Robust microcircuit synchronization by inhibitory connections
Attila Szücs1, Ramon Huerta, Mikhail I Rabinovich
1Institute for Nonlinear Science, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0402, USA. aszucs@ucsd.edu
Neuron
|February 17, 2009
Summary
Central pattern generators (CPGs) are models for brain microcircuit synchronization. Lobster pyloric CPGs coupled via artificial synapses demonstrate that inhibitory connections yield robust synchronization, with contralateral inhibition offering flexible phase control.
Area of Science:
- Neuroscience
- Computational Neuroscience
- Systems Neuroscience
Background:
- Microcircuits in various brain regions exhibit properties similar to central pattern generators (CPGs).
- CPGs are valuable models for studying microcircuit dynamics, particularly synchronization.
- The lobster pyloric CPG is a well-characterized compact motor network.
Purpose of the Study:
- To investigate intercircuit synchronization principles using the lobster pyloric CPG.
- To explore how synapse topology and kinetics influence synchronization between coupled CPGs.
- To validate findings using a conductance-based mathematical model.
Main Methods:
- Coupling two separate lobster pyloric CPGs using artificial synapses.
- Systematically varying the topology and kinetic parameters of the artificial synapses.
- Analyzing synchronization patterns, including phase relationships and regularity.
- Developing and utilizing a conductance-based mathematical model of the coupled circuits.
Main Results:
- Electrical coupling of pacemaker groups resulted in stable in-phase synchronization.
- Reciprocal inhibitory connections led to more robust and regular cooperative activity.
- Contralateral inhibitory connections achieved effective synchronization and flexible control of burst phases.
- The mathematical model accurately reproduced the observed synchronization dynamics.
Conclusions:
- The lobster pyloric CPG serves as a robust model for studying intercircuit synchronization.
- Synaptic topology and kinetics significantly impact synchronization patterns.
- Inhibitory connections, particularly contralateral ones, offer effective and flexible synchronization strategies.
- The findings highlight the generality of synchronization phenomena across coupled neural networks.
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