Processing of amplitude modulated sounds in the medial geniculate body of squirrel monkeys

Preuss, A. W.; Müller-Preuß, P.

doi:10.1007/bf00228890

Cited by 60 publications

(39 citation statements)

References 13 publications

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“…It is also important to consider the modulation frequencies that did not generate the expected suppression produced when S1 and S2 carrier frequencies matched. In some cases, the suppression probably mirrored the modulation frequency tuning of inputs that have already been formed at subcortical levels (Creutzfeldt et al 1980;Langner and Schreiner 1988;Preuss and Muller-Preuss 1990). However, many S1 stimuli drove the neuron and still did not produce suppression, supporting the assertion that suppression differed from spiking habituation.…”

Section: Sensitivity To S1 Modulation Frequencymentioning

confidence: 69%

Long-Lasting Modulation by Stimulus Context in Primate Auditory Cortex

Bartlett

Wang²

2005

Journal of Neurophysiology

146

110

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A sound embedded in an acoustic stream cannot be unambiguously segmented and identified without reference to its stimulus context. To understand the role of stimulus context in cortical processing, we investigated the responses of auditory cortical neurons to 2-sound sequences in awake marmosets, with a focus on stimulus properties other than carrier frequency. Both suppressive and facilitatory modulations of cortical responses were observed by using combinations of modulated tone and noise stimuli. The main findings are as follows. 1) Preceding stimuli could suppress or facilitate responses to succeeding stimuli for durations >1 s. These long-lasting effects were dependent on the duration, sound level, and modulation parameters of the preceding stimulus, in addition to the carrier frequency. They occurred regardless of whether the 2 stimuli were separated by a silent interval. 2) Suppression was often tuned such that preceding stimuli whose parameters were similar to succeeding stimuli produced the strongest suppression. However, the responses of many units could be suppressed, although often weaker, even when the 2 stimuli were dissimilar. In some cases, only a dissimilar preceding stimulus produced suppression in the responses to the succeeding stimulus. 3) In contrast to suppression, facilitation of responses to succeeding stimuli by the preceding stimulus was usually strongest when the 2 stimuli were dissimilar. 4) There was no clear correlation between the firing rate evoked by the preceding stimulus and the change in the firing rate evoked by the succeeding stimulus, indicating that the observed suppression was not simply a result of habituation or spike adaptation. These results demonstrate that persistent modulations of the responses of an auditory cortical neuron to a given stimulus can be induced by preceding stimuli. Decreases or increases of responses to the succeeding stimuli are dependent on the spectral, temporal, and intensity properties of the preceding stimulus. This indicates that cortical auditory responses to a sound are not static, but instead depend on the stimulus context in a stimulus-specific manner. The long-lasting impact of stimulus context and the prevalence of facilitation suggest that such cortical response properties are important for auditory processing beyond forward masking, such as for auditory streaming and segregation.

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Section: Sensitivity To S1 Modulation Frequencymentioning

confidence: 69%

Long-Lasting Modulation by Stimulus Context in Primate Auditory Cortex

Bartlett

Wang²

2005

Journal of Neurophysiology

146

110

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“…Another simplification we employed was to implement thalamic activity in response to AM stimuli as a smooth, rectified sinusoid that mirrored the stimulus (Eq. 4); thalamic activity in vivo shows more complex temporal profiles as well as diverse response tuning (Bartlett and Wang 2007;Creutzfeldt et al 1980;Miller et al 2002;Preuss and Muller-Preuss 1990). Nonetheless, the model provides insight into the qualitative effects that the modeled synaptic and intrinsic properties may have on cortical responses.…”

Section: Discussionmentioning

confidence: 95%

Characterization of thalamocortical responses of regular-spiking and fast-spiking neurons of the mouse auditory cortex in vitro and in silico

