Sham training

Fig. 2. T-maze performance (% correct) in gerbils trained on a win-shift strategy to find sunflower seeds (50% is chance level). Gerbils were subjected to sham operation (SHAM) or 5 min of normothermic ischemia with (HYPO) or without delayed hypothermic treatment (ISCH). In (A) the HYPO group was cooled for 1 d at 32°C starting at 1 h after ischemia (26), while in (B) the HYPO gerbils were cooled (32°C + 34°C each for 1 d) starting 6 h after ischemia(2<3). Untreated ischemia resulted in significantly more working memory errors (lower % correct) than SHAM animals, while the HYPO groups were well protected and this generally reflected CA1 cell count data.

Cooper et al. (1993) studied dopamine D-l receptor antagonists in rats with chronic gastric fistula, which were trained to sham-feed a 10 % sucrose solution in a 60 min test. 

Buick et al. (19) used a double-blind experiment in which either packed erythrocytes or saline solutions were infused into highly trained endurance runners. Their results indicated that an increase in hematocrit produces significantly greater work capacity when compared to sham control or pre-infusion values. While these findings have been supported by others (20), Murray et al. (21) cautioned against increasing the hematocrit level above 50% (pcv). At elevated hematocrits, work performance fell as a result of Increased viscosity of the blood. 

While birds could be trained to respond and discriminate among plants, we still had not demonstrated that such behavior was mediated by a nasal chemosensory cue. To answer this question, another series of behavioral experiments was undertaken with birds who had been given either bilateral olfactory nerve cuts or sham surgeries. 

Fig. 4. Percent of animals responding with at least one attack or fight during a 5-min test session. Males in Trained Fighter I and Trained Fighter II are the same those in Trained Fighter III are different. The females in Maternal Aggression III were the aggressive SHAM females from Maternal Aggression I. See text for details.

Points of attention in the DDL test include the possibility to retest a certain test dose, sham treatment to avoid conditioning effects due to the chosen clinical route of the drug candidate versus the common injectable (IP or SC) route of the psychoactive training drugs, and careful consideration of possible responses due to active excipients used as vehicle. Using the clinical route and the feasibility to test different types of formulations in this model adds to the opportunity to use a broad test dose range. 

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