Findings from the present study showed that baseline ERO energy in the frontal alpha/beta band and in the parietal delta, theta and alpha/beta bands were significantly reduced in B6 mice, compared to D2 mice. Studies have shown behavioral differences between B6 and D2 mice (Crawley et al., 1997; Mayeda and Hofstetter, 1999). Findings from these studies indicated that B6 mice showed higher levels of motor activity and better performance in the Morris water maze and contextual fear conditioning tasks than D2 mice. In contrast, while B6 mice showed greater baseline startle responses than D2 mice, they showed reduced levels of anxiety-like behaviors and prepulse inhibition (PPI) than D2 mice (Crawley et al., 1997; DuBois et al., 2006). Whether the neural mechanisms mediating behavioral differences between B6 and D2 mice play a role in the strain-dependent differences in cortical ERO energy remain unclear. While ERO and PLI analyses were performed with baseline-corrected values, future studies are needed to determine whether strain-dependent behavioral activity and basal levels of ERO activity and phase locking play a role in the different neurophysiological profile found between B6 and D2 mice.
