Inhibition of TrkB- and TrkC-Signaling Pathways Affects Neurogenesis in the Opossum Developing Neocortex

Area of Science:

• Neuroscience
• Developmental Biology
• Cell Biology

Background:

• TrkB and TrkC signaling pathways influence neurogenesis in vitro.
• Neocortical development involves complex processes of progenitor cell proliferation, differentiation, survival, and migration.

Purpose of the Study:

• To investigate the in vivo role of TrkB and TrkC signaling in neocortical progenitor cell populations during development.
• To determine if TrkB and TrkC signaling affect progenitor cell proliferation, differentiation, survival, and neuron migration in the Monodelphis opossum.

Main Methods:

• Inhibition of TrkB and TrkC signaling pathways in vivo within the developing neocortex of Monodelphis opossum.
• Analysis of progenitor cell proliferation, differentiation, apoptosis, and neuron migration to the subplate zone.

Main Results:

• Inhibition of TrkB and TrkC signaling affected progenitor cell proliferation, with TrkC showing a more significant impact on cell division rates.
• Unlike in vitro findings, TrkB and TrkC inhibition did not alter apoptosis in vivo.
• Disruption of TrkB and TrkC signaling led to the arrest of newly generated neurons, preventing their penetration of the subplate zone.

Conclusions:

• TrkB and TrkC signaling are essential for regulating progenitor cell proliferation and the rate of cell division during neocortex formation.
• Neuron migration appears to be a two-step process, with TrkB and TrkC signaling specifically regulating the second step of migration to the final position within the subplate.
• The in vivo functions of TrkB and TrkC in neocortical development differ from their roles observed in primary cell cultures, particularly concerning apoptosis.