Conditioned place preference D1-cre. Chemogenetic inhibition during retrieval

Figure 4E. Mice strain: D1- Cre/WT Viruses- AAV2-hSyn-DIO-hM4Di Coordinates:±2.82,1,-3.69 WT;#n=7 hM4Di/CNO;#n=5 Apparatus: Each place conditioning apparatus consists of an open field enclosed in separate light- and sound-attenuating chambers. General activity and location in the open field was monitored by video recording. The floor of the open field consisted of interchangeable halves made of one of two textures. The combination of floor textures was selected on the basis of calibration studies observing that mice spend an average of about 50% time on each floor type during preference tests. Thus, the apparatus is "unbiased". Specifically, the floors are either of a rough "crushed ice" texture, coupled with walls on which appear black dots vs. a smooth floor texture coupled with walls on which appear vertical black lines. Prior to and following each session the open field and floors was cleaned using a solution of 5% virusolve. Procedures: An unbiased conditioning procedure consists of the following phases: Handling: 30-min sessions. Pre-conditioning bias test: a single 20 min test session is conducted during which mice are allowed to freely explore the open field with half of the arena containing the "crushed ice" floor and dots walls and half of the arena containing the "smooth" floor and straight lines walls. Conditioning: 3 days 2 session/day. Mice are randomly assigned to one of two groups, pairing cocaine (10 mg/kg IP) to either the ‘crushed ice’ or ‘smooth’ contexts, while saline conditioning (10 ml/kg) occurred on the opposite context. On all sessions, mice have access to the entire apparatus with the same floor and walls type on both sides. Post-conditioning bias test: identical to Pre-conditioning. Each CPP experiment was performed on a different group of mice, where Pre-conditioning and Post-conditioning bias test was measured within the same group of mice. For chemogenetic inhibition during conditioning, CNO (10 mg/kg, IP) was injected 30min prior to cocaine. For chemogenetic inhibition during retrieval, mice went through the regular CPP protocol, including a retrieval test, following which they were subject to another conditioning day and finally, to an additional test 30min after CNO (10 mg/Kg, IP) injection.图4E。 小鼠品系：D1-Cre/WT；病毒载体：AAV2-hSyn-DIO-hM4Di；注射坐标：±2.82,1,-3.69；野生型（WT）组：n=7；hM4Di/CNO组：n=5。 实验装置：每台位置条件化装置均设有一处开放场地，该场地被置于独立的隔音避光舱内。开放场地的整体活动与空间位置通过视频录制进行监测。开放场地的底板由两种不同质地的可拆分半区组成。底板质地的组合经过校准实验验证：在偏好测试中，小鼠在两种底板类型上的平均停留时间均约为50%，以此确保装置无偏倚性。具体而言，两种环境分别为：① 粗糙“碎冰”质地底板，搭配带有黑色圆点的侧壁；② 光滑质地底板，搭配带有垂直黑色线条的侧壁。每次实验阶段前后，均使用5% virusolve溶液对开放场地及底板进行清洁。 实验流程：无偏倚条件化实验流程包含以下阶段： 1. 适应训练：单次时长30分钟。 2. 预条件化偏好测试：开展单次20分钟的测试阶段，小鼠可自由探索开放场地，场地的一半区域为“碎冰”质地底板搭配圆点侧壁，另一半区域为光滑底板搭配垂直直线侧壁。 3. 条件化训练：为期3天，每日开展2次训练。将小鼠随机分为两组：一组将可卡因（10 mg/kg，腹腔注射）与“碎冰”环境配对，另一组将可卡因与“光滑”环境配对，而生理盐水（10 ml/kg）则在另一侧环境中进行给药。所有训练阶段中，小鼠可自由接触整个装置，且装置两侧的底板与侧壁类型保持一致。 4. 后条件化偏好测试：流程与预条件化偏好测试完全一致。 每项条件性位置偏好（CPP）实验均使用独立的小鼠队列，且同一队列的小鼠会依次完成预条件化与后条件化偏好测试。 若需在条件化训练阶段实施化学遗传抑制，则于可卡因给药前30分钟腹腔注射CNO（10 mg/kg）。 若需在复现阶段实施化学遗传抑制，则小鼠先完成常规CPP实验流程（包含复现测试），随后再接受1天的条件化训练，最终在CNO（10 mg/kg，腹腔注射）给药30分钟后开展额外测试。