Ar a014418

Activation of PI3K was achieved by a transduction peptide (PTD4-PI3KAc) with the following sequence: YARAAARQARAGSDGGpYMDMS [29 (link),46 (link)–48 (link)]. This is a cell membrane permeable phosphopeptide composed of a transduction domain of the tat family [48 (link)] fused to a SH2 interacting domain that allows the activation of the class I PI3K independently from tyrosine kinase dimerization [29 (link),48 (link)–49 (link)]. Peptides were purchased either from GenScript (NJ, USA) or BioPeptide (FR). GSK3 inhibitors: SB-415286 and AR-A014418 [50 (link)–52 (link)] were from Tocris, UK (ref. 1617) and from Sigma, USA (ref. A3230), respectively.

All drugs were administered via intraperitoneal injection. 5-HT1A/B agonist RU24969 (Tocris Bioscience, Bristol, UK) was dissolved in saline (0.9% NaCl) and administered at 0 or 3 mg/kg (Experiments 1 and 3), 0 or 10 mg/kg (Experiments 2 and 4) or 0, 3, or 10 mg/kg (Experiment 5) at 5 ml/kg injection volume. Doses were selected based on previous studies demonstrating OCD-like behavior in this dose range [6 (link)–9 (link)] and to achieve a high and a more moderate dose [27 (link)]. The GSK-3 inhibitor SB216763 (Tocris Bioscience, Bristol, UK) was dissolved in 4% DMSO/15% Tween-80 in saline and injected at 20 ml/kg injection volume. SB216763 was administered at 0, 5, or 10 mg/kg based on previous studies demonstrating effects of SB216763 on relevant behavioral measures and the ability of SB216763 to block behavioral effects of other pharmacological compounds in this dose range [28 (link)–30 (link)]. GSK-3 inhibitor AR-A014418 (Tocris Bioscience, Bristol, UK) was dissolved in 4% DMSO/15% Tween-80 in saline and injected at 20 ml/kg injection volume. AR-A014418 was administered at 0, 10, or 20 mg/kg based on previous studies [31 (link),32 (link)]. SB216763 and AR-A014418 were used because they have high selectivity for GSK-3 inhibition, modulate 5-HT1BR signaling, and cross the blood-brain barrier [23 (link),33 (link)–35 (link)].