Blockade of biVPN (by expressing the temperature sensitive shits.UAS.cUa under the control of Scer\GAL4GMR53A05 and shifted to the permissive 33[o]C) decreases olfactory medium term memory (1h) if experiment is carried out in crowded conditions (groups of 32 flies - socially facilitated memory) but not in non-crowded conditions (groups of 4 flies).