Fig. 2
Characterization of the phenotype of Lmx1a/b double conditional mutant mice at P1. a Schematic representation of coronal section of mouse brain at the midbrain level at post-natal day 1 (P1). Dashed line indicates the delimitation of the pictures shown in b. Distribution (b) and number (c) of mDA neurons in the midbrain were not different between controls and Lmx1a/b cKO at P1 (n = 4, two-tailed unpaired t test, p = 0.8134). d, e Schematic representations of axonal innervation in the striatum in control and Lmx1a/b cKO mice brains at P1. f, g Representative confocal images of control and Lmx1a/b cKO mice brain sections showing a loss of dopaminergic innervation in dorso-posterior striatum for Lmx1a/b cKO mice (TH in green and DAPI in blue). h, i Optical density measurements of TH axons in the striatum. Graphs in (i) show the ratio of TH intensity in dorsal vs. ventral striatum (n = 7, two-tailed unpaired t test, p (Ant D) = 0.0483, p (Cent D) = 0.3398, p (Cent V) = 0.9596, p (Post D) = 0.0003, p (Post V) = 0.5914, p (Ant D/V) = 0.0526, p (Cent D/V) = 0.1863, p (Post D/V) ≤ 0.0001, Mann–Whitney U, p (Ant V) = 0.1649). j Light-sheet scans of the TH immunostaining in the striatum of iDISCO-cleared brains from control and Lmx1a/b cKO mice. The panels show single optical planes in coronal and reconstructed sagittal and horizontal planes showing the lack of TH axons in the dorsal striatum of the Lmx1a/b cKO mice brains. Dotted lines delineate the border of the striatum. k Schematic representation of the location of electrophysiological recordings in the striatum. l, m Analysis of the frequency of miniature excitatory post-synaptic currents (mEPSC) and miniature inhibitory post-synaptic currents (mIPSC) in dorsal and ventral striatum (dorsal striatum: n = 9 cells for controls and n = 11 cells for Lmx1a/b cKO, Mann–Whitney U, p (mEPSC) = 0.0078; p (mIPSC) = 0.0275; ventral striatum: n = 9; two-tailed unpaired t test; p (mEPSC) = 0.0408; p (mIPSC) = 0.0444). Scale bars: 250 µm for (b), (f), (g) and 500 µm for (j). D, dorsal; L, lateral; N.S., not significant; Str, striatum; V, ventral
