Figure 2. Mutation of the rsh gene reveals a major role in aversive olfactory memory (ARM) and is necessary for appetitive olfactory memory shortly after conditioning.

Flies were either trained with odorants paired with electric shock or sugar reward. The training, cold-shock, retention intervals, and testing patterns (both pre and post) are diagrammed for each panel, the time axis is not to scale. (A) Olfactory memory tested three min after training is reduced in rsh¹ flies compared to CS flies, although levels do not reach statistical significance (F(1,12)  = 3.5, P = 0.09). To reveal the rsh function in aversive olfactory memory, wild-type CS and rsh¹ flies were trained with odorant / shock pairings, then after 2 hrs were given a cold-shock, memory was tested 1 hr later. Memory performance of rsh¹ flies was significantly lower than wild-type CS flies with this procedure (F(1,10)  = 5.0, *  =  P = 0.04). (B) Appetitive olfactory short-term memory was tested at 3, 30, and 60 min after the odorant / sucrose training session. A rsh¹ phenotype was evident at all tested time points after training (3 min: F(1,16)  = 29.2, ***  =  P<0.001; 30 min: F(1,14)  = 12.3, **  =  P<0.01; 60 min: F(1,14)  = 12.1, **  =  P<0.01). (C) The rsh¹ appetitive short term olfactory memory phenotype is rescued with a transgenic copy of the wild-type version of the rsh gene (F(3,32)  = 13.0, P<0.0001; post-hoc tests: CS vs rsh¹ ***  = P<0.001, rsh¹ vs. rsh¹; hs-rsh-1 *  = P<0.05, CS vs. rsh¹; hs-rsh-1, *  = P<0.05; rsh¹ vs. CS; hs-rsh-1 *  = P<0.05; CS vs. CS; hs-rsh-1 *  = P<0.05). The values are means and error bars represent s.e.m.