Fig. 1

Dbx1-derived interneurons preferentially target OPCs from the same lineage. a Confocal images of YFP⁺ interneurons (green) and YFP⁺/DsRed⁺ OPCs (green and red) in layers V and VI of the somatosensory cortex in a Dbx1^CRE;Rosa26^YFP;NG2^DsRed mouse at PN10. Olig2 (cyan, right) immunolabeling for the same cortical field identifies oligodendroglia within these groups. White dotted squares surround two YFP⁺ cell groups shown in insets. The first group (1) is composed of two YFP⁺ interneurons and the second (2) of a YFP⁺ interneuron and two YFP⁺/DsRed⁺/Olig2⁺ OPCs. Arrowheads point to two other groups of YFP⁺ interneurons. Scale bars: 100 and 10 µm. b Paired recording between a presynaptic YFP⁺ interneuron and a YFP⁺/DsRed⁺ OPC. Action currents evoked in a YFP⁺ interneuron (green) elicited PSCs recorded in a YFP⁺/DsRed⁺ OPC (yellow; average of 100 traces) that were abolished by the GABA_A receptor antagonist SR95531 (5 µM, gray; n = 5 connected pairs). c Connection probabilities for all tested DsRed⁺ OPCs (black, n = 168), YFP⁺/DsRed⁺ OPCs (yellow, n = 56), YFP⁻/DsRed⁺ OPCs (red, n = 118) and postsynaptic YFP⁺ interneurons (green, n = 72). Note that presynaptic YFP⁺ interneurons target preferentially YFP⁺/DsRed⁺ OPCs compared to YFP⁻/DsRed⁺ OPCs or postsynaptic YFP⁺ interneurons (Chi-squared test; significant p-values are indicated). d Connection probabilities for YFP⁺/DsRed⁺ OPCs (yellow) and YFP⁻/DsRed⁺ OPCs (red) as a function of three postnatal stages (PN8-9, PN10-11 and PN12-13; n = 12, n = 17, n = 6 tested pairs for YFP⁺/DsRed⁺ OPCs and n = 15, n = 26, n = 17 tested pairs for YFP⁻/DsRed⁺ OPCs). e Sequential paired recordings between a single presynaptic YFP⁺ interneuron (green) and two different neighbor OPCs, a YFP⁺/DsRed⁺ OPC (yellow) and a YFP⁻/DsRed⁺ OPC (red). Note that action currents evoked in the YFP⁺ interneuron elicited PSCs in the YFP⁺/DsRed⁺ OPC, but not in the YFP⁻/DsRed⁺ OPC. f Connection probabilities for sequential paired recordings revealed a high connection probability for YFP⁺/DsRed⁺ OPCs (yellow) compared to YFP⁻/DsRed⁺ OPCs (red; n = 58 sequential paired recordings) (Chi-squared test)