Transsynaptic delivery of nanoparticles to the central auditory nervous system

Abstract

Fluorescent microscopy demonstrated Cy3-labeled nanoparticles signals in the sensory hair cells and the spiral ganglion neurons of both the treated and contralateral inner ears. Additionally, the distal part of the central auditory pathway (dorsal cochlear nucleus, superior olivary complex) was found to be labeled with the Cy3-linked silica nanoparticles, indicating a retrograde axonal transport. No hearing loss or inflammation was noted in the treated cochlea.

Optogenetic stimulation of the auditory pathway

“…Importantly, biologically safe and reliable protocols for genetic manipulation of SGNs are required. Thus far, viral and nonviral approaches have been reported (53)(54)(55)(56)(57)(58)(59). Here, we focused on using AAVs, which are good candidates, because they were successfully used to transduce murine SGNs (53, 54, 60) and do not compromise hearing (60)(61)(62).…”

Use of a Microendoscope for Transtympanic Drug Delivery to the Round Window Membrane in Chinchillas

“…Another advantage of the transtympanic application on the RWM, through a microendoscope, would be with the application of a slow-release formulation, which will guarantee a sustained contact of the drug to the RWM (5,19) and minimize repetitive application/manipulation of the RWM. Furthermore, it is important to choose a precise and atraumatic delivery method so that the drug application does not affect the normal function of the ear (20). The chinchilla animal model was chosen for this study, as it is an easy to maintain laboratory animal with more anatomic and audiologic ear similarity to that of human beings in comparison to other small rodents (21Y23).…”

Jagged1-mediated Notch signaling regulates mammalian inner ear development independent of lateral inhibition

“…The technique was performed as described previously [9]. Only the left ear from each animal was tested (n = 10 for Jag1-cko, n = 10 for controls Figure 2.…”