Calcium Imaging In Electrically Stimulated Flat-Mounted Retinas

Although there have been attempts to test retinal implantable devices using ex vivo methods, a thorough and detailed protocol from sample obtention to data analysis has been lacking. With this work, we aim to fill this gap providing researchers from different backgrounds with the necessary tools to confidently embark on neural retinal stimulation experiments. Calcium imaging is a popular technique for studying neural activity that offers several advantages over non-optical methods.

It provides cellular resolution and can target the specific cell types. It is particularly useful for testing new MEAs as it allows discrimination between active and inactive cells upon electrical stimulation. We are introducing a robust methodology for studying the responses of the retinal neurons by the use of calcium imaging.

This approach could offer insight into selective excitation of the cells, a critical step in developing better stimulation protocols, improving implant performance, and advancing the state of the art. Our laboratory focus on developing advanced microscopy techniques. Currently, we are working in recording calcium dynamics in 3D to gain a better understanding of the negative interaction in the whole tissue.