The nature of hemispheric specialization of brain activity during rhythm processing remains poorly understood. The locus for rhythmic processing has been difficult to identify and there have been several contradictory findings. We therefore used functional magnetic resonance imaging to study passive rhythm perception to investigate the hypotheses that rhythm processing results in left hemispheric lateralization of brain activity and is affected by musical training. Twelve musicians and 12 nonmusicians listened to regular and random rhythmic patterns. Conjunction analysis revealed a shared network of neural structures (bilateral superior temporal areas, left inferior parietal lobule, and right frontal operculum) responsible for rhythm perception independent of musical background. In contrast, random-effects analysis showed greater left lateralization of brain activity in musicians compared to nonmusicians during regular rhythm perception, particularly within the perisylvian cortices (left frontal operculum, superior temporal gyrus, inferior parietal lobule). These results suggest that musical training leads to the employment of left-sided perisylvian brain areas, typically active during language comprehension, during passive rhythm perception.

Accessibility control of V(D)J recombination at Ag receptor loci depends on the coordinate activities of transcriptional enhancers and germline promoters. Recombination of murine Tcrd gene segments is known to be regulated, at least in part, by the Tcrd enhancer (Eδ) situated in the Jδ2-Cδ intron. However, there has been little characterization of promoters and other cis-acting elements that are activated by or collaborate with Eδ and that might function to regulate Tcrd gene recombination events. We now describe a strong promoter that is tightly associated with the murine Dδ2 gene segment. EMSAs reveal that upstream stimulatory factor 1, Runx1, c-Myb, lymphoid enhancer binding factor 1, NF1, and E47 all interact with this promoter in vitro. Of these, upstream stimulatory factor 1, Runx1, and c-Myb appear necessary for full promoter activity in transiently transfected cells. Moreover, the same three factors were found to interact with the promoter in vivo by chromatin immunoprecipitation. We suggest that these factors play important roles as Eδ-dependent regulators of Dδ2 accessibility in vivo. Consistent with the established roles of c-Myb and Runx factors in Eδ function, we detected low level, enhancer-independent activity of the Dδ2 promoter in transient transfection experiments. We speculate that the Dδ2 promoter may play a role as a weak, enhancer-independent regulator in vivo, and might contribute to residual Tcrd rearrangement in Eδ−/− mice.

EGG, abdominal NIRS, and AC, whenever used simultaneously, can provide objective and synergistic measures that correlate with PMA. These findings may be helpful in the assessment of feeding readiness because they reveal quantitative measures suggestive of the developmental process of the gut.