The Potential Role of Gap Junctional Plasticity in the Regulation of State

• Published in: Neuron (Cambridge, Mass.) Vol. 93; no. 6; pp. 1275 - 1295
• Main Authors: Coulon, Philippe, Landisman, Carole E.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 22.03.2017; Elsevier Limited
• Subjects: Animals; Brain research; Cerebral cortex; Cerebral Cortex - physiology; Consciousness; cortex; electrical synapse; Electrical Synapses - physiology; Electroencephalography; Feedback; firing states; Functional plasticity; Gap junctions; Gap Junctions - physiology; Humans; Mammals; Nervous system; network oscillations; Neural Inhibition - physiology; Neural networks; Neural Pathways - physiology; Neuronal Plasticity - physiology; Neurons; Oscillations; rhythmogenesis; state regulation; Synaptic plasticity; thalamocortical system; Thalamus; Thalamus - physiology; cortex; gap junctions; firing states; thalamocortical system; rhythmogenesis; synaptic plasticity; network oscillations; electrical synapse; thalamus; state regulation
• ISSN: 0896-6273; 1097-4199
• DOI: 10.1016/j.neuron.2017.02.041

Electrical synapses are the functional correlate of gap junctions and allow transmission of small molecules and electrical current between coupled neurons. Instead of static pores, electrical synapses are actually plastic, similar to chemical synapses. In the thalamocortical system, gap junctions couple inhibitory neurons that are similar in their biochemical profile, morphology, and electrophysiological properties. We postulate that electrical synaptic plasticity among inhibitory neurons directly interacts with the switching between different firing patterns in a state-dependent and type-dependent manner. In neuronal networks, electrical synapses may function as a modifiable resonance feedback system that enables stable oscillations. Furthermore, the plasticity of electrical synapses may play an important role in regulation of state, synchrony, and rhythmogenesis in the mammalian thalamocortical system, similar to chemical synaptic plasticity. Based on their plasticity, rich diversity, and specificity, electrical synapses are thus likely to participate in the control of consciousness and attention. Coulon and Landisman’s Review discusses how thalamocortical inhibitory neurons are involved in changes in behavioral states and suggests a role for gap junctional plasticity in regulation of neuronal network rhythmogenesis and states of arousal.