MRI provides a handful of qualitative and quantitative structural measures. The most commonly used is T1-weighted imaging, which provides the best contrast for studies of gross anatomy (macrostructure). Recent studies have addressed the relationship between tissue microstructure and Entinostat supplier cognitive performance using diffusion MRI (Klingberg et al., 2000, Moseley et al., 2002 and Sasson et al., 2010), a technique considered to be a microstructural probe. Diffusion tensor imaging (DTI), a framework of diffusion MRI,

provides a multitude of quantitative indices that reflect the micron-scale density and organization of the tissue (Assaf and Pasternak, 2008 and Basser, 1995). Indices derived from DTI include the mean diffusivity (MD) and fractional anisotropy (FA), which serve respectively as measures of tissue density and fiber organization/directionality CHIR-99021 in vitro (Pierpaoli and Basser, 1996). In this study, we used DTI to detect structural changes in brain tissues of individuals after they had performed a spatial learning and memory task based on a computer car race game (Electronic Arts). A cohort of 46 volunteers was divided into

a learning group and 2 control groups. The learning group (n = 17) repeated a single track 16 times, divided into 4 sessions of 4 trials each. Their objective was to learn the track and achieve better lap times. To enhance memorization, at the end of each session, subjects were given snapshots of

locations in the track, which they had to arrange in the isothipendyl correct order. In addition they were asked to sketch an outline of the track at the end of each session. Subjects were engaged in the overall task for 90 min on average. Each subject underwent a DTI scan before and immediately after the task (i.e., the interval between the two scans was approximately 2 hr). Because the task included procedural learning (control of the car) as well as spatial learning and memorization, a group of 15 subjects was used to control for this aspect. These subjects played the car game for the same duration as the learning group, but the track was different in each trial. Therefore, compared to the learning group, the memorization of a single track was limited, and spatial learning was apparently attenuated. The second control group (n = 14) did not perform any task, and waited between scans for the equivalent duration of the car racing tasks. All subjects in the learning group showed improvement in the task. Their lap times decreased significantly (Figure 1; decrease in normalized lap time [mean ± SEM] was 20% ± 0.4%, p < 0.0001; for absolute values see Figure S1A available online), and their arrangement of snapshots improved (p < 0.0001; Figure S1). The active control group showed no improvement in their normalized lap time (Figure 1).