Postnatal Changes of Neural Stem Cells in the Mammalian Auditory Cortex

Area of Science:

• Neuroscience
• Developmental Biology
• Auditory System Research

Background:

• Previous research identified neural stem cells (NSCs) in the auditory cortex (AC) of postnatal day 3 (P3) mice in vitro.
• The in vivo existence and developmental changes of AC-NSCs remained undetermined.

Purpose of the Study:

• To investigate the presence and developmental trajectory of AC-NSCs in vivo and in vitro.
• To analyze the changes in AC-NSC numbers and proliferation during postnatal development and maturation.

Main Methods:

• Immunostaining for NSC markers (Nestin, Sox2) in fixed and cryosectioned mouse brain tissues (P3, P14, 2M, 4M).
• In vitro culture of dissected AC tissues from P3, P14, and 2M mice to assess neurosphere formation and proliferation.
• EdU incorporation and cell doubling time assays to evaluate NSC proliferation in vitro.

Main Results:

• Nestin and Sox2 double-positive NSCs were detected in the mouse AC from P3 to 4M in vivo, with a notable age-related reduction in number.
• In vitro studies showed a significant decline in neurosphere-forming capacity, proliferation rates, and the percentage of double-positive NSCs with increasing age.
• Both in vivo and in vitro data indicate a decrease in AC-NSC populations during postnatal development and maturation.

Conclusions:

• Auditory cortex neural stem cells (AC-NSCs) are present in mice, both in vitro and in vivo.
• The population and proliferative potential of AC-NSCs diminish progressively during postnatal development and maturation.
• Findings offer crucial insights for future research on the central auditory system's development and plasticity.