Anomalous decay of power in high frequency oscillations (HFO) with distance from the source

• Autorzy: Gorski T. , Hunt M. , Kasicki S. , Wojcik D.
• Języki publikacji: EN

Abstrakty

EN

BACKGROUND AND AIMS: Brain electric potentials recorded extracellularly are generated by transmembrane currents leaving and entering active neurons. Electric charge conservation requires that these currents are balanced in every cell separately, which implies a dipolar structure of sources. We previously reported results suggesting a monopolar structure of high-frequency oscillations (135–165 Hz) generated in nucleus accumbens (NAc) which seems to be inconsistent with known physics. The goal of this study is to find out through numerical simulations if the specific morphology and spatial distribution of accumbal neurons can shed light on this paradox. METHODS: Multi-compartment models of medium spiny neuron (MSN) from NAc (based on ModelDB, accession nr 112834) were used for simulations in the NEURON simulator. We computed transmembrane activity of a population of MSNs in response to different oscillating stimuli. The sum of extracellular potentials generated by individual cells in selected points in space simulated the local field potential. Potentials were filtered in different bands to study the decay of the power with distance from the source. RESULTS: We show that the observed increased power in the HFO band can be explained by coherent spiking of population of MSNs. In all the studied frequency bands and in all directions we observe asymptotic decay with distance close to what is expected from dipolar sources (1/r^2). However, over short spatial scales, the scaling does get closer to monopolar decay (1/r). These results are compared with reevaluated decay data from Hunt et al. (2010). CONCLUSIONS: Since the numerical results are consistent with the experimental results it seems that the specific morphology and distribution of MSNs within NAc are sufficient to explain the observed anomalous decay of HFO power over intermediate distances. There is no need for consideration of additional mechanisms, for example, capacitive effects of the extracellular space.

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2015
• Tom: 75
• Numer: Supl.
• Opis fizyczny: p.S104

Twórcy

autor

Gorski T.

• Nencki Institute of Experimental Biology, Polish Academy of Science, Warsaw, Poland

autor

Hunt M.

• Nencki Institute of Experimental Biology, Polish Academy of Science, Warsaw, Poland

autor

Kasicki S.

• Nencki Institute of Experimental Biology, Polish Academy of Science, Warsaw, Poland

autor

Wojcik D.

• Nencki Institute of Experimental Biology, Polish Academy of Science, Warsaw, Poland