D amphetamine sulfate

To record the behavioral and electrophysiological effects of pharmacological treatments, animals were placed in a round open field arena and the implant was connected to the amplifier boards. After ~60 min of baseline recording, the animal was intraperitoneally injected with LSD (lysergic acid diethylamid, 0.3 mg/kg, Lipomed AG, Switzerland), DOI (2,5-dimethoxy-4-iodoamphetamine hydrochloride, 2 mg/kg, Lipomed AG, Switzerland), ketamine (Ketaminol, 25 - 50 mg/kg, Intervet AB, Sweden), PCP (phencyclidine hydrochloride, 5 mg/kg, Lipomed AG, Switzerland) or amphetamine (d-amphetamine sulfate, 4 mg/kg, Tocris, UK) and recorded for another 60-120 minutes. Data were averaged over -35 to -5 min for baseline measurements and 30 to 60 minutes for on-drug measurements (relative to drug injection). For each animal, the experiment was repeated with a different drug in a pseudorandomized order (in total 18 LSD, 9 DOI, 27 ketamine, 7 PCP, and 10 amphetamine experiments) after a washout period of at least 24 hours (the median washout period was 4 days; see Fig. 1a and Table S5).

Testing for rotational asymmetry, induced by D-amphetamine sulfate (3.5 mg/kg i.p., Tocris Biosciences), was conducted 4 weeks after 6-OHDA administration to confirm motor deficits in unilateral lesioned rats. All animals displaying a functional deficit (>300 rotations in 60 min) were ranked in order of the percentage rotational asymmetry and evenly distributed across the four treatment groups: (i) Lesion only (subsequently referred to as Lesion), (ii) Lesion + GCV (GCV), (iii) VM progenitor cell graft (Cells), (iv) Cells + GCV administered from 5 to 13 weeks (Cells + GCV), (v) Cells + GCV administered from 14 to 22 weeks (referred to as Cells+ late GCV). To assess functional integration of transplanted cells, behavioural testing was repeated at 24 weeks after grafting.

The locomotor behavior of 11–12-week-old male or female Syt1 cKO^DA mice was recorded using an infrared actimeter (Superflex sensor version 4.6, Omnitech) using the Fusion software (v5.6 Superflex Edition, RRID:SCR_017972). A chamber partition was used to measure two mice at a time. Subjects were not given time to acclimate and spent a total of 60 min in the chamber with the following protocol: the first 20 min was used to record basal locomotion, while the following 40 min was used to record locomotion after saline or drug administration (i.p.). Drug treatments correspond to a single dose of cocaine hydrochloride at 20 mg/kg (Medisca, cat# 53-21-4, Canada) or D-amphetamine sulfate at 5 mg/kg (Tocris, 2813, UK) at doses known to increase locomotion^{87 (link),88 (link)}. SCH23390-HCl (Sigma, D-054, Canada) at 50 µg/kg, quinpirole-HCl at 0.2 mg/kg (Sigma, Q-102, Canada) and raclopride l-tartrate at 1 mg/kg (Sigma, R-121, Canada) were also used at selected high doses known to reduce locomotion in the open field^{89 (link)–91 (link)}. Each drug was diluted into 0.9% sodium chloride saline solution (Halyard, #cat 116). For each drug tested, a different cohort of mice was used. Results are presented as the mean of the traveled distance.