20220603_MLE_03_04_Experiment 3699_2022-06-03_19-38-32_0000665

Male rats were purchased from Janvier Laboratories at 6 weeks of age. Upon arrival, rats were housed in pairs that were conserved throughout the experiment. After one week of acclimation, we identified each individual with a subcutaneous Radio Frequency Identification (RFID) tag (APT12 PIT tags; Biomark, Inc., Boise, The United States of America) inserted under gas anaesthesia (Isoflurane) with local analgesia (Lidor 20 mg/ml, with 40μl/10g). RFID tags were positioned in the lower part of the left flank. Rats were allowed to recover for at least ten days. We continuously recorded dyadic interactions between two familiar male rats of the same age (10–12 weeks of age). Recordings started between 03:00 and 04:00 PM and lasted undisturbed 47h long, that is, two days and nights minus 1h for cleaning in between two recording sessions. We coupled the Live Rat Tracker (LRT) system (https://micecraft. org/lmt; version 931) with the Avisoft Ultrasound Gate 416 (300kHz sampling rate, 16-bit format; trigger: level of this channel; pre-trigger: 1s; hold time: 1s; duration: >0.005s; trigger event: 2% energy in 25–125kHz with entropy <50%; Avisoft Bioacoustics, Glienecke, Germany) connected to a CM16/CMPA microphone (Avisoft Bioacoustics, Glienecke, Germany). LRT and Avisoft systems were synchronised.实验所用雄性大鼠购自Janvier Laboratories，购得时龄为6周。大鼠抵达实验室后即成对饲养，且该饲养组合在整个实验过程中保持不变。经过1周的适应期后，采用异氟烷（Isoflurane）吸入麻醉联合局部镇痛（使用20mg/ml的利多卡因，剂量为40μl/10g体重），于皮下植入射频识别（Radio Frequency Identification, RFID）标签（APT12 PIT标签；Biomark公司，美国博伊西）以标记每只个体，标签植入位置为左侧腹下部。大鼠术后至少恢复10天。本研究持续记录两只同周龄（10~12周龄）熟悉雄性大鼠之间的成对互动行为。录制于每日下午3时至4时之间启动，以无干扰模式持续录制47小时，即覆盖两个完整昼夜，期间预留1小时用于两次录制周期间的清洁作业。本研究将活体大鼠追踪（Live Rat Tracker, LRT）系统（https://micecraft.org/lmt；版本931）与Avisoft Ultrasound Gate 416超声采集设备相连，该设备外接CM16/CMPA型麦克风（Avisoft Bioacoustics公司，德国格利内克）；其中超声采集设备参数为：采样率300kHz，16位格式，触发条件为该通道电平，预触发时长1s，保持时长1s，有效时长>0.005s，触发事件为25~125kHz频段内能量占比2%且熵值<50%。LRT系统与Avisoft超声采集系统实现了同步对接。