Members of the nAChR family contribute to essentially all aspects of the auditory sensory system function and development (Morley and Happe 2000; Morley 2005) . This includes widespread changes in expression during embryogenesis that optimizes their contribution to signal transduction, fine-tuning of sensory hair cells, and modulating central auditory circuit neurotransmission (Elgoyhen et al. 1994 (Elgoyhen et al. , 2001a Happe and Morley 1998; Vetter et al. 1999 Vetter et al. , 2007 Morley and Happe 2000; Katz et al. 2004; Morley 2005) . This functional diversity is in part accomplished through strict spatiotemporal control of different nAChR subunit expression, as has been extensively described for the nAChRs composed of either homomeric (a9) or heteromeric (a9 + a10) subunits (Elgoyhen et al. 1994; Vetter et al. 1999 Vetter et al. , 2007 Elgoyhen et al., 2001b; Murthy et al. 2009) . Less is known about the role of other nAChRs including a7, although this receptor is implicated in modifying longer lived stimulation by high-frequency sound and supporting survival of spiral ganglion cells during development (Morley and Happe 2000; Morley 2005) . Because the measurement of a7 expression and function can be compromised by low receptor expression levels or the absence of conditions that best reveal its modulatory role (Gahring and Rogers 2005; Albuquerque et al. 2009 ), the participation by this receptor as an important contributor to the development and normal auditory sensory function remains to be fully explored.