Acoustic and electrical hearing after Atoh1 treatment

我们最近证明，新的内毛细胞（IHC）产生的哺乳动物 Corti器官的基因治疗。具体地，实验涉及在体内接种一种 将Atohl基因插入的腺病毒载体（M.Atohl）插入成熟的预消化豚鼠耳蜗中。 我们还证明了新的毛细胞可以吸引神经元。预处理耳， Atohl表现出部分恢复功能，如Preyer反射和声诱发的 听性脑干反应（ABR）阈值。在本申请中，我们提出使用动物- 心理物理学技术和生理措施，以确定恢复的性质和程度， 听觉我们还将进行与使用Atohl疗法相关的实验， 与耳蜗植入物结合。 对于前两个具体目标，我们将用耳毒性药物对豚鼠进行麻醉， 并测量心理物理检测（目标1）和辨别力（目标2）以及ABR和失真 产品耳声发射（DPOAEs）。在目标3中，我们将评估M.Atohl 接种、耳蜗植入和耳蜗植入的电刺激。在目标4中， 将人工耳蜗植入到接种的耳朵中， 刺激和电诱发复合动作电位（ECAP），有和没有恢复的IHC。 具有一些存活毛细胞的对照（即，植入但未预植入的动物）将被使用 与毛细胞恢复的动物进行比较。 我们提出的实验涉及使用我们已经到位的技术， laboratories.这项工作得到了强有力的初步数据的支持，代表了以下方面的理想结合： 风险相对较低，但影响很大。建议的实验将加强我们对 哺乳动物耳蜗毛细胞再生的功能意义，并有助于 人工耳蜗联合应用治疗感音神经性聋的临床研究 细胞替代疗法移植。

We have recently demonstrated that new inner hair cells (IHCs) are generated in the mammalian organ of Corti following gene therapy. Specifically, the experiments involve in vivo inoculation of an adenovirus vector with the Atohl gene insert (M.Atohl) into the mature predeafened guinea pig cochlea. We have also demonstrated that the new hair cells can attract neurons. Predeafened ears treated with Atohl exhibit partial restoration of function as determined by Preyer's reflex and acoustically-evoked auditory brainstem response (ABR) thresholds. In the current application we propose to use animal- psychophysics techniques and physiological measures to define the nature and extent of the restored acoustic hearing. We will also conduct experiments relevant to the use of this Atohl therapy in conjunction with cochlear implants. For the first two specific aims we will deafen guinea pigs with ototoxic drugs, treat them with Atohl and measure psychophysical detection (Aim 1) and discrimination (Aim 2) as well as ABRs and distortion product otoacoustic emissions (DPOAEs). In Aim 3, we will assess the interaction between M.Atohl inoculation, cochlear implantation, and electrical stimulation of the cochlear implant. In Aim 4 we will place a cochlear implant in the inoculated ear and assess psychophysical responses to electrical stimulation and electrically evoked compound action potentials (ECAPs) with and without restored IHCs. Controls with some surviving hair cells (i.e., animals that are implanted but not predeafened) will be used for comparison to animals with restored hair cells. The experiments we propose involve the use of techniques that are already in place in our laboratories. The work is backed by strong preliminary data, and represents an ideal combination of relatively low-risk with very high impact. The proposed experiments will enhance our understanding of the functional significance of hair cell regeneration in the mammalian cochlea and contribute to the development of a clinical therapy for sensorineural deafness involving the combined use of cochlear implantation with cell replacement therapy.