Schiff

Reyes

2012

Journal of Neurophysiology

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We use a combination of in vitro whole cell recordings and computer simulations to characterize the cellular and synaptic properties that contribute to processing of auditory stimuli. Using a mouse thalamocortical slice preparation, we record the intrinsic membrane properties and synaptic properties of layer 3/4 regular-spiking (RS) pyramidal neurons and fast-spiking (FS) interneurons in primary auditory cortex (AI). We find that postsynaptic potentials (PSPs) evoked in FS cells are significantly larger and depress more than those evoked in RS cells after thalamic stimulation. We use these data to construct a simple computational model of the auditory thalamocortical circuit and find that the differences between FS and RS cells observed in vitro generate model behavior similar to that observed in vivo. We examine how feedforward inhibition and synaptic depression affect cortical responses to time-varying inputs that mimic sinusoidal amplitude-modulated tones. In the model, the balance of cortical inhibition and thalamic excitation evolves in a manner that depends on modulation frequency (MF) of the stimulus and determines cortical response tuning.

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“…The synchronization of responses to SAM stimuli in the IC, the SPON's main projection target, is limited to MRs of ~ 200 Hz in all mammalian species tested, including rats (Rees and Moller, 1987), guinea pigs (Rees and Palmer, 1989), gerbils (Krishna and Semple, 2000), squirrel monkeys (MullerPreuss et al, 1994), and mice , and is similarly limited in the medial geniculate body (Creutzfeldt et al, 1980;Preuss and Muller-Preuss, 1990), another recently identified projection target of the SPON (Jin and Berrebi, 2006). Therefore, by providing a highly synchronized inhibitory input, the SPON may serve to shape responses in its target nuclei by segmenting their ongoing responses.…”

Section: Functional Implicationsmentioning

confidence: 99%

Encoding of temporal features of auditory stimuli in the medial nucleus of the trapezoid body and superior paraolivary nucleus of the rat

2008

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Neurons in the superior paraolivary nucleus (SPON) respond to the offset of pure tones with a brief burst of spikes. Medial nucleus of the trapezoid body (MNTB) neurons, which inhibit the SPON, produce a sustained pure tone response followed by an offset response characterized by a period of suppressed spontaneous activity. This MNTB offset response is duration dependent and critical to the formation of SPON offset spikes (Kadner et al., 2006;Kulesza, Jr. et al., 2007). Here we examine the temporal resolution of the MNTB/SPON circuit by assessing its capability to i) detect gaps in tones, and ii) synchronize to sinusoidally amplitude modulated (SAM) tones. Gap detection was tested by presenting two identical pure tone markers interrupted by gaps ranging from 0-25 ms duration. SPON neurons responded to the offset of the leading marker even when the two markers were separated only by their ramps (i.e., a 0 ms gap); longer gap durations elicited progressively larger responses. MNTB neurons produced an offset response at gap durations of 2 ms or longer, with a subset of neurons responding to 0 ms gaps. SAM tone stimuli used the unit's characteristic frequency as a carrier, and modulation rates ranged from 40-1160 Hz. MNTB neurons synchronized to modulation rates up to ~1 KHz, whereas spiking of SPON neurons decreased sharply at modulation rates ≥ 400 Hz. Modulation transfer functions based on spike count were all-pass for MNTB neurons and low-pass for SPON neurons; the modulation transfer functions based on vector strength were low-pass for both nuclei, with a steeper cut-off for SPON neurons. Thus, the MNTB/SPON circuit encodes episodes of low stimulus energy, such as gaps in pure tones and troughs in amplitude modulated tones. The output of this circuit consists of brief SPON spiking episodes; their potential effects on the auditory midbrain and forebrain are discussed.

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Processing of amplitude modulated sounds in the medial geniculate body of squirrel monkeys

Cited by 60 publications

References 13 publications

Long-Lasting Modulation by Stimulus Context in Primate Auditory Cortex

Long-Lasting Modulation by Stimulus Context in Primate Auditory Cortex

Characterization of thalamocortical responses of regular-spiking and fast-spiking neurons of the mouse auditory cortex in vitro and in silico

Encoding of temporal features of auditory stimuli in the medial nucleus of the trapezoid body and superior paraolivary nucleus of the rat

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