Generation of Inner Ear Cells

1 . (canceled)

2 . A method of increasing numbers of differentiated inner ear cells in the ear of a subject, the method comprising:

generating a differentiated inner ear cell, using a method comprising:

(i) providing a population of mesenchymal stem cells obtained from mammalian bone marrow;

(ii) culturing the mesenchymal stem cell in serum-free medium containing insulin-like growth factor-1 (IGF-1), epidermal growth factor (EGF), and basic fibroblast growth factor (bFGF);

(iii) inducing the stem cell by maintaining said cell in medium comprising neurotrophin-3 (NT-3) or brain derived neurotrophic factor (BDNF) for time sufficient to differentiate into a progenitor cell that expresses Sox2, Pax6, nestin, and musashih; and

(iv) culturing the progenitor cell in the presence of a gamma secretase inhibitor, wherein the gamma secretase inhibitor is selected from the group consisting of an arylsulfonamide, a dibenzazepine, a benzodiazepine, N—[N-(3,5-difluorophenacetyl)-L-alanyl]-(S)-phenylglycine t-butyl ester (DAPT), L-685,458, and MK0752, in an amount and for a time sufficient to produce a differentiated inner ear auditory hair cell that expresses myosin VIIa, and espin and optionally expresses one or more of atonal homolog 1 (Atoh1), or jagged 2, thereby producing a differentiated inner ear auditory hair cell, and

implanting the differentiated inner ear auditory hair cell into the ear of the subject.

3 . The method of claim 2 , wherein the mesenchymal stem cell is obtained from a subject who has sensorineural hair cell loss.

4 . The method of claim 2 , wherein the differentiated cell is an inner ear auditory hair cell.

5 . The method of claim 4 , wherein the inner ear auditory hair cell expresses Atoh1, myosin7a, and epsin.