神经生物学脑的节律与睡眠

脑的功能状态
觉醒 非快速眼动睡眠（慢波睡眠）：可运动躯体中的怠速运行的脑 快速眼动睡眠：麻痹躯体中的活跃而幻觉的脑
睡眠周期
存在4阶段non-REM和 REM睡眠的周期 Non-REM占睡眠的75% ，REM占25% 周期平均90分钟 Non-REM由长变短， REM由短变长 睡眠后期很少进入第4阶 段的non-REM睡眠 Non-REM和REM至少30 分钟间隔
脑的节律与睡眠
周煜东
浙江大学神经科学研究所 Academic year: 2013-2014 Spring-Summer terms
Outline
1. 脑电图 2. 睡眠与觉醒 3. 昼夜节律
Hans Berger 与EEG的发现
从telepathy到EEG的发
EEG电极位置
A, 耳(auricle); C, 中央(central); Cz, 顶点 (vertex); F, 前额部(frontal); Fp, 额极(frontal pole); O, 枕部(occipital); P, 顶部(parietal); T, 颞侧(temporal).
Beta(β)
14 - 30
20
Theta(θ)
4–7
Above 50
Delta(δ)
2–4
Above 50
同步化产生
双神经元振荡
单神经元振荡
丘脑节律驱动皮层节律
异常EEG节律：癫痫
Outline
1. 脑电图 2. 睡眠与觉醒 3. 昼夜节律
睡眠
Sleep is a readily reversible state of reduced responsiveness to, and interaction with, the environment. 对环境反应和与环境互动显著降低的可随时逆转的状态
Beta波
Characteristics: -frequency: 14-30 Hz -amplitude: 2-20 µV The most common form of brain waves. Are present during mental thought and activity
Theta Waves
Characteristics: -frequency: 4-7Hz -amplitude: 20-100µV Believed to be more common in children than adults Walter Study (1952) found these waves to be related to displeasure, pleasure, and drowsiness Maulsby (1971) found theta waves with amplitudes of 100µV in babies feeding
Different types of brain waves in norபைடு நூலகம்al EEG
Rhythm Alpha(α) Frequency (Hz) 8 – 13 Amplitude (uV) 50 – 100 Recording & Location Adults, rest, eyes closed. Occipital region Adult, mental activity Frontal region Children, drowsy adult, emotional distress Occipital Children in sleep Slow-wave sleep
睡眠的EEG节律变化
梦
Non-REM梦：时间较短，视觉内容少，少有情绪内 容，多是概念性的，常与日常生活事件相关。 梦游，梦话 REM梦：时间相对长，主要是视觉的，也有情绪的 ，与日常经历的时间相对无关，生动的，怪诞的。 清醒梦
我们能控制梦境吗？
Lucid dreams 清醒梦
测量一对电极间的差异信
EEG的产生
只有许多细胞的贡献才能使在头皮上记录的信号大到被识别记
思考问题
突触活动在皮层深层，记录到的EEG极性如何？ 动作电位的幅度要比突触后电位大，为什么EEG的主要贡献是后者？ 抑制性突触后电位能被EEG记录到吗？
神经元同步活动可使EEG信号增大
脑电节律
Delta Waves
Characteristics: -frequency: 0.5-3.5 Hz -amplitude: 20-200µV Found during periods of deep sleep in most people Characterized by very irregular and slow wave patterns Also useful in detecting tumors and abnormal brain behaviors
Gamma Waves
Characteristics: -frequency: 32-100Hz -amplitude: 3-5µV Occur with sudden sensory stimuli, sensory binding Conscious attention meditation
Alpha波
Characteristics: - frequency: 8-13 Hz - amplitude: 20-60 µV Easily produced when quietly sitting in relaxed position with eyes closed (few people have trouble producing alpha waves) Alpha blockade occurs with mental activity -exceptions found by Shaw(1996) in the case of mental arithmetic, archery, and golf putting