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

摘要 神经科学中的一个中心挑战是开发方法来操纵特定类型的细胞 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大脑中 无论是神经元还是非神经元细胞。然而，这种方法有一个缺点，即很难 将光刺激传递给位于大脑或身体深处的靶细胞。Chalasani实验室已经 最近展示了一种非侵入性的方法来控制神经元的活动。他们发现了一个毛孔- 形成对低强度超声波有反应的机械敏感通道(Trp-4)的亚基。此外，他们还 表明表达该通道是特定的细胞使这些靶细胞对机械性 由非侵入性超声波产生的变形。本提案旨在发展这一方法(他们 被称为“声遗传学”)来控制小鼠大脑中的特定细胞。此外，他们发现这一点 该方法可用于控制哺乳动物神经元的体外活性。他们计划用一种高能- 用于测试Trp-N家族的其他成员是否对超声波敏感的吞吐能力测定系统 脉搏。此外，他们还将分析改变锚定蛋白重复的数量是否会影响 这些通道的超声响应性(与最近的一项研究一致，该研究在 果蝇Trp-N通道)(目标1)。他们还计划开发一种新的头部设备，上面有一个插槽，可以容纳一个微小的， 轻型超声换能器将超声刺激传递到小鼠的大脑(目标2)。最后，他们会 通过电生理和行为学分析，在体内测试声学方法的有效性。他们 将在皮质PV中间神经元、纹状体D1或D2介质中表达Trp-4或其他机械敏感通道 刺状投射神经元并在体内控制它们的活动。光遗传方法以前已经被用来 控制这些细胞数量，为比较提供基准。这些研究将开发一种非侵入性的 控制啮齿动物大脑或身体内特定细胞活动的方法。此外，这些方法 可以翻译成人类，以靶向特定的细胞群用于治疗目的。

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.