IMSUT & RCAST GCOE 特別セミナー
開催日時： 平成23年 2月 18日（金） 17:00～18:00
講師氏名： 新井 賢亮&s_comma; 学振特別研究員
講師所属： 理化学研究所 脳回路機能理論研究チーム
演 題： Spike-triggered averaging of the Local Field Potential in awake rat motor cortex (M1) reveals organizational principals of the local columnar circuit of M1
Understanding the brain requires many different approaches to elucidate the subject matter at hand. The high-level approach from psychophysical experiments have revealed what it is the brain actually does. On the other hand&s_comma; low-level works have revealed the machinery to explain how the brain actually computes and processes the information - how the brain does what it does. In this talk&s_comma; I approach the subject of the brain from the level of the circuit. I will introduce an experiment investigating the forelimb area (FL) of the motor cortex (M1) of awake&s_comma; behaving rats performing a task in which the rat must hold down a lever for more than 1 second&s_comma; and pull the lever back up to receive a water reward. Juxtacellular (cell-attached) recordings of neurons in layers 2/3 ~ 6 (100~1600 um below pia) of the motor cortex were made&s_comma; revealing neurons with various movement tuning profiles (neurons differentially active during specific phases of movement). In addition to juxtacellular recordings&s_comma; concurrent recordings were made from two tetrodes at 400 and 1200um&s_comma; and spikes from these probes were sorted offline&s_comma; revealing similar types of neurons as obtained from juxtacellular recording. Finally&s_comma; the local field potential (LFP) was also measured concurrently&s_comma; at depths ranging from 0 ~ 1200um in 150um increments. The LFP is thought to represent synchronized synaptic input into the local network. Analyzing the spikes and the LFP during movement of the lever reveals different characteristic relationships depending on the location of the cell and movement tuning. Further&s_comma; tetrode recordings allow multiple nearby neurons to be recorded at the same time&s_comma; and neurons recorded by this method suggest that cells that are close to each other and have similar movement tuning profiles are not necessary wired to the cortical network in the same way.