Research Highlight:High-frequency oscillations in human and monkey neocortex during the wake-sleep cycle

Alain Destexhe ENP team, including ENP GP Alumni N. Dehghani and L. Muller, evaluated beta-/gamma-fast-oscillations during the wake-sleep cycle at the level of the local circuitry (high-density intracanial recordings from a large number of cells) identifying regular-spiking RS neurons (putative excitatory pyramidal) from fast-spiking FS cells (putative inhibitory interneurons). Both in human and monkey, the fast-oscillations are characterized by a strong implication of FS cells. Moreover, they observed that coherent waves of fast-oscillations are travelling over several millimeters in the human/monkey neocortex only during sleep resulting in the generation of spatio-temporal patterns and large-scale oscillation coherence in the sleeping brain (inhibition-driven beta- and gamma-oscillations). Interestingly,  they observed the highest coherence during the slow-wave sleep. This increased coherence could perhaps play a role in memory consolidation by inducing long-term changes in cortical circuits. 

Check out the article: 

Le Van Quyen, M., Muller, L., Telenczuk, B., Cash, S.S., Halgren, E., Hatsopoulos, N.G., Dehghani, N. and Destexhe, A.  High-frequency oscillations in human and monkey neocortex during the wake-sleep cycle.
Proc. Natl. Acad. Sci. USA 113: 9363-9368, 2016.
DOI: 10.1073/pnas.1523583113


Figure 1.:  γ- and β-Oscillations during sleep and wakefulness. (A) γ- and β-oscillations were identified in LFPs during SWS and wakefulness (Wake) in both human and monkey. The raw and filtered traces (Top) and wavelet time frequency of the sample epoch (Bottom) are shown. Chan, channel. (B) These oscillations most frequently appeared at about the same time across the array, forming broad spatial patterns. Red and blue dots are spiking from inhibitory FS and excitatory RS cells recorded with the same electrodes from which the LFP oscillatory envelope is calculated.