A computational study of multisensory maturation in the superior colliculus (SC)

Area of Science:

• Neuroscience
• Computational Neuroscience
• Developmental Neuroscience

Background:

• Multisensory neurons in the cat superior colliculus (SC) undergo significant postnatal maturation.
• Initially, these neurons have large receptive fields (RFs) and lack multisensory integration capabilities.
• Maturation involves RF contraction, response enhancement, and the development of multisensory integration, influenced by sensory experience and cortical input.

Purpose of the Study:

• To extend a computational model describing the maturation of multisensory neurons in the SC.
• To elucidate the mechanisms by which sensory experience shapes neuronal receptive fields and integration capacity.

Main Methods:

• A computational model was extended based on biologically realistic assumptions.
• The model simulates early life conditions with inactive cortical-SC synapses and large RFs driven by non-cortical inputs.
• Sensory experience was modeled via a training phase with modality-specific and cross-modal stimuli, modifying synaptic weights using Hebbian learning rules.

Main Results:

• The model demonstrates that repeated sensory exposure leads to RF reduction.
• Synaptic plasticity (potentiation and depression) refines neuronal responses.
• Neurons develop the capacity for adult-like responses to both modality-specific and cross-modal stimuli.

Conclusions:

• The computational model supports the hypothesis that sensory experience drives the maturation of multisensory neurons in the SC.
• Hebbian learning rules are crucial for refining receptive fields and enabling multisensory integration.
• This process results in the development of adult-like neural processing capabilities from initially immature states.