TY - JOUR T1 - Decoupling of timescales reveals sparse convergent CPG network in the adult spinal cord JF - bioRxiv DO - 10.1101/402917 SP - 402917 AU - Marija Radosevic AU - Alex Willumsen AU - Peter C. Petersen AU - Henrik Lindén AU - Mikkel Vestergaard AU - Rune W. Berg Y1 - 2019/01/01 UR - http://biorxiv.org/content/early/2019/02/21/402917.abstract N2 - During generation of rhythmic movements, most spinal neurons receive oscillatory synaptic drive. The neuronal architecture underlying this drive is unknown, and the corresponding network size and sparseness have not yet been addressed. If the input originates from a small central pattern generator (CPG) with dense divergent connectivity, it will induce correlated input to all receiving neurons, while sparse convergent wiring will induce a weak correlation, if any. Here, we use pairwise recordings of spinal neurons to measure synaptic correlations and thus infer the wiring architecture qualitatively. A strong correlation on a slow timescale implies functional relatedness and a common source, which will also cause correlation on fast timescale due shared synaptic connections. However, we consistently found marginal coupling between slow and fast correlations regardless of neuronal identity. This suggests either a sparse convergent connectivity, or a CPG network with recurrent inhibition that actively decorrelates common input. ER -