going before another in time or order I'd like to follow up on an antecedent question from another reporter Synonyms previous, anterior, foregoing, former, precedent, preceding, priorRelated Words advance, early, premature; earliest, first, inaugural, initial, maiden, original, pioneer; preexisting; introductory, preliminary; erstwhile, whilomNear ...
Neurotransmitters are formed in a presynaptic neuron and stored in small membrane-bound sacks, called vesicles, inside this neuron. When this neuron is activated, these intracellular vesicles fuse with the cell membrane and release their contents into the synapse, a process called exocytosis.
At rest, neurotransmitter-containing vesicles are stored at the terminal of the neuron in one of two places. A small number of vesicles are positioned along the pre-synaptic membrane in places called active zones..This is where neurotransmitter release occurs.Most vesicles, however, are held close to these zones, yet further from the membrane itself until they are needed.These vesicles are held in place by Ca2+-sensitive vesicle membrane proteins (VAMPs), which bind to actin filaments, microtubules, and various other elements of the cytoskeleton.ocking is the process by which the vesicle and the pre-synaptic membrane line up in a position that will allow them to fuse easily. Fusion then takes place, in which the vesicle membrane and the pre-synaptic membrane connect to form a small opening, a pore, connecting the lumen of the vesicle with the synaptic cleft.