1 research outputs found
Variable delay-to-signal: a fast paradigm for assessment of aspects of impulsivity in rats
Testing impulsive behavior in rodents is challenging and labor-intensive. We developed a new behavioral paradigm-the Variable Delay-to-Signal (VDS) test-that provides rapid and simultaneous assessment of response and decision impulsivity in rodents. Presentation of a light at variable delays signals the permission for action (nose poke) contingent with a reward. 2 blocks of 25 trials at 3 s delay flank a block of 70 trials in which light is presented with randomly selected 6 or 12 s delays. Exposure to such large delays boosts the rate of premature responses when the delay drops to 3 s in the final block, an effect that is blunted by an acute methamphetamine challenge and that correlates with the delay-discounting (DD) paradigm (choice impulsivity). Finally, as expected, treatment with the NMDA antagonist MK-801 caused a generalized response increase in all VDS blocks. The pharmacological validation, particularly with methamphetamine which has a well established dual effect on response and decision impulsivity, and the correlations between the impulsive behavior in the DD and VDS paradigms, suggests that the later is able to provide, in a single session, a multi-dimensional assessment of impulsive behavior.The work wa ssupported by a fellowship âSFRH/BPD/80118/2011â funded by FCTâPortuguese Foundation for Science and Technology and by FEDER funds through Operational program for competitivity factorsâCOMPETE and by national funds through FCTâFoundation for Science and Technology to projects PTDC/SAU-NEU/108557/2008 and PTDC/SAUNSC/111814/2009