Repeated Acquisition in the Morris Swim Task: Effects of Methylenedioxymethamphetamine, Methamphetamine, and Methylphenidate

Abstract

Acute effects of methylenedioxymethamphetamine (MDMA), methamphetamine (MA) and methylphenidate (MPD) were studied using a within-subject, repeated acquisition/performance procedure adapted to the Morris Swim Task. To investigate place learning, the acquisition component consisted of a hidden platform that varied in location across experimental sessions. As a control for drug effects not specific to acquisition, a performance component was included in which the hidden platform was in the same pool location in every experimental session. All three drugs increased escape latencies and swim distances in dose-dependent fashion. However, impairment in the acquisition component was generally observed only at doses that also produced impairment in the performance component, suggesting that effects were not selective to place learning. None of the drugs produced enhancement of learning or performance at any dose. Taken together, the results suggest that acute exposure to these psychomotor stimulants produce global impairment of performance in the Morris task, rather than specific deficits in place learning.

Effects of MDMA on olfactory memory and reversal learning in rats

“…For example, Harper et al (2005) showed that MDMA effects on delayed matching-to-sample were independent of delay, that is, comparable levels of disruption were observed under conditions of no delay (which presumably do not involve working memory), as well as with delays. Similarly, Galizio et al (2014) found that MDMA increased latency to locate the hidden platform in the Morris Swim Task, but only at doses that also impaired overall perceptual-motor ability. Finally, Kay, Harper and Hunt (2010) found that acute doses of MDMA impaired performance on a reference memory version of the radial arm maze at doses that had no effect on the working memory version of the task.…”

“…However, in larger, open designs, such as the Morris Swim Task (Galizio et al, in press), it has been reported that acute MDMA impairs performance by interfering with the learned response itself. Galizio et al (2014) reported that high doses of MDMA altered the path taken to approach a hidden platform in the water maze and frequently resulted in response failures. The authors suggested that this effect could be due to behavioral alterations which are incompatible with efficient navigation of the maze, such as thigmotaxis or motor deficits.…”

“…Numerous studies have shown that acute MDMA administration can impair performance on learning and working memory tasks in rodents (e.g., Arias-Cavieres et al, 2010; Braida, Pozzi, Cavallini & Sala, 2002; Byrne, Baker & Poling, 2000; Galizio, McKinney, Cerutti & Pitts, 2009; Galizio et al, 2014; Harper, Wisnewski, Hunt & Schenk, 2005; Marston, Reid, Lawrence, Olverman & Butcher, 1999). However, whether these disruptions are specific to working memory processes is not clear.…”

Cognitive Effects of MDMA in Laboratory Animals: A Systematic Review Focusing on Dose

“…These results suggest that pretreatment with repeated doses of 10 mg/kg MDMA has no subsequent effect on spatial working memory. Galizio et al (2014) performed a repeated acquisition/performance procedure on the MWM. The acquisition component assessed working memory, as the platform location changed each day, while the performance component (see section V.C.1.a) assessed reference memory, as the platform location remained fixed over all days.…”

“…In Wistar rats, doses of 1.25-5 mg/kg had no effects (Young et al, 2005) and doses of 5-15 produced impairments (Taghizadeh et al, 2016). In Sprague-Dawley rats, doses of 0.3-1.7 mg/kg had no effects (Kay et al, 2010;Galizio et al, 2014) and doses of 3-5.6 mg/kg produced impairments (Kay et al, 2010(Kay et al, , 2011Harper et al, 2013;Galizio et al, 2014). The postdrug findings remain mixed, as there is evidence that highly similar/identical experimental designs produced dissimilar effects.…”