Utility of an elevated plus-maze for the evaluation of memory in mice: effects of nootropics, scopolamine and electroconvulsive shock

Abstract

An elevated plus-maze consisting of two open and two enclosed arms was employed for an evaluation of memory in mice. Mice in the plus-maze escaped from the open arm to the enclosed arm because mice apparently dislike open and high spaces. The time it took for the mice to move from the open arm to the enclosed arm (transfer latency) was recorded. The transfer latency after the 2nd day was significantly shorter than that on the 1st day when it was recorded at a rate of one trial a day for 5 days. The transfer latency on the 2nd day was significantly prolonged in the mice administered electroconvulsive shock (300 V, 1 s) or scopolamine (20 micrograms, ICV) immediately after the first trial compared to the transfer latency in the control group. The prolongation of transfer latency in the mice administered an electroconvulsive shock was reversed by pretreatment with aniracetam (20 mg/kg, PO), but not tacrine and physostigmine. The prolongation of transfer latency in the mice administered scopolamine was reversed by pretreatment with aniracetam (10 and 20 mg/kg, PO) tacrine (1 and 3 mg/kg, PO), or physostigmine (0.025-0.2 mg/kg, IP). These results suggest that transfer latency may be one of the parameters of learning and memory.

Involvement of the Sigma1 Receptor in Cocaine-induced Conditioned Place Preference Possible Dependence on Dopamine Uptake Blockade

“…The elevated plus-maze was used to evaluate spatial long-term memory, involving the previously described procedure (Itoh et al 1990(Itoh et al , 1991Maurice et al 1994). The apparatus consisted of two open arms (23.5 ϫ 8 cm), painted white, and two enclosed arms (23.5 ϫ 8 ϫ 20 cm high), painted black.…”

“…The elevated plus-maze involving a protocol allowing a reliable measure of memory was used, with the benefit that similar instinctive cues as place preference conditioning were involved (Itoh et al 1990(Itoh et al , 1991. On day 1, animals were trained to learn the maze.…”

“…On day 2, a significant decrease of the transfer latency was measured, 17 Ϯ 1 s (p Ͻ .01, Wilcoxon's paired non-parametric test). This 27 s decrease is regarded as an index of long-term memory (Itoh et al 1990(Itoh et al , 1991Maurice et al 1994). None of the drug treatment significantly affected the transfer latency during the first session: KW ϭ 1.07, p Ͼ .05 for cocaine ( …”

Morphine Tolerance and Reward but not Expression of Morphine Dependence are Inhibited by the Selective Glutamate Carboxypeptidase II (GCP II, NAALADase) Inhibitor, 2-PMPA

“…To assess the effects of 2-PMPA on acquisition and/or retrieval of memory, we used the elevated plus maze model of spatial learning in mice (Itoh et al, 1991). This paradigm is sensitive to the amnesic effects of post-training administration of scopolamine or electroconvulsive shock (Itoh et al, 1990), pretraining effects of scopolamine, MK-801 and diazepam (Itoh et al, 1991), and pretest effects of MK-801 and scopolamine (Hlinak and Krejci, 2000). Results of Experiment 5 demonstrating amnesic effects of MK-801 confirm earlier observations (Itoh et al, 1991); however, we found that in contrast to MK-801, 2-PMPA (50 and 100 mg/kg) affected neither learning nor retrieval of memory.…”

Effect of Resveratrol as Caloric Restriction Mimetic and Environmental Enrichment on Neurobehavioural Responses in Young Healthy Mice

“…The elevated plus maze was used to evaluate short-term spatial memory [36]. Briefly, the elevated plus maze for mice consists of two perpendicular open arms (21.5 × 7.5 cm) and two closed arms (21.5 × 7.5 × 20 cm) which extends from a central 7.5 × 7.5 cm platform.…”