Naslov
Modulatory role of the prefrontal generator within the auditory M50 network

Autori
Josef Golubić, Sanja ; Aine, Cheryl J. ; Stephen, Julia M. ; Adair, John C. ; Knoefel, Janice E. ; Supek, Selma

Izvornik
Neuroimage (1053-8119) 92 (2014); 120-131

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
M50 cortical sources; prefrontal inhibition; auditory gating; Mild cognitive imparement; Alzheirimer’s disease; Magnetoencephalography

Sažetak
The amplitude variability of P50/M50 components of electromagnetic responses is commonly used to explore the neural ability to modulate its sensitivity to incoming sensory stimuli. Although numerous studies have explored the modulation of the auditory P50/M50 components and suggested multiple generators, there is no agreement on the underlying network or its dynamics. In the present study 275 channel whole-head system MEG measurements and multi-dipole Calibrated Start Spatio Temporal (CSST) localization technique were used to identify the topology and dynamics of the M50 cortical networks during the 30-100 ms post-stimulus interval. Responses were evoked by a passive auditory oddball paradigm in 20 subjects (10 healthy elderly and 10 patients diagnosed with mild cognitive impairment (MCI) or probable Alzheimer disease (AD) ; mean = 74 years). Our spatio-temporal localization yielded four main results: a) three cortical regions underlying M50 generation, bilateral superior temporal gyrus (STG ; 18/20) and prefrontal cortex (PF ; 11/20) ; b) two types of identified M50 network according to subject category, immanent activation of STG accompanied with PF generator in the first (11/20) or lacking PF generator in the second (9/20 ; 9/9 MCI/AD) ; c) PF source dynamic during 30-100 ms time window comprised two peaks, first at 46-50 ms (Mb1) and second 80-88 ms (Mb2) correspondingly to accompanied dynamics of STG generators and d) increased amplitude of M50 peaks in STG responses in the absence of PF generator for both tone condition. Identified M50 networks types enabled differential analysis of PF generator role within M50 network which suggest inhibitory activity of PF generator that suppress or modulated activity of STG generators.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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