Neural coding in barrel cortex during whisker-guided locomotion

Area of Science:

• Neuroscience
• Sensory Systems
• Computational Neuroscience

Background:

• Sensory systems are typically studied passively, limiting understanding of neural coding in dynamic environments.
• Active sensing, like whisker exploration, is crucial for animals navigating complex worlds.

Purpose of the Study:

• To investigate neural coding in the barrel cortex during active tactile exploration.
• To determine the role of the barrel cortex in wall-tracking behavior using virtual reality.

Main Methods:

• Head-fixed mice explored a tactile virtual reality environment, tracking walls with their whiskers.
• Optogenetic manipulations were used to control neuronal activity in the barrel cortex.
• Two-photon calcium imaging and extracellular recordings captured neural activity.

Main Results:

• The barrel cortex was found to play a role in wall-tracking behavior.
• Optogenetic stimulation of layer 4 neurons could substitute for whisker-object contact to guide wall tracking.
• Neurons in the barrel cortex exhibited tuning to the distance between the snout and the contralateral wall.

Conclusions:

• The barrel cortex represents object location through rich, complex neural tuning curves.
• This representation likely emerges from cortical circuit dynamics rather than simple whisker-stimulus responses.