Zhou T L, Tamura R, Kuriwaki J, Ono T
Department of Physiology, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Sugitani, Japan.
Hippocampus. 1999;9(3):220-34. doi: 10.1002/(SICI)1098-1063(1999)9:3<220::AID-HIPO3>3.0.CO;2-E.
The septal complex, having close and reciprocal connections with the hippocampus, is known to play an important role in learning and memory. Anatomically, the septal complex is divided into the medial and lateral areas (MS and LS). In the present study, in order to elucidate functional differences between the MS and LS, we recorded single unit activity in the MS or LS and electroencephalogram (EEG) in the hippocampus simultaneously while the rats performed the following 2 spatial tasks in an open-field chamber. In task 1, the rat received rewarding intracranial electrical stimulation (ICES) when it entered in a reward place that was set randomly in the open field in each trial. In task 2, the rat received rewarding ICES when it alternately visited two fixed reward places in the open field. Unit activity was analyzed in relation to the pattern of hippocampal EEG, and rat's location, locomotion direction and locomotion speed in the spatial tasks. A total of 47 neurons were recorded in the septal complex (MS, 19; LS, 28). The majority of neurons with activity correlated with hippocampal EEG were found in the MS (14/19). All of the neurons with place-related activity (an increase in unit activity when the rat was in a specific location in the open field) were found in the LS (n = 15). The majority of neurons with direction-related activity were found in the LS (18/23). Twenty-one neurons displayed speed-related activity (MS, 9; LS, 12). The present results indicate that (1) the MS is directly involved in the formation and control of hippocampal EEG patterns, and (2) the LS is important for the processing and integration of spatial information in the environment.
隔区复合体与海马体有着紧密的相互连接，已知其在学习和记忆中发挥重要作用。从解剖学角度来看，隔区复合体可分为内侧和外侧区域（MS和LS）。在本研究中，为了阐明MS和LS之间的功能差异，我们在大鼠于旷场箱中执行以下两项空间任务时，同时记录了MS或LS中的单个神经元活动以及海马体中的脑电图（EEG）。在任务1中，大鼠进入每次试验在旷场中随机设置的奖励位置时，会接受颅内电刺激奖励（ICES）。在任务2中，大鼠交替访问旷场中的两个固定奖励位置时，会接受ICES奖励。结合海马体EEG模式、大鼠在空间任务中的位置、运动方向和运动速度，对神经元活动进行了分析。在隔区复合体中共记录了47个神经元（MS，19个；LS，28个）。与海马体EEG相关的活动神经元大多数存在于MS中（14/19）。所有与位置相关活动的神经元（大鼠在旷场中的特定位置时单位活动增加）均存在于LS中（n = 15）。与方向相关活动的神经元大多数存在于LS中（18/23）。21个神经元表现出与速度相关的活动（MS，9个；LS，12个）。目前的结果表明：（1）MS直接参与海马体EEG模式的形成和控制；（2）LS对于环境中空间信息的处理和整合很重要。
