Objective: Machado-Joseph disease (MJD), an autosomal dominant spinocerebellar degeneration caused by an expanded CAG repeat on chromosome 14q32.1, is a disorder with wide range of neurological findings and brain regions involved. Studies evaluating neurophysiological parameters related to sensory gating in MJD are lacking.
Methods: This study intends to investigate P50 suppression, an auditory mid-latency evoked potential in a test-conditioning paradigm, considered as an index of sensory gating function. Twelve patients with MJD, 24 normal subjects and 12 schizophrenic patients were evaluated.
Results: MJD subjects had higher P50 ratios as compared to normal subjects (76.2 vs. 42.1%, P = 0.001), but similar to the group of schizophrenic patients. The difference from controls was due to greater test amplitudes (3.4 vs. 2.0 microV, P = 0.002), rather than to conditioning amplitudes. Latencies were higher for the MJD subjects than for controls (60.4 vs. 56.1 ms, P = 0.016).
Conclusions: MJD may present sensory gating dysfunction. However, the pattern of this dysfunction seems to slightly differ from that classically found in schizophrenia, were both test and conditioning amplitudes seem to be implicated.
Significance: These results point out the P50 paradigm as a potential tool for further neurophysiological surveying in MJD.
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http://dx.doi.org/10.1016/j.clinph.2004.04.025 | DOI Listing |
Brain Sci
December 2024
Neuroscience Center Zurich, University and ETH Zurich, CH-8091 Zurich, Switzerland.
Background/objectives: The auditory middle-latency responses (AMLRs) assess central sensory processing beyond the brainstem and serve as a measure of sensory gating. They have clinical relevance in the diagnosis of neurological conditions. In this study, magnitude and habituation of the AMLRs were tested for sensitivity and specificity in classifying dizzy patients with vestibular migraine (VM) and post-concussive syndrome.
View Article and Find Full Text PDFPLoS Biol
January 2025
Department of Neurology, School of Medicine and Health, Technical University of Munich (TUM), Munich, Germany.
Pain is closely linked to alpha oscillations (8 < 13 Hz) which are thought to represent a supra-modal, top-down mediated gating mechanism that shapes sensory processing. Consequently, alpha oscillations might also shape the cerebral processing of nociceptive input and eventually the perception of pain. To test this mechanistic hypothesis, we designed a sham-controlled and double-blind electroencephalography (EEG)-based neurofeedback study.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Modelling of Cognitive Processes, Berlin Institute of Technology, Berlin 10587, Germany.
Neuronal processing of external sensory input is shaped by internally generated top-down information. In the neocortex, top-down projections primarily target layer 1, which contains NDNF (neuron-derived neurotrophic factor)-expressing interneurons and the dendrites of pyramidal cells. Here, we investigate the hypothesis that NDNF interneurons shape cortical computations in an unconventional, layer-specific way, by exerting presynaptic inhibition on synapses in layer 1 while leaving synapses in deeper layers unaffected.
View Article and Find Full Text PDFJ Gen Physiol
March 2025
Institute for Neurophysiology, Uniklinik RWTH Aachen University, Aachen, Germany.
Voltage-gated sodium channels (VGSCs) in the peripheral nervous system shape action potentials (APs) and thereby support the detection of sensory stimuli. Most of the nine mammalian VGSC subtypes are expressed in nociceptors, but predominantly, three are linked to several human pain syndromes: while Nav1.7 is suggested to be a (sub-)threshold channel, Nav1.
View Article and Find Full Text PDFActa Neurobiol Exp (Wars)
January 2025
Department of Adult Psychiatry, Poznan University of Medical Sciences, Poznan, Poland.
The article provides a review of the sensory processing (SP) phenomenon, its origins, theoretical models, and neurophysiological foundations. Initiated by A. Jean Ayres' research on sensory integration in the 1960s and 70s, this field has evolved, leading to the development of concepts such as Winnie Dunn's four quadrant model and Miller's ecological model of sensory modulation.
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