Half-Center Oscillator model database (HCO-db)

The target of this project is to understand how intrinsic membrane and synaptic parameters affect the electrical activity of a half-center oscillator model (HCO) and how different parameter regimes influence stability and modulatability of the HCO model’s output.


A half-center oscillator (HCO) is a common circuit building block of central pattern generator (CPG) networks that produce rhytmic motor patterns in animals. Hill et al.'s HCO simple conductance-based model replicates the electrical activity of the oscillator interneurons of the leech heartbeat CPG under a variety of experimental conditions. This model consists of two reciprocally inhibitory interneurons that make reciprocal spike-mediated and graded synapses across the ganglionic midline.


We systematically explored the parameter space of about 10.4 million simulated HCO instances and corresponding isolated neuron model simulations obtained by varying a set of selected parameters (maximal conductance of intrinsic and synaptic currents) in all combinations using a brute-force approach. We classified these HCO instances by their activity characteristics into identifiable groups. We built an efficient relational database (HCO-db) with the resulting instances characteristics. By efficiently querying the database we can answer to our questions regarding the biological implications of these HCO models.



HCO model files (implemented in Genesis 2.3)

Description of parameter space and simulation files

Group classification algorithm

The HCO-db database (in MySQL)



1. Doloc-Mihu A, Calabrese RL (2011). A database of computational models of a half-center oscillator for analyzing how neuronal parameters influence network activity. J Biol Phys, Springer, 37(3): 263-283 [PubMed].

2. Hill AA, Lu J, Masino MA, Olsen OH, Calabrese RL (2001) A model of a segmental oscillator in the leech heartbeat neuronal network. J Comput Neurosci 10:281-302 [PubMed]


Last updated June 22, 2012. Please send comments to