Simple fall-off pattern of correlated neural activity in the developing lateral geniculate nucleus

Area of Science:

• Neuroscience
• Computational Neuroscience
• Developmental Neuroscience

Background:

• Activity-dependent models predict specific correlated neural activity patterns in the visual pathway.
• These predicted patterns, like the Mexican hat shape in the lateral geniculate nucleus (LGN), have not been experimentally verified.

Purpose of the Study:

• To experimentally investigate the patterns of correlated neural activity in the developing LGN.
• To reconcile experimental findings with Hebbian models of cortical simple-cell receptive field development.

Main Methods:

• Performed multielectrode recordings in the LGN of immature awake ferrets.
• Utilized computer simulations to model cortical receptive field development.

Main Results:

• Observed simple fall-off-shaped, not Mexican hat-shaped, patterns of correlated activity in the LGN.
• Identified a weak receptive field surround and input statistics as contributors to the observed activity patterns.
• Demonstrated that simple-cell receptive fields emerge with a 'split' synaptic growth constraint and Hebbian modification rules.

Conclusions:

• Experimental patterns of LGN correlated activity are compatible with Hebbian models of cortical development.
• Specific developmental constraints on synaptic plasticity are crucial for receptive field formation.