Related Experiment Video
Updated: May 22, 2026
Assessment of Sexual Behavior of Male Mice
Published on: March 5, 2020
Differential effects of modafinil, methamphetamine, and MDMA on agonistic behavior in male mice
Alena Machalova1, Karel Slais, Dagmar Vrskova
1CEITEC-Central European Institute of Technology, Masaryk University, Brno, Czech Republic.
Abstract:
The aim of the present study was to compare the behavioral effects of modafinil, an atypical psychostimulatory acting and cognitive-function improving drug, with the effects of the psychostimulants methamphetamine (MET) and MDMA (3,4-methylenedioxymethamphetamine, or "ecstasy") in a model of mouse agonistic behavior. This model enables the observation of ethologically well-defined sociable, timid, aggressive, and locomotor behavioral acts and postures. Singly-housed male mice (isolates) were separated into 4 groups. The observations were performed in 4 sessions, 1 week apart. In each interaction, singly-housed mice were paired with non-aggressive group-housed partners for 4 min in a neutral environment. The isolates received, in a Latin square design, either a) a vehicle or modafinil at doses 2.0, 10.0, or 50.0 mg/kg; or b) a vehicle or MET at doses 1.0, 5.0, or 10.0 mg/kg; or c) a vehicle or MDMA at doses 2.5, 10.0, or 30.0 mg/kg. The isolates were categorized as timid or aggressive according to their behavior in the control interaction (vehicle pre-treatment). Elements of locomotor, sociable, aggressive, and timid behavior were evaluated (one-way ANOVA). In the aggressive mice, no change in the sum of aggressive behavior was measured following modafinil administration, while both methamphetamine and MDMA produced dose-dependent inhibition of aggression (p<0.01). The substantial difference in the tested drug effects on agonistic behavior was an increased occurrence of sociable acts (p<0.01) accompanied by a simultaneous increase of timid acts (p<0.01) recorded after MDMA, but not after modafinil or methamphetamine administration. In the timid mice, at least some doses of modafinil decreased timidity (p<0.01) and increased aggression (p<0.01) with no effect on sociability. Administration of MDMA increased timid activities (p<0.01). Both MDMA and MET decreased sociability (p<0.01).
Insights
Modafinil did not alter aggression in mice, unlike methamphetamine and MDMA which reduced it. MDMA uniquely increased sociability and timidity, while modafinil decreased timidity in aggressive mice.
Area of Science:
- Neuroscience
- Behavioral Pharmacology
- Psychopharmacology
Background:
- Modafinil is an atypical psychostimulant with cognitive-enhancing properties.
- Methamphetamine (MET) and MDMA (3,4-methylenedioxymethamphetamine) are known psychostimulants with distinct behavioral effects.
- Understanding the comparative behavioral pharmacology of these agents is crucial for their therapeutic and recreational use contexts.
Purpose of the Study:
- To compare the behavioral effects of modafinil, methamphetamine (MET), and MDMA in a mouse model of agonistic behavior.
- To investigate the impact of these drugs on aggressive, timid, sociable, and locomotor behaviors.
- To differentiate the ethological profiles of modafinil, MET, and MDMA in social interactions.
Main Methods:
- A mouse model of agonistic behavior was employed, observing interactions between singly-housed isolates and group-housed partners.
- Mice received vehicle, modafinil (2.0-50.0 mg/kg), MET (1.0-10.0 mg/kg), or MDMA (2.5-30.0 mg/0.0 kg) in a Latin square design.
- Behavioral acts including locomotor, sociable, aggressive, and timid behaviors were quantified and analyzed using one-way ANOVA.
Main Results:
- Modafinil did not alter aggression in aggressive mice, whereas MET and MDMA dose-dependently inhibited aggression.
- MDMA uniquely increased both sociable and timid behaviors in aggressive mice, an effect not observed with modafinil or MET.
- In timid mice, modafinil decreased timidity and increased aggression, while MDMA increased timid activities and both MDMA and MET decreased sociability.
Conclusions:
- Modafinil, MET, and MDMA exhibit distinct behavioral profiles in agonistic interactions.
- MDMA's effects are unique, promoting sociability alongside timidity, contrasting with MET's aggression inhibition and modafinil's effects on timidity and aggression.
- These findings highlight differential psychopharmacological actions relevant to understanding drug-induced behavioral changes.
