The reliability of nonlinear least-squares algorithm for data analysis of neural response activity during sinusoidal rotational stimulation in semicircular canal neurons

Abstract

Although many mathematical methods were used to analyze the neural activity under sinusoidal stimulation within linear response range in vestibular system, the reliabilities of these methods are still not reported, especially in nonlinear response range. Here we chose nonlinear least-squares algorithm (NLSA) with sinusoidal model to analyze the neural response of semicircular canal neurons (SCNs) during sinusoidal rotational stimulation (SRS) over a nonlinear response range. Our aim was to acquire a reliable mathematical method for data analysis under SRS in vestibular system. Our data indicated that the reliability of this method in an entire SCNs population was quite satisfactory. However, the reliability was strongly negatively depended on the neural discharge regularity. In addition, stimulation parameters were the vital impact factors influencing the reliability. The frequency had a significant negative effect but the amplitude had a conspicuous positive effect on the reliability. Thus, NLSA with sinusoidal model resulted a reliable mathematical tool for data analysis of neural response activity under SRS in vestibular system and more suitable for those under the stimulation with low frequency but high amplitude, suggesting that this method can be used in nonlinear response range. This method broke out of the restriction of neural activity analysis under nonlinear response range and provided a solid foundation for future study in nonlinear response range in vestibular system.

The head fixation based on skull cap: An improved protocol used in single unit recording in the vestibular system

“…26. Extracellular preamplifier system is connected to the CED Spike2 neural signal acquisition [4 , 5] .…”

“…34. Then the prefer plane of the semicircular canal afferent neuron is brought into the rotation plane of the rotating table by adjusting the gimbaled platform [4 , 5] .…”

“…However, it was no longer qualified to this work because of the extremely high failure rate of data record when the magnitude of motion stimulation was big (e.g. head angular velocity > 180 deg/s) [4] . Our recent study exhibited that the intact dynamic data of semicircular canal afferent neurons in response to the sinusoidal rotation stimulation with an amplitude as big as 300 deg/s, where the mechanical stability for single unit recording was provided by a novel head fixation based on skull cap [5] .…”