RT Journal Article
SR Electronic
T1 A supragranular nexus for the effects of neocortical beta events on human tactile perception
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 750992
DO 10.1101/750992
A1 Robert G. Law
A1 Sarah Pugliese
A1 Hyeyoung Shin
A1 Danielle Sliva
A1 Shane Lee
A1 Samuel Neymotin
A1 Christopher Moore
A1 Stephanie R. Jones
YR 2019
UL http://biorxiv.org/content/early/2019/09/02/750992.abstract
AB Transient neocortical events with high spectral power in the 15–29Hz beta band are among the most reliable predictors of sensory perception: High prestimulus beta event rates in primary somatosensory lead to sensory suppression, most effective at 100–300ms prestimulus latency. However, the synaptic and neuronal mechanisms inducing beta’s perceptual effects have not been completely localized. We combined human MEG with neural modeling designed to account for these macroscale signals to interpret the cellular and circuit mechanisms that underlie the influence of beta on tactile detection. Extending prior studies, we modeled the hypothesis that higher-order thalamic bursts, sufficient for beta event generation in cortex, recruit supragranular GABAB inhibition acting on a 300ms time scale to suppress sensory information. Consistency between model and MEG data supported this hypothesis and led to a further prediction, validated in our data, that stimuli are perceived when beta events occur simultaneously with tactile stimulation. The post-event suppressive mechanism explains an array of studies that associate beta with decreased processing, while the during-event mechanism may demand a reinterpretation of the role of beta events in the context of coincident timing.Significance statement Somatosensory beta events – transient 15-29Hz oscillations in electromagnetic recordings – are thought to be generated when “top-down” bursts of spikes presumably originating in higher-order thalamus arrive in upper layers of somatosensory cortex. Physiological evidence had shown that the immediate action of these top-down projections should be excitatory; however, after a beta event, sensory perception is noticeably inhibited for approximately 300ms. The source of this post-event sensory suppression, in particular, had been unresolved. Using a detailed computational model of somatosensory cortex, we find evidence for the hypothesis that these bursts couple indirectly to GABAB inhibition in upper layers of cortex, and that beta events first briefly disinhibit sensory relay before a longer period of inhibition.