Adult neuroplasticity employs developmental mechanisms

Area of Science:

• Neuroscience
• Developmental Neuroscience

Background:

• The concept of adult neural plasticity was historically challenged by the idea of a critical developmental period after which the brain's ability to change diminishes.
• Early research on adult plasticity, particularly in visual systems and somatosensory pathways, provided initial evidence against this immutable view of the mature brain.

Approach:

• Investigated functional reorganization in adult animal models, including rats and primates, following somatosensory thalamus lesions and peripheral nerve injuries.
• Examined the physiological, morphological, and neurochemical mechanisms underlying adult neural plasticity.
• Tracked the expression of glutamate (AMPA, NMDA) and GABA (GABAA, GABAB) receptor subunits in primate somatosensory cortex after peripheral nerve injury.

Key Points:

• Peripheral nerve injuries in adult primates induced significant reorganization in the somatosensory cortex, occurring in immediate and protracted stages.
• Receptor subunit mapping revealed that adult brain plasticity, under prolonged sensory deprivation, mirrors the molecular states observed during early critical developmental periods.
• This suggests a recapitulation of developmental plasticity mechanisms in the adult brain.

Conclusions:

• Adult neural plasticity is a significant phenomenon, not limited by developmental critical periods.
• The adult brain can revert to a developmental-like plastic state through mechanisms involving glutamate and GABA receptor regulation.
• Understanding these mechanisms offers insights into brain repair and therapeutic interventions.