A theoretical model reveals specialized synaptic depressions and temporal frequency tuning in retinal parallel channels

Liuyuan He; Yutao He; Lei Ma; Tiejun Huang

doi:10.3389/fncom.2022.1034446

A theoretical model reveals specialized synaptic depressions and temporal frequency tuning in retinal parallel channels

Front Comput Neurosci. 2022 Nov 16:16:1034446. doi: 10.3389/fncom.2022.1034446. eCollection 2022.

Authors

Liuyuan He¹, Yutao He¹, Lei Ma^{1

2

3}, Tiejun Huang^{1

4

3}

Affiliations

¹ National Engineering Research Center of Visual Technology, School of Computer Science, Peking University, Beijing, China.
² National Biomedical Imaging Center, Peking University, Beijing, China.
³ Beijing Academy of Artificial Intelligence, Beijing, China.
⁴ Institute for Artificial Intelligence, Peking University, Beijing, China.

Abstract

In the Outer Plexiform Layer of a retina, a cone pedicle provides synaptic inputs for multiple cone bipolar cell (CBC) subtypes so that each subtype formats a parallelized processing channel to filter visual features from the environment. Due to the diversity of short-term depressions among cone-CBC contacts, these channels have different temporal frequency tunings. Here, we propose a theoretical model based on the hierarchy Linear-Nonlinear-Synapse framework to link the synaptic depression and the neural activities of the cone-CBC circuit. The model successfully captures various frequency tunings of subtype-specialized channels and infers synaptic depression recovery time constants inside circuits. Furthermore, the model can predict frequency-tuning behaviors based on synaptic activities. With the prediction of region-specialized UV cone parallel channels, we suggest the acute zone in the zebrafish retina supports detecting light-off events at high temporal frequencies.

Keywords: computational modeling; retinal adaptation; retinal circuit; synaptic depression; visual system.