A Characterization of the Connexin-36 Gap Junction Synapses of Type 3A Bipolar Cells in the Mouse Retina

Vision accounts for approximately 80% of human sensory perception. Visual information processing starts in the retina of the eye, where images are detected and encoded. Retinal cells send and receive signals through chemical synapses (using neurotransmitters) or electrical synapses (using the direct passage of ions through gap junctions). Certain retinal cell types are known to communicate using both chemical and electrical synapses, depending on the postsynaptic target. One such cell type is the type 3A bipolar cell (3A-BC) that, besides utilizing glutamatergic chemical synapses to convey information onto inner retinal ganglion cells (RGCs) and amacrine cells (ACs), expresses connexin-36 (Cx36) gap junction proteins as well (unpublished data, retinal research group, Szentágothai Research Centre, Hungary). This finding is somewhat surprising as bipolar cell gap junctions have rarely been found previously in the mammalian retina (Mills, 1999; Kántor et al., 2016, 2017). The purpose of this project is to characterize these 3A-BC gap junctions in the mouse retina, focusing specifically on the following properties: gap junction distribution on the 3A-BC axon terminals, postsynaptic partners of 3A-BCs, the relative localization of 3A-BC electrical and chemical synapses and the expression of Cx36 and Cx45 gap junction protein plaques in these 3A-BC gap junctions.

Faculty Supervisor:

Sarah McFarlane

Student:

Partner:

University of Pécs

Discipline:

Life Sciences

Sector:

Life Sciences (not health)

University:

University of Calgary

Program: