Auckland hearing science discovery and translation in purinergic signaling and inner ear therapeutics

The inner ear is a complex sensory organ responsible for hearing and balance. It is deeply embedded in the temporal bone with challenging access for diagnostic and therapeutic purposes. Stress and injury to the peripheral hearing organ (cochlea) lead to temporary or permanent sensorineural hearing loss (SNHL), which is the most common form of hearing loss resulting from cellular and molecular damage to the sensory hair cells and primary auditory neurons in the spiral ganglion. These cells cannot regenerate, and their loss leads to hearing disability. Hearing aids can amplify sound and improve residual hearing ability but cannot restore function; therefore, alternative therapies are urgently needed. The pharmacological approach to treating SNHL has been our mainstream research over the past two decades. This review describes our studies investigating the purinergic signalling system in the cochlea and its implications for inner ear therapies. Using animal models of SNHL, we have established that purinergic P1 (adenosine) and P2 (ATP) receptors can prevent or mitigate cochlear injury by reducing cochlear sensitivity to loud sound and improving the survival of sensorineural tissues. Here, we highlight our research investigating the therapeutic potential of P1 and P2 receptor agonists and antagonists in inner ear disorders.