Gap Junctions in the Brain: Hardwired but Functionally Versatile

Area of Science:

• Neuroscience
• Cellular Neuroscience
• Computational Neuroscience

Background:

• Gap junctions in the brain primarily connect neuronal compartments like dendrites, somata, and axons.
• These electrical synapses provide bidirectional metabolic and electrical coupling.
• While plasticity of electrical synapses is known, the existence of silent, activatable gap junctions is a recent discovery.

Purpose of the Study:

• To explore the implications of silent, activatable gap junctions in neuronal circuits.
• To investigate how changes in the synaptic microenvironment can modulate electrical coupling.
• To examine the potential for gap junctions to reconfigure neuronal ensembles and network properties.

Main Methods:

• Review of recent evidence on gap junction plasticity and function.
• Theoretical exploration of the interaction between chemical and electrical synapses.
• Re-evaluation of historical concepts of neural continuity and contiguity in light of new findings.

Main Results:

• Silent, activatable gap junctions can be integrated into neural circuits, altering connectivity.
• The synaptic microenvironment can dynamically control the presence or absence of electrical coupling.
• Co-localization of gap junctions with glutamatergic synapses suggests combined electrical and metabolic coupling.

Conclusions:

• Dynamic modulation of gap junctions offers a mechanism for neural ensemble reconfiguration.
• The interplay between chemical and electrical synapses may lead to emergent network properties.
• Investigating gap junction versatility can enhance understanding of neural and network postulates.