German researchers investigating four extracellular matrix proteins, brevican, neurocan, tenascin-C and tenascin-R, reported their cumulative loss reinforced optomotor limitations in mice.  

Studying the proteins’ visual function in knockout mice, a Ruhr-University Bochum team found rod photoreceptors and bipolar cells exhibited functional deficits in visual processing. “Interestingly, we were also able to find significant limitations in visual movement processing in the knockout mice compared to control animals,” said co-author Dr Jacqueline Reinhard-Recht. Mice lacking only the proteins tenascin-C or tenascin-R also displayed losses in visual motion processing, but much weaker, she said.  

The team also observed changes in various matrix molecules and synapses in the mice’s retinas. “In particular, there was an imbalance of inhibitory and excitatory synapses,” said Dr Reinhard-Recht. In future, these findings could offer new approaches for the development of therapeutic interventions for visual function disorders, she said. 

The study was published in Cell.