Orientation Maps in Mouse Superior Colliculus Explained by Population Model of Non-Orientation Selective Neurons.

Area of Science:

• Neuroscience
• Computational Neuroscience
• Vision Science

Background:

• Mouse superficial superior colliculus (sSC) exhibits orientation selectivity, contrasting with primate SC.
• Mouse sSC's selectivity varies with stimulus properties, unlike primate visual invariance.

Purpose of the Study:

• Reconcile differing orientation selectivity mechanisms between mouse and primate SC.
• Develop a computational model to explain mouse sSC population activity.

Main Methods:

• Constructed a computational model of mouse sSC using circular-symmetric, center-surround receptive fields (RFs).
• Simulated population activity with stimulus-invariant RFs, classically used for primate lateral geniculate nucleus (LGN) neurons.
• Analyzed the model's dependence on spatial frequency tuning.

Main Results:

• The model successfully reproduced mouse sSC population maps with radial orientation preferences.
• Selectivity was critically dependent on spatial frequency tuning.
• Predicted a shift from radial to anti-radial preferences at high spatial frequencies, matching experimental data.
• Found intrinsically oriented RFs were largely unnecessary for explaining imaging data.

Conclusions:

• Image-computable population modeling provides a solution for studying orientation selectivity, rather than stimulus optimization.
• The framework reconciles cross-species differences in neural selectivity.
• Establishes a unifying approach for inferring neural mechanisms across different scales of measurement.