“…Eight groups found evidence consistent with the predictions (McBride et al, 2008, Kleindienst et al, Makino and Malinow, 2011, Chen et al, 2012, Fu et al, 2012, Takahashi et al, 2012, Rah et al, 2013, Druckmann et al, 2014), while two groups did not (Jia et al, 2010, Chen et al, 2011, da Costa and Martin, 2011, Varga et al, 2011). This issue is not resolved and multiple interpretations are still valid (reviewed in DeBello et al, 2014). In experiments where clusters were observed, one consistent finding is inter-synapse distances of ~10 microns or less.…”