Wistar rat

Cocaine-exposure experiments were performed in duplicate, within a total of 36 animals originating from these 2 identical and independent experiments 8 wk apart. In both experiments, 18 adult (110-115 d old) male Wistar rats (Janvier Laboratories) weighing on average (6SD) 500 6 40 g were used. Additionally, a matched control group was used to control for cocaine-independent effects. Because sucrose induces homogeneous self-administration behavior, we anticipated a low level of variance in the control group. Therefore, a smaller number of animals, that is, 6, were included in this group. On arrival at our facility, all rats were housed individually under an inversed 12-h light-dark cycle. With free access to water and 20 6 1 g of food (Ssniff) per day, a stable body weight was maintained. At least 7 d before the self-administration sessions, the rats had a polyurethane 22-gauge catheter (Instech Laboratories) inserted through the femoral vein in the cranial direction for 7 cm. A vascular access button was mounted between the shoulder blades using a polyethylene terephthalate mesh. The research protocol was approved by the Animal Ethics Committees of the University of Leuven (P156/2013) and was performed in accordance with the guidelines of the European Ethics Committee (decree 86/609/EEC).

Eight-week-old male Wistar rats (Janvier Labs, Saint-Berthevin, France) were kept at the animal facility of the University Jaume I. The procedures followed directive 86/609/EEC of the European Community on the protection of animals used for experimental and other scientific purposes. The experiments were approved by the Ethics Committee of the University Jaume I (approval number 2014/VSC/PEA00209).
The animals were maintained on a 12 h:12 h light-dark cycle and housed in pairs to reduce stress due to social isolation. Rats were divided randomly into four experimental groups: SD, control animals fed the standard rodent diet (Ssniff, Soest, Germany); SD-ABA, animals fed standard diet supplemented with ABA (Fernandez-Rapado, Spain) in their drinking water (20 mg/L); HFD, animals fed an HFD (5736 kcal/kg, Ssniff) and HFD-ABA, animals fed an HFD and that had ABA in their drinking water (20 mg/L).
We have used ABA concentration as described [40] (link). The four groups were fed ad libitum for 12 weeks.

All animal studies were performed according to approved institutional protocols. Adult male Wistar rats (300-350 g; Janvier Labs, Le Genest Saint-Isle, France) were randomly divided into control, control-treated, PH, and PH-treated groups (n = 4-12 rats per group). PH was induced by either exposing rats to CH in a controlled hypobaric chamber (380 mm Hg) for 28 days, or with a single intraperitoneal MCT injection (60 mg/kg; Sigma-Aldrich). In both preventive and curative protocols, control-treated and PHtreated groups received either nonrelevant antibodies (10 mg/kg intraperitoneally, normal rabbit polyclonal IgG; Millipore, Molsheim, France) or rabbit polyclonal anti-NGF blocking antibodies (10 mg/kg intraperitoneally; Millipore). The online supplement provides further details.