Glia 1 lecture

Introduction to Glial Cells

• Welcome to the series on neuroscience focusing on glia

• Lecturer: Diego Nicola, previously met by some in pharmacology

• Apology for technical issues with slide access

Rules of Engagement

• Open communication encouraged; raise questions during lectures

• Lectures will provide guidance on current understanding, not universal truths

• Students are encouraged to read beyond what is taught

Purpose of Lectures

• Highlight the importance of glial cells in neuroscience

• Aim to shift perception from neurons as the sole functional actors in the brain to include glia

• Will discuss development, functions, and links to brain disorders

Overview of Glial Cells

• Definition and Classification

  • Glia: support cells of the nervous system, outnumber neurons (90% vs. 10%)

  • Types include microglia, astrocytes, oligodendrocytes, and Schwann cells

Development of Glia

• Key Topics

  • Development and lineage of glial cells

  • Interconnection with brain development

  • Specific functions and dysfunction in brain disorders

Key Functions of Glia

• Traditional Functions

  • Provide physical support to neurons

  • Supply nutrients and oxygen

  • Insulate neurons for synaptic communication

  • Remove cellular debris

• Modern Understanding of Functions

  • Participate in neuron migration, synaptic transmission modulation, and involvement in brain diseases

Evolutionary Perspectives

• Glial cell presence increases with organism complexity

• Comparison of glial percentages across species

  • Higher ratios in more complex brains (e.g., humans vs. simpler organisms)

Historical Perspective on Glial Research

• Timeline of Discoveries

  • Rudolf Virchow’s discussions (1856) on glia as supporting structures

  • Otto Dieter's functional characteristics of glia - ectodermic origin

  • Ramón y Cajal’s contributions to classification and origin theories - all glia come from ectoderm

• Shift in focus from glia to neurons in the late 20th century, 4 types by Rio-Hortega

  • Re-emergence of glial research in the 21st century

Understanding Glial Cell Development

• Traditional model shows glial cells arising from ectoderm alongside neurons

• Microglia have a different developmental origin from mesoderm

• Radial glia serve as scaffolding for neuron migration during embryonic development

• Continuous development and specialization of glial cells into adulthood

Summary of Glial Cell Types and Functions

• Major Glial Cell Types

  • Oligodendrocytes and astrocytes in the central nervous system

  • Schwann cells in the peripheral nervous system

  • Ependymal cells in specific contexts

• Functions include mechanical support, metabolic support, and roles in myelination

Glial Cell Developmental Pathways

• Detailed path from neuroepithelial stem cells to specific glial types like astrocytes and oligodendrocytes

• Critical proteins and transcription factors involved in differentiation (e.g., Sox9, Notch1, Prox1)

Heterogeneity Among Glial Cells

• Emerging recognition of diverse subpopulations of astrocytes with unique functions

• Importance of understanding this diversity in health and disease contexts

Conclusion

• Ongoing exploration of glia in neuroscience

• Encouragement for student engagement and questions moving forward in the series

• Prepared to continue in following sessions with specific focus on identified topics.