A mutation in <i>dSK</i> results in increased acquisition of short-term memory 30 min after 1.5 h ‘short’ training session.

<p>Short-term memory (STM) paradigm. During training period (1.5 h), male flies are individually placed in small chambers with (trained) or without (naïve) mated females in small (B) or large (C) training chambers. After a 30 min rest period in isolation, each male was tested by pairing with a mated female for 10 min. (A) Courtship indices of naïve and trained males for each group were measured during testing with mated females 30 min after STM training (A) in small chambers. Note the significant suppression in courtship levels of trained males relative to that of the naïve flies within each group. Mean+SEM is shown. (**P<0.01, t test). (B) Same as in (B) except that training is limited by increasing chamber size as shown. Only trained <i>dSK⁻</i> flies exhibit robust courtship suppression. Mean+SEM is shown. (*P<0.05, t test).</p

Effects of dSK inactivation on 24 h courtship memory formation.

<p>Courtship indices of naïve and trained males for each group were measured during testing with mated females 24 h after LTM training. Note that only flies expressing dSKDN in 201y-positive neurons do not show training-induced courtship suppression and therefore are severely impaired in 24 h courtship memory. Mean+SEM is shown. (*P<0.05, t test).</p

dSK expression in larval and adult brains.

<p>(A) A single confocal section through a WT larval brain stained with dSK antibody (green) and pre-synaptic marker nc82 (blue). dSK is highly expressed in PNs connecting ALs and MB calyx. (B) A confocal section through a <i>GH146-GAL4/+;UAS-mCD8GFP/+</i> stained with anti-dSK antibody (red). Notice dSK expression in PNs both in ALs and MB calyx.</p

Effects of dSK inactivation on 30 min courtship memory acquisition.

<p>(A) Courtship indices of naïve and trained males for each group were measured during testing with mated females 30 min after STM training in large chambers. Mean+SEM is shown. (*P<0.05, **P<0.01, t test). (B) Learning indices (LIs) were calculated from courtship indices of naïve and trained males within each group as described before <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0034665#pone.0034665-Keleman1" target="_blank">[22]</a> (also see text). Note the significant 30 min memory enhancement when dSKDN is expressed either sets of neurons. Mean LI is shown. *P<0.05 for H₀: LI = LI_201y-GAL4, **P<0.01 for H₀: LI = LI_GH146-GAL4.</p