What the whiskers tell the brain

Area of Science:

• Neuroscience
• Sensory Systems Biology
• Biophysics

Background:

• The fundamental question of how physical signals activate sensory neurons during natural behavior remains largely unanswered for many systems.
• The rodent whisker system provides a model for investigating sensory-driven neural activity.
• Recent advancements have begun to elucidate the signals processed by primary whisker afferents (PWAs).

Purpose of the Study:

• To review key developments in understanding the physical signals that drive primary whisker afferents (PWAs) during natural behavior.
• To integrate biomechanical principles with electrophysiological and behavioral data.
• To connect PWA function to the computational roles of downstream neural circuits, such as the barrel cortex.

Main Methods:

• Review of existing literature on whisker biomechanics and sensory neuroscience.
• Analysis of technical advancements enabling measurement of mechanical variables in awake, behaving animals.
• Reinterpretation of past electrophysiological data within a biomechanical framework.

Main Results:

• A biomechanical framework has been established to describe forces acting on whiskers during active sensation.
• Technical progress allows for the estimation of these mechanical variables in behaving animals.
• Recent studies provide new insights into PWA function in awake, behaving rodents.

Conclusions:

• Understanding the physical signals conveyed by PWAs is crucial for deciphering sensory processing.
• The biomechanical framework provides a valuable lens for reinterpreting existing and guiding future research on PWAs.
• Insights into PWA function offer significant understanding of the computational roles of downstream neural circuits, including the barrel cortex.