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NMDA receptor antagonist high-frequency oscillations are transmitted via bottom-up feedforward processing
Jacek Wróbel1, Władysław Średniawa1, Aleksandra Bramorska1
1Laboratory of Neuroinformatics, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Street, 02-093, Warsaw, Poland.
Scientific Reports
|September 19, 2024
Summary
NMDA receptor antagonist-induced high-frequency oscillations (HFO) in the piriform cortex are driven by the olfactory bulb. This suggests bottom-up mechanisms mediate HFO transmission in olfactory circuits.
Area of Science:
- Neuroscience
- Computational Neuroscience
- Systems Neuroscience
Background:
- NMDA receptor antagonists induce high-frequency oscillations (HFO) in mammalian brain regions.
- The transmission mechanisms (feedforward vs. feedback) of these HFO remain unclear.
- The olfactory bulb (OB) is a key node in NMDA receptor-dependent HFO networks.
Purpose of the Study:
- Investigate the transmission modality of NMDA receptor antagonist-induced HFO in the olfactory system.
- Determine whether the olfactory bulb (OB) or piriform cortex (PC) drives HFO.
- Clarify the role of bottom-up versus top-down mechanisms in HFO propagation.
Main Methods:
- Electrophysiological recordings using silicon probes in the piriform cortex (PC).
- Analysis of Granger causality and peak-lag to determine oscillation drivers.
- Reversible inhibition of the olfactory bulb (OB) and piriform cortex (PC) to assess functional connectivity.
Main Results:
- NMDA receptor antagonist-induced HFO were detected in the PC, with lower power than in the OB.
- Granger causality and peak-lag analyses identified the OB as the primary driver of PC oscillations.
- Inhibition of the OB significantly reduced HFO power in both OB and PC, while PC inhibition had minimal effect on OB activity.
Conclusions:
- Findings indicate that bottom-up mechanisms, originating from the OB, mediate the transmission of NMDA receptor antagonist-induced HFO.
- The olfactory bulb acts as the driver, and the piriform cortex as a recipient, in this specific HFO network.
- This study elucidates the directional flow of information in NMDA receptor-dependent oscillatory activity within olfactory circuits.
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