Fraction of recycling vesicles that were within the readily releasable pool

Value 32 %
Organism Rat Rattus norvegicus
Reference Waters, J. and Smith, S.J (2002) Vesicle pool partitioning influences presynaptic diversity and weighting in rat hippocampal synapses. J. Physiol., 541(Pt 3):811-23. p.821 left column 2nd paragraphPubMed ID12068042
Primary Source Murthy, V. N. & Stevens, C. F. (1999). Reversal of synaptic vesicle docking at central synapses. Nature Neuroscience 2, 503–507.PubMed ID10448213
Method Abstract:"[Investigators] compared synaptic release and vesicle pool sizes across a large number of hippocampal synapses using FM [fluorescent membrane] 1-43 and confocal fluorescence microscopy. [They] found that the relationship between the number of recycling vesicles at a synapse and its release probability is dependent on firing frequency."
Comments p.821 left column 2nd paragraph:"[Investigators’] hypothesis is that the proportion of recycling vesicles in the readily releasable pool differs from synapse to synapse and that this accounts for the heterogeneity of [their] data. This hypothesis may be consistent with published data if the mean proportion of recycling vesicles in the readily releasable pool is equal to that of these earlier studies. The mean fractional destaining observed in [investigators’] experiments after 60 stimuli at 10 Hz was 31.9 ± 1.1 %. This is remarkably similar to the figure reported by Murthy & Stevens (primary source) who calculated that 32 % of recycling vesicles were within the readily releasable pool. The mean recycling vesicle pool size was also similar at all initial fractional destaining rates at 10 Hz (Fig. 4D), again consistent with the observations of Murthy & Stevens (primary source). In view of the above discussion, it is important to note that [investigators] observed correlations between total recycling pool and readily releasable pool sizes and release probability similar to those reported by previous authors (data not shown)."
Entered by Uri M
ID 112034