Acoustic and electrical hearing after Atoh1 treatment

描述（由申请人提供）：我们最近证明，在基因治疗后，在哺乳动物Corti器官中产生了新的内毛细胞（IHC）。具体地，实验涉及将具有Atoh1基因插入物的腺病毒载体（Ad.Atoh1）体内接种到成熟的预处理的豚鼠耳蜗中。我们还证明了新的毛细胞可以吸引神经元。用Atoh1处理的预处理耳表现出部分恢复功能，如通过Preyer反射和声诱发听觉脑干反应（ABR）阈值所确定的。在本申请中，我们提出使用动物心理物理学技术和生理测量来定义恢复的听觉的性质和程度。我们还将进行与Atoh1疗法结合人工耳蜗植入使用相关的实验。对于前两个具体目标，我们将用耳毒性药物麻醉豚鼠，用Atohl 1治疗它们，并测量心理物理检测（目标1）和辨别力（目标2）以及ABR和畸变产物耳声发射（DPOAE）。在目标3中，我们将评估Ad.Atoh1接种、人工耳蜗植入和人工耳蜗电刺激之间的相互作用。在目标4中，我们将在接种的耳朵中放置人工耳蜗植入物，并评估对电刺激和电诱发复合动作电位（ECAP）的心理物理反应，有和没有恢复的IHC。具有一些存活毛细胞的对照（即，植入但未预处理的动物）将用于与具有恢复的毛细胞的动物进行比较。我们提出的实验涉及使用我们实验室中已经存在的技术。这项工作得到了强有力的初步数据的支持，代表了相对低风险和非常高影响的理想组合。拟议的实验将提高我们的理解的哺乳动物耳蜗毛细胞再生的功能意义，并有助于发展的临床治疗感音神经性耳聋，涉及联合使用人工耳蜗植入与细胞替代疗法。

DESCRIPTION (provided by applicant): 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 Atoh1 gene insert (Ad.Atoh1) into the mature predeafened guinea pig cochlea. We have also demonstrated that the new hair cells can attract neurons. Predeafened ears treated with Atoh1 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 Atoh1 therapy in conjunction with cochlear implants. For the first two specific aims we will deafen guinea pigs with ototoxic drugs, treat them with Atohl1 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 Ad.Atoh1 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.