 哺乳动物的大脑光遗传学的最新发展已经彻底改变了我们控制细胞活性的能力。 神经元和非神经元细胞。然而，这种方法有一个缺点，即难以实现。 将光刺激传递到位于大脑或身体深处的目标细胞。查拉萨尼实验室 最近展示了一种非侵入性的方法来控制神经元的活动。他们发现了一个孔- 形成对低强度超声有反应的机械敏感通道（TRP-4）的亚基。他们进一步 表明表达这种通道是特异性细胞，使这些靶细胞对机械敏感， 由非侵入性超声波产生的变形。该提案旨在发展这种方法（它们 被称为“声遗传学”）来控制小鼠脑内的特定细胞。此外，他们发现， 方法可用于控制体外哺乳动物神经元的活性。他们计划用一个高- 用于测试TRP-N家族的其他成员是否对超声敏感的通量测定系统 脉搏此外，他们还将分析改变锚蛋白重复序列的数量是否会影响细胞的增殖。 这些通道的超声响应性（与最近的一项研究一致，该研究显示了在这些通道中的类似结果）。 果蝇TRP-N通道）（目的1）。他们还计划开发一种新的头部设备， 图2示出了用于将超声波刺激递送到小鼠大脑的轻型超声波换能器（Aim 2）。最后，他们会 使用电生理学和行为分析测试声遗传方法在体内的功效。他们 将在皮质PV中间神经元、纹状体D1或D2培养基中表达TRP-4或其他机械敏感通道 刺状投射神经元并控制它们在体内的活动。光遗传学方法先前已用于 控制这些细胞群体，提供用于比较的基准。这些研究将开发一种非侵入性的 操纵啮齿动物大脑或其身体内特定细胞活动的方法。此外，这些方法 可以被翻译到人体中以靶向特定的细胞群体用于治疗目的。

Summary A central challenge in neuroscience is to develop methods to manipulate specific cell types within the mammalian brain. Recent developments in optogenetics have revolutionized our ability to control the activity of both neurons and non-neuronal cells. However, this approach suffers from one drawback, the difficulty in delivery light stimulus to target cells that are located deep within the brain or the body. The Chalasani lab has recently demonstrated a noninvasive method to control the activity of neurons. They have identified a pore- forming subunit of a mechanosensitive channel (TRP-4) that responds to low-intensity ultrasound. Further, they showed that expressing this channel is specific cells renders those target cells sensitive to mechanical deformations generated by noninvasive ultrasound waves. This proposal aims to develop this approach (they have termed “sonogenetics”) to control specific cells within the mouse brain. Further, they find that this approach can be used to control the activity of mammalian neurons in vitro. They plan on using a high- throughput assay system to test whether other members of the TRP-N family are sensitive to ultrasound pulses. Additionally, they will also analyze whether altering the number of ankyrin repeats affects the ultrasound responsiveness of these channels (consistent with a recent study showing similar results in the Drosophila TRP-N channel) (Aim 1). They also plan on developing a new head device with a slot for a tiny, lightweight ultrasound transducer to deliver ultrasound stimulus to the mouse brain (Aim 2). Finally, they will test the efficacy of the sonogenetic approach in vivo using electrophysiological and behavioral analysis. They will express TRP-4 or other mechanosensitive channels in cortical PV interneurons, striatal D1 or D2 medium spiny projection neurons and control their activity in vivo. Optogenetic methods have been previously used to control these cell populations providing benchmarks for comparison. These studies will develop a noninvasive method to manipulate the activity of specific cells within the rodent brain or its body. Further, these methods can be translated into the human to target specific cell populations for therapeutic purposes.