Nbi27914

A 5-HT_2C receptor agonist (WAY161503), a 5-HT_2C receptor antagonist (SB242084), and a CRF1 receptor antagonist (NBI27914) were purchased from Tocris Bioscience. Several hours before the start of the electrophysiological recordings, a microdialysis probe (CMA11/Microdialysis; 250 µm membrane diameter; 1 mm membrane length) was lowered vertically into the BLA, ipsilateral to the recording electrode, using the following coordinates: 2.5 mm caudal to bregma, 4.8 mm lateral to midline, 9.0 mm depth. The distance between the microdialysis probe and recording electrode was ~0.5 mm. Before each drug application, artificial cerebrospinal fluid (ACSF) was pumped through the microdialysis fiber for about 1 h at a rate of 5 µL/min to establish equilibrium in the tissue. The microdialysis probe was connected to an infusion pump (Harvard) using PE-50 tubing. The ACSF contained (in mM) 125.0 NaCl, 2.6 KCl, 2.5 NaH2PO4, 1.3 CaCl2, 0.9 MgCl2, 21.0 NaHCO3, and 3.5 glucose oxygenated and equilibrated to pH ± 7.4. Drugs were dissolved in ACSF on the day of the experiment at a concentration of 100 times that was predicted to be needed based on data from our previous studies [36 (link),48 (link),61 (link),91 (link),92 ] and data in the literature [93 (link),94 (link),95 (link)]. Drugs were administered into the BLA at a rate of 5 µL/min.

Drug administration began between 8:30 and 9:30 a.m. VacA at doses of 3 and 30 nmol/kg bw in 100 µl of Tris-buffered saline (TBS) (60 mM Tris-HCl buffer, pH 7.7, containing 0.1 M NaCl) or TBS alone as the vehicle was IP administered to mice. VacA at doses of 0.06, 0.18, and 0.6 pmol/kg bw in 2 µl of ACSF or ACSF alone as the vehicle was administered via the ICV route to mice. To assess the contribution of the CRF receptors to VacA-induced behaviors, the mice were administered the CRF2 receptor antagonist antisauvagine-30 at a dose of 120 nmol/kg bw (Tocris Bioscience, Abingdon, UK) in 2 µl of ACSF, the CRF1 receptor antagonist NBI27914 at a dose of 400 nmol/kg bw (Tocris Bioscience) in 2 µl of a mixture of 80% dimethyl sulfoxide and 20% ACSF^{53 (link)}, or each vehicle control alone via the ICV route 5 min after the ICV administration of VacA. In chronic ICV-administered male Sprague-Dawley rats, VacA in ACSF was infused via the ICV route at a dose of 0.12 pmol/day.