Key Difference – Chemical vs Electrical Synapse
Chemical and electrical synapses are specialized biological structures found in the nervous system; they connectneuronstogether and transmit signals across the neurons. The key difference between chemical and electrical synapse is their method of transmitting signals;chemical synapse pass signals in the form of chemical molecules called neurotransmitters while electrical synapse transmits signals in the form of electrical signals without the use of molecules.化学突触和电突触的结构由于作用方式而彼此略有不同。
A synapse can be defined as a structure mediating the transmission of signals from oneneuron到相邻的神经元。在神经系统中发现突触。它们可以传输电信号或化学信号。可以根据这种类型的信号将突触分为两种主要类型：电突触和化学突触。在突触中，交流两个神经元的近距离质膜to pass the signal accurately and efficiently. The neuron which sends the signal consists of the presynaptic end while the neuron receiving the signal consists of the postsynaptic end. These ends can be seen inaxon and dendrite/soma respectively.
Chemical synapse is a biological structure that can be found among two neurons or among a neuron and a nonneuronal cell and its main function is to communicate with each other via chemical messengers as shown in figure 01. These chemical messengers are known asneurotransmitters。Neurotransmitters are produced and packaged inside the smallvesicles称为突触囊泡。突触囊泡充满神经递质，并在突触前神经元的突触前末端积聚。当作用电位变化在突触前神经元膜中时，这些神经递质会被释放胞吞作用to a space calledsynaptic cleft。Once these neurotransmitters enter into the synaptic cleft, they bind with the specific receptors located on the surface of the postsynaptic neuron and give the information. This is the type of chemical signal transmission that occurs at the chemical synapse; thus, these structures are of utmost importance to connect the nervous system without collapse. Signal transmission through chemical synapse occurs in only one direction.
One organism contains a huge number of chemical synapse in its nervous system. An adult may have 1000 to 5000 trillion chemical synapses in the central nervous system. This number can vary with the age.
What is the difference between Chemical and Electrical Synapse?
|In chemical synapse, signal transmission happens through chemical molecules called neurotransmitters.||在电气突触中，信号传输以电信号的形式发生，而无需使用分子。|
|Modification of Signals|
|Signals are modified during the transmission.||传输过程中未修改信号。|
|Release of Signals|
|Neurotransmitters are released by exocytosis and diffused in the synapsis cleft and then are bound to receptors.||Electric signal pass via gap junctions.|
|Space between the pre and postsynaptic ends is larger.||Space between the pre and postsynaptic ends is very small.|
|Direction of Signal|
|Signal transmission happens only into one direction.||Signal transmission can happen in both directions.|
|Signal transmission requires energy. So it’s an active process.||信号传输发生而无需使用能量。因此，这是一个被动过程。|
|Speed of Transmission|
|Signal transmission happens at a moderate speed.||Signal transmission is extremely fast.|
摘要 - 化学与电突触
There are two main types of synapses called chemical and electrical synapses. Chemical synapse uses chemicals called neurotransmitters to transmit signals along the neurons and facilitates a unidirectional transmission. Electrical synapse uses an ionic current to transmit signals along the neurons and facilitates transmission in both directions. The space between two neurons in the chemical synapse is larger and is known as synaptic cleft. Neurotransmitters are diffused in the synaptic cleft till they find their specific receptors. Two neurons in the electric synapse physically connect with each other through gap junctions; hence, the space is very small.
1. Purves, Dale. “Chemical Synapses.”Neuroscience。第二版。美国国家医学图书馆，1970年1月1日。2017年2月6日
2.Purves, Dale. “Electrical Synapses.”Neuroscience。第二版。美国国家医学图书馆，1970年1月1日。2017年2月6日
3. Nicholls，J。G.和D. Purves。“在水ech的中枢神经系统中，单个感觉细胞与运动神经元之间的化学和电突触传播的比较。”The Journal of Physiology。U.S. National Library of Medicine, Sept. 1972. Web. 06 Feb. 2017