Spectral analysis of instantaneous frequency responses to sinusoidal stimulation in cutaneous mechanoreceptor afferent units of frogs.

Abstract

While applying the Fast Fourier Transform to the instantaneous frequency responses to sinusoidal indentations of the cutaneous mechanoreceptor afferent units in frogs, we examined quantitatively the dynamic responses of these units. In two kinds of slowly adapting (SA) units, i.e., frog type I and frog type II units, and in rapidly adapting (RA) type I units, the instantaneous frequency responses could be reconstructed by summation of the DC component and the major 3-5 harmonics in the power spectra. In both types of SA units, the fundamental wave was the largest in power of the spectrum, but in the RA units, the 2nd harmonic was the largest. In SA units, the phase of the fundamental wave advanced by 20-55° relative to the sinusoidal stimulation, but the phase of the 2nd harmonic of the RA units advanced by ca. 90°. The magnitude of each component in the power spectra, especially the fundamental wave of the two SA units and the 2nd harmonics of the RA unit, increased with an increase in stimulus amplitude and frequency. The phases of thee harmonics in both SA and RA types were fairly constant over varying amplitudes and frequencies of sinusoidal stimulation. The present findings indicate that both the frog type I and type II cutaneous mechanoreceptor afferent units detect both indentation magnitude and positive velocity, and that the RA type I cutaneous mechanoreceptor afferent units detect the stimulus velocity.

Phase Locking to High Frequencies in the Auditory Nerve and Cochlear Nucleus Magnocellularis of the Barn Owl,Tyto alba

“…Phase locking encodes the temporal structure of stimuli, from slow modulations to fine structure in the microsecond range in different sensory systems (for example, see Taniguchi and Ogawa, 1987;Surlykke et al, 1988;Heiligenberg, 1989;Wubbels, 1992;Carr, 1993b). The barn owl has become an important model for the study of extremely fast temporal processing based on neural phase locking.…”

Simultaneous spike-time locking to multiple frequencies

“…Phase locking of neural firing to external and internal signals is an ubiquitous and important physiological mechanism in the brain (Köppl, 1997;Surlykke et al, 1988;Joris and Smith, 2008;Taniguchi and Hisashu, 1987;Bastian, 1981;Chacron et al, 2000;Ratnam and Nelson, 2000;Montemurro et al, 2008;Martin and Schröder, 2016;Ewert et al, 2008;Wubbels, 1992;Buzsáki and Draguhn, 2004). It allows neurons to encode the temporal structure of stimuli and decode important stimulus information from minute temporal differences in spike arrivals (Köppl, 1997).…”

“…Phase locking in neuronal activity is observed when neurons fire action potentials at or around a particular phase of a periodic signal. It is a widespread phenomenon in neural systems and has been studied intensively in the auditory (Köppl, 1997;Surlykke et al, 1988;Joris and Smith, 2008;Kayser et al, 2012Kayser et al, , 2009), mechano-sensory (Taniguchi and Hisashu, 1987), electrosensory (Bastian, 1981;Chacron et al, 2000;Ratnam and Nelson, 2000;van Hemmen et al, 2011), visual Martin and Schröder, 2016;Belitski et al, 2008), vibrissial (Ewert et al, 2008), and the lateral line system (Wubbels, 1992). The phase of spikes can carry important information about the timing of external signals or provide additional information in time-scale multiplexed neural codes (Panzeri et al, 2010;Bullock, 1997;Lisman, 2005;Belitski et al, 2008;Kayser et al, 2009).…”

Multiscale analysis of neural spike trains

“…The models discussed in this paper assume that the initial phases ω ( 0 ) are constant throughout the study period [0, T ). This model can be useful for the firing activity of phase‐locked neurons . Notice that the notion of phase can be used differently across the neuroscience literature.…”