Partial Cone Loss Triggers Synapse-Specific Remodeling and Spatial Receptive Field Rearrangements in a Mature Retinal...

Area of Science:

• Neuroscience
• Vision Science
• Retinal Circuitry

Background:

• Neural circuit resilience is key for maintaining function despite neuronal loss.
• Vision can be preserved after significant cone photoreceptor loss.
• Cell-type-specific circuit contributions to resilience remain largely unknown.

Purpose of the Study:

• To investigate the impact of partial cone loss on mature mouse retinal circuits.
• To understand how specific cell types and their connections contribute to functional resilience.

Main Methods:

• Studied partial cone loss in mature mouse retinas with known cell types and connections.
• Analyzed remodeling at first-order (bipolar cell) and second-order (ganglion cell) synapses.
• Assessed functional changes in ganglion cell spatio-temporal receptive fields.

Main Results:

• Bipolar cell dendrites remodeled, and synaptic proteins decreased at sites of input loss.
• Second-order synapses remained stable, preserving ganglion cell receptive field structure.
• Functional adaptations included slower temporal filters and expanded receptive field surrounds, mediated by inhibitory inputs.

Conclusions:

• Retinal circuits exhibit functional resilience to cone input loss.
• Remodeling of bipolar cells and stable second-order synapses contribute to this resilience.
• Observed adaptations exceed mechanisms found in control retinas, indicating novel resilience pathways.