0126 Local Slow Wave Sleep and Post-Stroke Brain Repair

Abstract

Abstract Introduction Recent evidence suggests that slow wave sleep (SWS) is important for synaptic plasticity and brain repair following stroke. Previous studies described a progressive increase in whole cortex and contralesional regional delta power during sleep after stroke, suggesting a global increase in SWS. However, these studies did not distinguish between the effects of global vs. local SWS. We hypothesized that local changes in SWS delta power would parallel changes in the functional remapping and circuit repair. Methods To study SWS in living mice we used Thy-1-GCaMP6f mice (n=12), serially imaged (baseline, 24 hours, weeks 1, 4,) during sleep following photothrombotic stroke of the left forepaw somatosensory cortex (S1FP). An optical fluorescence imaging system (OFI) was used to image whole-cortex neuronal activity. The evolution of local delta activity was compared across three ROIs: 1) infarct, 2) perilesional remapped, and 3) perilesional non-remapped left. Results The photothrombotic infarct encompassed the left S1FP stimulus map, resulting in significant attenuation of S1FP evoked responses at week 1; however, a small region of activation was retained in posterior left S1FP (peri-lesional remapped). The infarct region demonstrated a decrease in delta power during sleep; however, the perilesional region of future remapping exhibited a rebound in focal delta power at 1 week after an initial decline at 24 hours. In the perilesional non-remapped area delta power decreased, but did not increase until week 4. We also observed an early wide-spread increase in delta power at 24 hours and week 1 that decreased on week 4. Conclusion With the high spatial resolution of OFI, we find that SWS is disrupted throughout the brain following focal ischemia. These data suggest that local SWS selectively increases in the region of remapping prior to repair of that circuit and that local SWS may play a role in brain repair following stroke. Support AASM Foundation #183-PA-18, #201-BS-18