Cellular Plasticity in the Adult Murine Piriform Cortex: Continuous Maturation of Dormant Precursors Into Excitatory Neurons

This study investigates the fate of immature neurons in the piriform cortex of adult mice. Researchers used transgenic mice to track cells expressing doublecortin (DCX), an immature neuronal marker. The findings indicate that these immature neurons, rather than disappearing with age, gradually mature into glutamatergic neurons. These neurons show signs of functional integration into the surrounding neuronal network. This maturation process outside the typical neurogenic niches suggests a reservoir of cells contributing to cortical plasticity. This could have significant implications for understanding brain aging and potential for plasticity in higher mammals.

• 1
  Immature neurons in the piriform cortex do not vanish with age; instead, they progressively mature into glutamatergic neurons.
• 2
  These maturing neurons develop morphological features indicative of functional integration, including increased synaptic markers, complex apical dendrites with spines, and an axonal initial segment.
• 3
  The study demonstrates a progressive development from small tangled cells to complex cells resembling semilunar–pyramidal transitional neurons over time.