Experience-dependent changes in function and anatomy of adult barrel cortex

Area of Science:

• Neuroscience
• Sensory processing
• Cortical plasticity

Background:

• The barrel cortex processes sensory information from whiskers.
• Sensory input can alter the functioning of the barrel cortex in adult animals.

Purpose of the Study:

• To investigate how changes in sensory input to vibrissal mechanoreceptors affect the barrel cortex's functional organization and circuitry in adult mice.

Main Methods:

• Partial vibrissectomy in young adult mice.
• 2-deoxyglucose autoradiography to visualize cortical activity.
• Investigation of cortico-cortical connections in living slices.
• Analysis of dendritic spine density.

Main Results:

• Partial whisker removal led to an enlarged functional cortical area for spared whiskers, particularly in layer V.
• This enlargement persisted and accentuated over two months.
• Whisker deprivation decreased the cortical representation area.
• Spared whisker columns showed axonal elongation and increased branching.
• Dendritic spine density changed in specific neuronal layers.

Conclusions:

• Prolonged changes in functional activation of the adult barrel cortex are associated with significant rearrangements in cortico-cortical circuitry.
• These findings demonstrate experience-dependent plasticity in the adult somatosensory cortex.