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来源：百度知道 编辑：UC知道 时间：2024/05/16 19:55:08
· AP not necessary for release of neurotransmitter, only facilitate necessary depolarization
· For non-spiking neurons release of neurotransmitter proportional to degree of depolarization, with even slight fluctuations having significant effect graded transmission,
· release in spiking cells is also graded to as indicated by presynaptic inhibition and by effects of experimental reduction in size of AP
· at some synapses both graded transmission and triggered release occur, for taste cells low level stimulation induces graded release, high level stimulation triggers AP
Chemistry of neurotransmitters
Hard to determine whether particular chemical serves as neurotransmitter at given synapse because synapses are not readily accessible for experimentation
Four criteria for identification of substance as neurotransmitter:
1. 1) must be synthesized in neuron from which released
· biochemical techniques used to demonstrate enzymatic pathways
· For non-spiking neurons release of neurotransmitter proportional to degree of depolarization, with even slight fluctuations having significant effect graded transmission,
· release in spiking cells is also graded to as indicated by presynaptic inhibition and by effects of experimental reduction in size of AP
· at some synapses both graded transmission and triggered release occur, for taste cells low level stimulation induces graded release, high level stimulation triggers AP
Chemistry of neurotransmitters
Hard to determine whether particular chemical serves as neurotransmitter at given synapse because synapses are not readily accessible for experimentation
Four criteria for identification of substance as neurotransmitter:
1. 1) must be synthesized in neuron from which released
· biochemical techniques used to demonstrate enzymatic pathways
美联社没有必要递质释放, 只需要方便极化非扣球释放神经递质去极化程度成正比, 小幅波动具有重大影响,甚至与分级传输 扣球细胞释放也是分级显示突触来抑制和减少规模效应实验鸭约释放,引起突触传递均发生渐变, 住宅品味低水平刺激细胞诱导分级发放喜 刺激生长激素水平牵动鸭化学递质很难断定为特定化学递质在突触给予突触并不容易,因为实验鉴定内容为四化递质: 1. 1)必须由神经释放生化合成技术展示酶法合成所需疑似神经通路1. 2)必须从它储存在神经解剖学释放免疫标记技术,如可用于确定分配一个疑似发射机 当前,尤其是否在突触终端1. 3)必须脱离这些神经终端可以搜集和确定,由怀疑神经突触附近活跃1. 4)当外部应用、 行动必须模仿自然神经递质ionophoresis可推定适用于突触后细胞已知药物阻断神经递质结合自然、 还应蟹块效应充分运用化学电池的应用测试很少播出特别突触, 但对许多不同的应用技术允许多突触物质被确认为神经递质化学基于好的证据大部分已知或怀疑递质分为三类1. 1)蛋白质的氨基酸积木, 具备了酸胺(含尿素)化工集团是许多神经递质谷氨酸的兴奋性氨基酸神经递质大多数脊椎动物大脑和神经肌肉接头兴奋也兴奋递质天冬氨酸昆虫γ-氨基丁酸(GABA)、甘氨酸抑制