Fast neurotransmitters

Table 3.1 Fast neurotransmitters in the central nervous system...

Jonas, P, Bischofberger, J and Sandkuhler, J (1998) Corelease of two fast neurotransmitters at a central synapse. Science 281 419-424. 

Despite its wide use and versatility, electrophysiological approaches also possess several caveats. First, this form of detection is limited to fast neurotransmitters that are released rapidly and activate closely juxtaposed ligand-gated channels. 

As indicated in the previous sections, whole-cell recordings are widely used to detect neurotransmission in multiple settings however, they possess some shortcomings, which hinder their applicability to all forms of neurotransmission. Whole-cell recordings can only be effective to detect fast neurotransmitters that are released... 

Fig. 4 Stages in synaptic vesicle exocytosis. Putative intermediate steps on the molecular pathway to synaptic vesicle fusion. Vesicle delivery and tethering to the presynaptic membrane most likely involves Rab-proteins and their effectors. So far, the nature of a speculative docking complex (dc) is unclear, but docking appears to be independent from SNARE proteins. In the primed state, SNAREs have assembled into a complex probably stabilized by complexin (Cpx). The fusion reaction is arrested until the intracellular calcium concentration increases. The putative calcium sensor for fast neurotransmitter release, synaptotagmin 1 (Syt), binds to intracellular calcium and in turn triggers fusion by associating with the presynaptic membrane and interacting with the SNARE complex, thereby displacing complexin (Tang et al. 2006).

In the central nervous system both slow and fast changes of potential occur at synapses. The former, quite unknown in the peripheral system, are thought to be effected mainly by polypeptides, some of which are secreted at a synapse (even by a nerve that is also secreting a peripheral-type fast neurotransmitter). 

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