NROB60H3 Lecture Notes - Lecture 7: Chemical Synapse, Neurotransmitter Receptor, Axon Terminal
Document Summary
Synaptic transmission: the process of information transfer at a synapse. Direction of information flow: in one direction: neuron to target cell, first neuron = presynaptic neuron, target cell = postsynaptic neuron. Electrical synapses: widespread throughout brain but rare, narrow cleft (gap junction) 2-4 nm, cells are said to be electrically coupled . Flow of ions from cytoplasm to cytoplasm: membranes have large channels. Connexon - formed by 6 connexins: transmission along synapses resembles conduction along axon, work with little time delay, frequently found in neural circuits such as escape behaviour. Gray"s type i: asymmetrical, excitatory: membranes are different thicknesses. Principles of chemical synaptic transmission: basic steps. Amino acids and amines neurotransmitters are small organic molecules containing nitrogen: stored and released from synaptic vesicles. Peptide neurotransmitters are large molecules that are stored and released from secretory granules. Different neurotransmitters are synthesized in different ways. Neurons contain specific enzymes that synthesize specific neurotransmitters. Enzymes are located in specific areas of the neuron.
