Oscillatory activity in forelimb muscles of behaving monkeys evoked by microstimulation in the cerebellar nuclei

2004 ◽  
Vol 361 (1-3) ◽  
pp. 106-110 ◽  
Author(s):  
T.D Aumann ◽  
E.E Fetz
Keyword(s):  
Cerebellar Nuclei ◽  
Oscillatory Activity ◽  
Forelimb Muscles ◽  
Behaving Monkeys

scholarly journals The somatosensory cortex receives information about motor output

2019 ◽  
Vol 5 (7) ◽  
pp. eaaw5388 ◽  
Author(s):  
Tatsuya Umeda ◽  
Tadashi Isa ◽  
Yukio Nishimura
Keyword(s):  
Somatosensory Cortex ◽  
Sensory Feedback ◽  
Somatosensory System ◽  
Motor Output ◽  
Signal Integration ◽  
Movement Initiation ◽  
Online Processing ◽  
Forelimb Muscles ◽  
Behaving Monkeys ◽  
Temporal Profiles

During voluntary movement, the somatosensory system not only passively receives signals from the external world but also actively processes them via interactions with the motor system. However, it is still unclear how and what information the somatosensory system receives during movement. Using simultaneous recordings of activities of the primary somatosensory cortex (S1), the motor cortex (MCx), and an ensemble of afferent neurons in behaving monkeys combined with a decoding algorithm, we reveal the temporal profiles of signal integration in S1. While S1 activity before movement initiation is accounted for by MCx activity alone, activity during movement is accounted for by both MCx and afferent activities. Furthermore, premovement S1 activity encodes information about imminent activity of forelimb muscles slightly after MCx does. Thus, S1 receives information about motor output before the arrival of sensory feedback signals, suggesting that S1 executes online processing of somatosensory signals via interactions with the anticipatory information.

No Clock Signal in the Discharge of Neurons in the Deep Cerebellar Nuclei

1997 ◽  
Vol 77 (4) ◽  
pp. 2232-2234 ◽  
Author(s):  
J. G. Keating ◽  
W. T. Thach
Keyword(s):  
Purkinje Cell ◽  
Fourier Transforms ◽  
Interval Data ◽  
Cerebellar Nuclei ◽  
Clock Signal ◽  
Deep Cerebellar Nuclei ◽  
Isolated Cells ◽  
Complex Spike ◽  
Cell Discharge ◽  
Behaving Monkeys

Keating, J. G. and W. T. Thach. No clock signal in the discharge of neurons in the deep cerebellar nuclei. J. Neurophysiol. 77: 2232–2234, 1997. We examined the spike activity of deep cerebellar nuclear cells recorded from awake, behaving monkeys to determine if there was a tendency for periodic discharge at or near 10 Hz. Data were obtained from four Rhesus monkeys trained to perform either targeted flexions and extensions of the wrist in relation to a visual cue (2 monkeys) or instrumented digit movements and natural reaches (2 monkeys). We determined the interspike intervals of 274 isolated cells. We looked for periodicity by autocorrelating the interval data and Fourier transforming the resulting autocorrelation function. The autocorrelograms and the Fourier transforms failed to reveal periodicity at or near 10 Hz for any cell. This lack of oscillatory discharge in deep nuclear cells of the cerebellum is consistent with our previously reported results that the complex spike of the Purkinje cell is aperiodic. Our failure to observe a clocklike timing signal in awake, behaving animals in either the Purkinje cell complex spike or the deep nuclear cell discharge argues against a popular idea that the inferior olive may act through the cerebellum as a motor clock.

Sensory and Cognitive Components of Auditory Processing in Individuals With Tinnitus

2019 ◽  
Vol 28 (4) ◽  
pp. 834-842
Author(s):  
Harini Vasudevan ◽  
Hari Prakash Palaniswamy ◽  
Ramaswamy Balakrishnan
Keyword(s):  
Selective Attention ◽  
Auditory Processing ◽  
Function Analysis ◽  
Event Related Potential ◽  
Oscillatory Activity ◽  
Default Mode ◽  
Auditory Selective Attention ◽  
Cognitive Components ◽  
Mode Function ◽  
Related Potentials

Purpose The main purpose of the study is to explore the auditory selective attention abilities (using event-related potentials) and the neuronal oscillatory activity in the default mode network sites (using electroencephalogram [EEG]) in individuals with tinnitus. Method Auditory selective attention was measured using P300, and the resting state EEG was assessed using the default mode function analysis. Ten individuals with continuous and bothersome tinnitus along with 10 age- and gender-matched control participants underwent event-related potential testing and 5 min of EEG recording (at wakeful rest). Results Individuals with tinnitus were observed to have larger N1 and P3 amplitudes along with prolonged P3 latency. The default mode function analysis revealed no significant oscillatory differences between the groups. Conclusion The current study shows changes in both the early sensory and late cognitive components of auditory processing. The change in the P3 component is suggestive of selective auditory attention deficit, and the sensory component (N1) suggests an altered bottom-up processing in individuals with tinnitus.

