Research Technician II Baylor College of Medicine Houston, Texas
Rationale: Attention deficits are common in patients with epilepsy, and a translational electrographic correlate to sustained attention would be helpful to understand the basic mechanisms of these deficits. In human studies, the right posterior parietal cortex (PPC) shows dominance for sustained attention. In addition, phase-amplitude coupling (PAC) throughout the frontoparietal network correlates with performance on attention tasks. However, both hemispheric asymmetries and PAC in rodent PPC during a sustained attention task have not previously been investigated. Methods: Here, we evaluate oscillatory dynamics of bilateral PPC in mice during the 5-Choice Serial Reaction Time Task (5-CSRTT) with progressively increasing task difficulty. A simple task was defined as a stimulus duration of one second with a fixed intertrial interval, and a difficult task was defined as a stimulus duration of 0.6 seconds with a variable intertrial interval. Results: Seven adult mice passed the simple task, and five mice passed the difficult task criteria, with each session including at least 45 correct trials. Right PPC theta-gamma PAC (TG-PAC) and gamma power were independently elevated during the attentive period prior to stimulus presentation and significantly correlated with accuracy in both simple and difficult tasks. Gamma power in the left PPC; however, only correlated with accuracy during a difficult task. Greater task difficulty was also associated with greater hemispheric asymmetry in TG-PAC, favoring the right PPC. Conclusions: These findings highlight the engagement of PPC with sustained attention in mice, reflected by an increase in both TG-PAC and gamma power, with maximal expression in the right hemisphere. Further work is necessary to evaluate the predictive utility of these biomarkers for both normal and aberrant attention processes. Funding: Please list any funding that was received in support of this abstract.: NINDS K08 NS096029; NARSAD Young Investigator Grant
