Adaptation Modulates Spike-Phase Coupling Tuning Curve in the Rat Primary Auditory Cortex.

Mohammad Zarei,Mehran Jahed,Mohammad Reza Daliri,Mohsen Parto Dezfouli

doi:10.3389/fnsys.2020.00055

Abstract

Adaptation is an important mechanism that causes a decrease in the neural response both in terms of local field potentials (LFP) and spiking activity. We previously showed this reduction effect in the tuning curve of the primary auditory cortex. Moreover, we revealed that a repeated stimulus reduces the neural response in terms of spike-phase coupling (SPC). In the current study, we examined the effect of adaptation on the SPC tuning curve. To this end, employing the phase-locking value (PLV) method, we estimated the spike-LFP coupling. The data was obtained by a simultaneous recording from four single-electrodes in the primary auditory cortex of 15 rats. We first investigated whether the neural system may use spike-LFP phase coupling in the primary auditory cortex to encode sensory information. Secondly, we investigated the effect of adaptation on this potential SPC tuning. Our data showed that the coupling between spikes’ times and the LFP phase in beta oscillations represents sensory information (different stimulus frequencies), with an inverted bell-shaped tuning curve. Furthermore, we showed that adaptation to a specific frequency modulates SPC tuning curve of the adapter and its neighboring frequencies. These findings could be useful for interpretation of feature representation in terms of SPC and the underlying neural mechanism of adaptation.

Highlights

We investigated sensory information coding in terms of spike-phase coupling (SPC) tuning curve and explored how adaptation could alter this potential SPC-based tuning curve
Stimulus-specific adaptation understood as an interesting phenomenon in the neural system, including the auditory cortical neurons, (Ulanovsky et al, 2003, 2004; Ayala and Malmierca, 2012), here on denoted to as “Adaptation.” stimulus-specific adaptation (SSA) affects a major decrease in neural responses to frequent stimuli
We found that the adaptation modulates SPC tuning curve of the adapter and the neighboring frequencies and shift it toward lower values

Summary

Introduction

Neural adaptation is a brain mechanism that observed in various sensory systems of mammals and amphibians, including the visual (Müller, 1999; Kayser et al, 2009), auditory (Bibikov, 1977; Dean et al, 2005; Anderson et al, 2009; Malmierca et al, 2009; Hagan et al, 2012; Parto Dezfouli and Daliri, 2015), and somatosensory (Katz et al, 2006; Adibi et al, 2013, 2014; Ahmadi et al, 2019) systems. To suppress the attention to repeated stimuli, the adaptation mechanism alters several neural properties. It helps to better detect deviance by increasing the neural sensitivity related to an unexpected change (Ulanovsky et al, 2003). It has been shown that presenting an audio sequence in a random pattern significantly affects the neural responses (Yaron et al, 2012)

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