Cortical slow oscillations (0.1 - 1 Hz), which may play a role in memory consolidation, are a hallmark of non-rapid eye movement (NREM) sleep and also occur under anaesthesia. During slow oscillations the neuronal network generates faster oscillations on the active Up-states and these nested oscillations are particularly prominent in the PFC. In rodents the mPFC consists of several subregions: anterior cingulate cortex (ACC), prelimbic (PrL), infralimbic (IL) and dorsal peduncular cortices (DP). Although each region has a distinct anatomy and function, it is not known whether slow or fast network oscillations differ between subregions in vivo. We have simultaneously recorded slow and fast network oscillations in all four subregions of the rodent mPFC under urethane anaesthesia. Slow oscillations were synchronous between the mPFC subregions, and across the hemispsheres, with no consistent amplitude difference between subregions. Delta (2-4 Hz) activity showed only small differences between subregions. However, oscillations in the spindle (6-15 Hz), beta (20-30 Hz), gamma (30-80 Hz) and high gamma (80-150 Hz) frequency bands were consistently larger in the dorsal regions (ACC and PrL) compared to ventral regions (IL and DP). In dorsal regions the peak power of spindle, beta and gamma activity occurred early after onset of the Up-state. In the ventral regions, especially DP, the oscillatory power in the spindle, beta and gamma frequency ranges peaked later in the Up-state. These results suggest variations in fast network oscillations within the mPFC that may reflect the different functions and connectivity of these subregions.
- Prefrontal cortex
- slow oscillations
- Copyright © 2016, Journal of Neurophysiology