2005-01-15 14:24:03暈炫

neurophysiology

Component of neurotransmitter
财 Serotonin:5-HT
财 Dopamine derivative:Tyrosine
财 Substance P:polypeptide

老花眼:decreased elasticity of lens

眼睛的感覺細胞
1. Photoreceptor
财 Photoreceptor cell → outer segment → disk → 含rhodopsin = Vit A
(retinal, 主要的感光原件) + Opsin
财 Cone:主要在fovea
财 Rod:分布在fovea以外區域
2. Bipolar cell
3. Ganglionic cell:產生action potential

Light and dark
财 Rod:Dark → Na influx → deplorization → [cGMP]↑
Light → hyperpolarization → [cGMP]↓
财 Retinal:Light:Cis → Trans
Dark:Trans → Cis
财 Light adaptation:degeneration of rhodopsin
Dark adaptation:generation of rhodopsin

Cochlear上的basal membrane:負責聽覺
财 Sound wave → hair cell → transformation(變形) → K influx
财 底部較硬、窄、high frequency ;頭部較軟、寬、low frequency
财 Inner cell:重要 outer cell:負責amplification

Motor cortex:精細的臉,手占了大部分
Babinski's sign:測得是corticospinal pathway

Motor cortex:
财 愈中間的,多半是trunk上的muscle,與position相關,多半是兩側的
财 愈旁邊的,多半是distal的muscle,多半是負責對側的動作
财 Extensor與姿勢相關,所以負責的區域多在motor cortex靠中間

運動的產生
Direct pathway:corticospinal pathway
Indirect pathway:vestibulospinal, reticulospinal pathway

Pontinoreticular pathway:anti-Gravity → 姿勢相關、extensor相關

小腦:
财 Purkinje cell:負責output,會接deep cerebellar nu.(唯一出口)
财 Climbing fiber:直接跟purkinje cell產生synapse
财 主要負責平衡,協調的功能,受損影響的是同側的運動 ∵ cerebellum dentate
nu. → 交叉 → thalamus → cortex → corticospinal tract → 交叉 → 運動

Basal ganglinon:其中的substantia nigra跟parkinsonisom有關
财 Substantia nigra → 抑制 Globus pallidus internal capsule (GPI)
GPI → 抑制大腦動作
财 Direct pathway:(-)(-):促進
财 Indirect pathway:(-)(-)(-):抑制
财 所以substantia nigra活化時 → 負負得正 → 幫助大腦大動
财 所以,parkinsomism的病人會Hypokinesia
财 Huntinton's disease是indirect pathway,所以是Hyperkinesia

Vision
财 Primary cortex:光的強弱
财 Secondary cortex:圖形
财 Association area:意義

Central sulcus前:primary motor cortex
Central sulcus後:somatosensory cortex

大腦的association area
1. parieto-occipito-temporal:language, intelligence
2. pre-frontal area:memory
3. Limbic:emotion

Wernicke's area:somatocsensory下:所以是負責language comprehension,對於
慣用右手者,左側的wernick's area較大
Broca's area:primary motor下:所以是負責說話的

Hippocampus:memory
Limbic system:包含了hypothalamus,關於hypothalamus
财 Hypothalamus也算是ANS的一部分
财 Osmotic receptor:在anterior hypothalamus
财 Satiety center:Ventromedial area(VM):所以若VM處的nucleus壞了,病人
就不會餓了,然後變超瘦的?
财 Hunger center:在lateral area

EEG:record postsynaptic potential, mainly from cortex

Nuclesu accumbence:rewarding center:大部分的毒品都是作用在此處
Mesolimbic dopamine pathway:跟addiction有關

Memory formation:
财 LTP, long term potentiation
财 Glutamate:最重要的neurotransmitter
财 Glutamate → 打開Mg block的NMDA receptor → Ca influx → NO release
(LOOP)
财 如果這個刺激太強了,會誘使細胞產生transcription → protein formation →
plasticity(變形) → dendrite上面會出現新的synpase