PMC

(a) Full-scan mass spectrum of colchicine; (b) Full-scan mass spectrum of scopolamine hydrobromide; (c) MRM chromatogram of blank plasma; (d) MRM chromatogram of colchicine and scopolamine hydrobromide. The rentention time of colchicine and scopolamine hydrobromide was 3.7 min and 1.8 min, respectively.

The study 2 blocked experimental design reflecting infusion series and assessment sessions for the 2 randomized patient groups. P/S indicates placebo followed by scopolamine hydrobromide; S/P, scopolamine followed by placebo.

Mean Montgomery-Asberg Depression Rating Scale (MADRS) scores from study 1 as assessed immediately before and in the first evaluation after infusions of placebo and each of 3 doses of scopolamine hydrobromide. Error bars represent SE. *Significantly different from baseline (P=.002) and from preadministration of 4.0 μg/kg of scopolamine (P=.02).

Muscarinic receptor blockade disrupts object memory updating in the PROMM task. (a) Intraperitoneal injections of scopolamine hydrobromide or saline were given 20 min before the reactivation phase (n = 24). (b) Rats in the same alternate context condition that received pre-reactivation scopolamine displayed greater object exploration in the test phase, similar to the different alternate context conditions, compared to the vehicle/same alternate context condition. **p < 0.01, ***p < 0.001.