In a study by Morikawa et al., the role of the sodium-bicarbonate cotransporter Slc4a5 in retinal feedback mechanisms is investigated. Located in horizontal cells, Slc4a5 regulates pH in the synaptic cleft, affecting calcium channel activity and cone sensitivity to light. The researchers used knockout mice and calcium imaging to show that the absence of Slc4a5 eliminates feedback from horizontal cells to cones while maintaining synaptic structure. This research enhances the understanding of visual processing and offers insights for potential treatments for vision disorders related to synaptic dysfunction.

We supported the work with our 3dEMtrace platform, helping map interactions between cones and horizontal cells at the level of synaptic ultrastructure.

The original publication:
The sodium-bicarbonate cotransporter Slc4a5 mediates feedback at the first synapse of vision