PT  - JOURNAL ARTICLE
AU  - Christian Behrens
AU  - Timm Schubert
AU  - Silke Haverkamp
AU  - Thomas Euler
AU  - Philipp Berens
TI  - Connectivity map of bipolar cells and photoreceptors in the mouse retina
AID  - 10.1101/065722
DP  - 2016 Jan 01
TA  - bioRxiv
PG  - 065722
4099  - http://biorxiv.org/content/early/2016/07/26/065722.short
4100  - http://biorxiv.org/content/early/2016/07/26/065722.full
AB  - Visual processing begins at the first synapse of the visual system. In the mouse retina, three different types of photoreceptors provide input to 14 bipolar cell (BC) types. Classically, most BC types are thought to contact all cones within their dendritic field; ON BCs would contact cones exclusively via so-called invaginating synapses, while OFF BCs would form basal synapses. By mining publically available electron microscopy data, we discovered interesting violations of these rules of outer retinal connectivity: ON BC type X contacted only ~20% of the cones in its dendritic field and made mostly atypical non-invaginating contacts. Types 5T, 5O and 8 also contacted fewer cones than expected. In addition, we found that rod BCs received input from cones, providing anatomical evidence that rod and cone pathways are interconnected in both directions. This suggests that the organization of the outer plexiform layer is more complex than classically thought.