PHYL 2041 Lecture Notes - Lecture 4: Apposition, Motor Neuron, Neurotransmitter Transporter
19 Sep 2018
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Document Summary
Synapse are specialized zone of contact at which one neuron communicates with another. Some numbers: neurons in the human brain: 1011-1012, the average neuron receives 1000 synapses (large range). Number of synapses in the human brain: 1015-1016. Electrical synapses are junctions between neurons permitting direct, passive flow of electrical current (ions flow) Chemical synapses are junctions between neurons that communicate via the secretion of neurotransmitters; which retranslates into an electrical current. Electrical synapses are gap junctions: gap junctions at sites of close (3 nm) cell apposition, precisely aligned, paired channels made of connexions. Gap junctions are points of integral membrane contact. Gap junction allows two cells to connect to each other via gap channels (ions channels joined and aligned via adjacent cell). Each channel is make out of 6 subunits which are then made up of connexins. Gap junctions at formed between 2 cells and come in very close proximity.
