The real-time behavioral effect of spontaneous brain activity

Hochschulschrift

Abstract: The brain is constantly active. The environment requires us to adapt our behavior in response to external cues. Therefore, the interaction between spontaneous and externally evoked neuronal activity is key for understanding cognition. Imaging studies describe functionally connected networks termed resting state networks (RSNs), which are activated spontaneously and during tasks. RSNs were suggested to oppose each other and thus play a role in the interaction between internal and external cues, but this suggestion is under debate. Recent evidence indicates that spontaneously occurring bursts of high-power local field potential (LFP) oscillations in the 15-30 Hz beta-band represent activation of RSNs. LFP-bursts can be detected in fine timescales, thus allow investigating their impact on behavior on the single-trial level. The behavioral impact of intrinsic LFP-bursts was demonstrated on a variety of behaviors, from perception, through working memory and attention, to movement in health and disease. A repeating effect of beta-bursts in the literature is inhibitory, manifested as a masking-effect on perception or maintaining the status-quo in movement. Spontaneously occurring beta oscillations, representing network input, is anti-correlated with the stimulus-evoked spiking output. This may indicate an ongoing local competition between inputs and outputs, or spontaneous and evoked activities. Yet, a demonstration of the effect of beta-bursts in real-time is missing, and little is known about the underlying mechanism.
In this work, we propose that oscillatory bursts may constitute the mesoscopic link between macroscopic functional networks and microscopic assemblies of spiking neurons. Packets of spikes from a sender within one RSN are translated via cellular and network mechanisms into LFP-bursts by the receiver in another RSN. The anti-correlation between spiking activity and beta-power within a region on one hand, and between RSNs on the other, may represent the competition between functional networks. Based on this synthesis, we hypothesized that high levels of spontaneous activity, manifested as beta-bursts, could influence behavior in real-time.
To test this hypothesis, we developed a method to measure short and narrowband LFP-bursts in real-time. In a first study, we demonstrated the capability of the method to detect behaviorally relevant bursts; we trained freely moving rats to increase the occurrence of bursts and were able to decode the occurrence of bursts from movement. Then, we combined the real-time method with a novel forepaw detection task including a tactile vibrational stimulus and multi-electrode recordings, to investigate the real-time masking effect of beta-bursts on sensory inputs and the relationship between neuronal populations and bursts. We found that by bidirectional adjustment of the stimulus intensity according to real-time detected bursting levels, the masking effect of beta-bursts can be counterbalanced. Further, we found that bursts in a wide range of frequencies were associated with transient synchronization of cell assemblies. Only in the beta band, bursts were anti-correlated with stimulus-evoked activity and were followed by a reduction of firing-rate. Our studies suggest that spontaneous beta-bursts reflect a dynamic state that competes with external stimuli

Object Details

• Location: Deutsche Nationalbibliothek Frankfurt am Main
• Extent: Online-Ressource
• Language: Englisch
• Notes: Universität Freiburg, Dissertation, 2021

Classification and Topics

• Keyword: Hirnfunktion ; Gehirn ; Nervennetz ; Magnetoencephalographie ; Rat

Contributors, Places and Time

• Event: Veröffentlichung
• (where): Freiburg
• (who): Universität
• (when): 2023
• Creator: Karvat, Golan
• Contributor: Diester, Ilka ; Rotter, Stefan ; Mehring, Carsten ; Albert-Ludwigs-Universität Freiburg. Optophysiologie ; Albert-Ludwigs-Universität Freiburg. Fakultät für Biologie ; Albert-Ludwigs-Universität Freiburg. Fakultät für Biologie

Further information

• DOI: 10.6094/UNIFR/232424
• URN: urn:nbn:de:bsz:25-freidok-2324243
• Rights: Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Last update: 25.03.2025, 1:47 PM CET