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. Author manuscript; available in PMC: 2014 Aug 5.
Published in final edited form as: Neuron. 2014 Feb 5;81(3):574–587. doi: 10.1016/j.neuron.2013.11.024

Figure 1. Increase in interneuron numbers in the cerebral cortex of adult Olig1-null mutant mice.

Figure 1

(a) Representation of regions of secondary somatosensory cortex (S2) and primary motor cortex (M1) in which INs were quantified. (b) Representative images of parvalbumin (PV) in wild type (WT) versus Olig1-null (Olig1−/−) motor cortex. Note the increased number of PV+ cell bodies. (c) Representative image showing increases in PV+ (red) synaptic puncta localized to NeuN+ (blue) soma in Olig1−/− vs. WT M1. Arrowheads point to soma localized PV+ puncta, asterisks denote non soma localized puncta. (d) Quantification of PV+ synaptic puncta colocalizing NeuN positive soma in M1 (e) Representative image showing VGAT (green), PV (red), and NeuN (blue). As shown in the boxed region VGAT+ (green) / PV- (red) synaptic puncta in dendritic fields (DF) are identical in Olig1−/− vs. WT M1. Note that PV+ (red) puncta colocalize VGAT confirming they label GABAergic synapses (f) Quantification of the number of VGAT+ puncta in dendritic fields demonstrating that there is not a significant increase in the number of VGAT+ neuronal synapses in dendritic fields of Olig1−/− cortex vs. WT. (g –k) Representative images of INs in Olig1−/− and Wild Type cortex. Arrows point to cell bodies of cell types for which significant differences were observed. (g–h) 2 µm confocal projections of pan IN markers GAD67 (g) and GABA (h). (i–k) 2 µm confocal projections of IN subtype markers Somatostatin (SST) (i), Calretinin (CR) (j), and Neuropeptide Y (NPY) (k). (l–m) Quantification of the number of cells expressing the pan IN markers (l) and IN subtypes (m). Cell counts were taken from micrographs of S2 and M1 in 2 anterior to posterior serial coronal sections as shown in (a). (n–q) Quantification of the number of cells expressing IN subtypes within distinct lamina of the cortex (II/III, IV, V/VI) as demonstrated in panel (b). Cell counts were taken from micrographs of S2 and primary M1 (For all quantifications: mean +/− SEM, n = 3–4; *p<.05, **p<.01, ***p<.005; 2 tailed unpaired student’s t test). (b’,e’,k”) Scale bar = 50 µm, (c’) scale bar = 5 µm (k”), (e’) scale bar = 15 µm. Abbreviations: AC, anterior commissure; DF, dendritic field; IN, interneuron; M1, primary motor cortex; MSN, medial septal nucleus; S2, secondary somatosensory cortex. See also Figures S1 and S2.