MEDICAL PHYSIOLOGY

Detailed explanation-1: -Synaptic vesicles (SVs) are small, electron-lucent vesicles that are clustered at presynaptic terminals. They store neurotransmitters and release them by calcium-triggered exocytosis. SVs are made locally at the terminals and are regenerated after exocytosis.

Detailed explanation-2: -Neurotransmitters are released from synaptic vesicles in presynaptic neurons in response to neural activity, diffuse across the synaptic cleft, and bind specific receptors in order to bring about changes in postsynaptic neurons.

Detailed explanation-3: -Molecules of neurotransmitters are stored in small “packages” called vesicles (see the picture on the right). Neurotransmitters are released from the axon terminal when their vesicles “fuse” with the membrane of the axon terminal, spilling the neurotransmitter into the synaptic cleft.

Detailed explanation-4: -Synaptic vesicles undergo a membrane-trafficking cycle in the presynaptic nerve terminal that prepares them for neurotransmitter release.

Detailed explanation-5: -Neurotransmitters are stored in different types of synaptic vesicles. Glutamate, GABA, glycine, and ACh are stored in small, clear vesicles, and monoamines are stored in intermediate-sized, dense-core vesicles. Both types of vesicles are loaded with the neurotransmitter at the nerve terminal.