Xap044

Chronic application of the orthosteric-like mGlu7 antagonist XAP044 (Tocris Bioscience, Bristol, UK; Figure 1B) via s.c.-implanted Alzet^® micro-osmotic pumps (pumping rate: 0.11 µL/h, Alzet^®, Model 1004, Cupertino, CA, USA) connected to an i.c.v. infusion cannula (Brain Infusion Kit 3, Alzet^®, Cupertino, CA, USA) was initiated one week before starting the CSC paradigm (day 6) in order to establish a stable baseline receptor occupancy and was continued until the end of chronic stressor exposure (day 20). XAP044 was formulated as a solution in vehicle (VEH, 5% DMSO in Ringer’s solution, Merck; Darmstadt, Germany) to ensure a continuous substance release of 1 µM, 10 µM or 100 µM of XAP044. As reported by Peterlik et al. 2017 [23 (link)], the micro-osmotic pump was implanted s.c. in the abdominal region through a 1 cm long incision at the lower neck of the mouse under isoflurane anesthesia (Baxter, GmbH, Unterschleißheim, Germany) but additionally connected via a catheter to an i.c.v. infusion cannula. Animals were treated with painkiller (Buprenovet, s.c.; 0.05 mg/kg; Bayer Health Care AG, Leverkusen, Germany) and 100 µL of antibiotics (s.c., Baytril^®, 2.5% Bayer Health Care AG, Leverkusen, Germany). Wound treatment was conducted using betaisodona (Mundipharma GmbH, Limburg, Germany).