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Online Transcranial Magnetic Stimulation Protocol for Measuring Cortical Physiology Associated with Response Inhibition
Published on: February 8, 2018
Neocortical inhibitory system
1Charles University in Prague, Institute of Anatomy, 2nd and 1st Faculty of Medicine, Prague, Czech Republic. rastislav.druga@lf1.cuni.cz
Folia Biologica
|February 19, 2010
Summary
Neocortical inhibitory interneurons, crucial for brain function, exhibit diverse molecular and physiological properties. Their density decreases in conditions like aging and epilepsy, except for calretinin-expressing cells.
Area of Science:
- Neuroscience
- Cell Biology
- Neuroanatomy
Background:
- The neocortex comprises excitatory pyramidal neurons and diverse inhibitory GABAergic interneurons.
- Inhibitory interneurons constitute 20-25% of neocortical neurons and are key for neural circuit regulation.
- These interneurons display significant molecular, physiological, and axonal targeting heterogeneity.
Purpose of the Study:
- To elucidate the heterogeneity and functional roles of GABAergic interneurons in the neocortex.
- To investigate the origins and migratory patterns of neocortical interneurons.
- To analyze the density changes of specific interneuron populations in neurological conditions.
Main Methods:
- Immunohistochemistry for calcium-binding proteins (parvalbumin, calbindin, calretinin) and other markers.
- Analysis of axonal targeting patterns of different interneuron subtypes.
- Tracing neuronal origins and migration pathways.
- Quantitative density analysis in specific neocortical areas and disease models.
Main Results:
- GABAergic interneurons are classified by axonal targets: basket cells (soma/proximal dendrites), Chandelier cells (axon initial segment), and others (distal dendrites).
- Interneurons originate from ventral telencephalon ganglionic eminences and migrate tangentially.
- Adult neurogenesis in the neocortex produces GABAergic neurons co-expressing calbindin and calretinin.
- A decrease in parvalbumin- and calbindin-expressing interneuron density was observed in aging and epilepsy models, but not calretinin-expressing interneurons.
Conclusions:
- GABAergic interneurons exhibit specialized roles based on their connectivity and molecular profiles.
- The developmental origin and migration of interneurons are critical for cortical circuit formation.
- Specific interneuron populations are vulnerable in aging and epilepsy, highlighting their role in neuropathology.
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