Intraoperative localization of spatially and spectrally distinct resting-state networks in Parkinson’s disease

2020 ◽  
Vol 132 (4) ◽  
pp. 1234-1242 ◽  
Author(s):  
Paolo Belardinelli ◽  
Ramin Azodi-Avval ◽  
Erick Ortiz ◽  
Georgios Naros ◽  
Florian Grimm ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Network Effects ◽  
Brain Activity ◽  
Dynamic Imaging ◽  
Oscillatory Activity ◽  
Network Information ◽  
Novel Approach ◽  
Electrophysiological Recordings ◽  
Intraoperative Localization

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective treatment for symptomatic Parkinson’s disease (PD); the clinical benefit may not only mirror modulation of local STN activity but also reflect consecutive network effects on cortical oscillatory activity. Moreover, STN-DBS selectively suppresses spatially and spectrally distinct patterns of synchronous oscillatory activity within cortical-subcortical loops. These STN-cortical circuits have been described in PD patients using magnetoencephalography after surgery. This network information, however, is currently not available during surgery to inform the implantation strategy.The authors recorded spontaneous brain activity in 3 awake patients with PD (mean age 67 ± 14 years; mean disease duration 13 ± 7 years) during implantation of DBS electrodes into the STN after overnight withdrawal of dopaminergic medication. Intraoperative propofol was discontinued at least 30 minutes prior to the electrophysiological recordings. The authors used a novel approach for performing simultaneous recordings of STN local field potentials (LFPs) and multichannel electroencephalography (EEG) at rest. Coherent oscillations between LFP and EEG sensors were computed, and subsequent dynamic imaging of coherent sources was performed.The authors identified coherent activity in the upper beta range (21–35 Hz) between the STN and the ipsilateral mesial (pre)motor area. Coherence in the theta range (4–6 Hz) was detected in the ipsilateral prefrontal area.These findings demonstrate the feasibility of detecting frequency-specific and spatially distinct synchronization between the STN and cortex during DBS surgery. Mapping the STN with this technique may disentangle different functional loops relevant for refined targeting during DBS implantation.

EEG correlates of cognitive functions and neuropsychiatric disorders: A review of oscillatory activity and neural synchrony abnormalities

2020 ◽  
Vol 16 ◽  
Author(s):  
Meysam Amidfar ◽  
Yong-Ku Kim
Keyword(s):  
Psychiatric Disorders ◽  
Cognitive Functions ◽  
Spectral Power ◽  
Large Body ◽  
Oscillatory Activity ◽  
Brain Oscillations ◽  
Emotional Symptoms ◽  
Obsessive Compulsive ◽  
Neuropsychiatric Diseases ◽  
Obsessive Compulsive Disorders

Background: A large body of evidence suggested that disruption of neural rhythms and synchronization of brain oscillations are correlated with variety of cognitive and perceptual processes. Cognitive deficits are common features of psychiatric disorders that complicate treatment of the motivational, affective and emotional symptoms. Objective: Electrophysiological correlates of cognitive functions will contribute to understanding of neural circuits controlling cognition, the causes of their perturbation in psychiatric disorders and developing novel targets for treatment of cognitive impairments. Methods: This review includes description of brain oscillations in Alzheimer’s disease, bipolar disorder, attentiondeficit/hyperactivity disorder, major depression, obsessive compulsive disorders, anxiety disorders, schizophrenia and autism. Results: The review clearly shows that the reviewed neuropsychiatric diseases are associated with fundamental changes in both spectral power and coherence of EEG oscillations. Conclusion: In this article we examined nature of brain oscillations, association of brain rhythms with cognitive functions and relationship between EEG oscillations and neuropsychiatric diseases. Accordingly, EEG oscillations can most likely be used as biomarkers in psychiatric disorders.

scholarly journals Electrophysiological aftereffects of high-frequency transcranial random noise stimulation (hf-tRNS): an EEG investigation

2021 ◽  
Author(s):  
Filippo Ghin ◽  
Louise O’Hare ◽  
Andrea Pavan
Keyword(s):  
High Frequency ◽  
Discrimination Task ◽  
Temporal Dynamics ◽  
Random Noise ◽  
Decomposition Analysis ◽  
Oscillatory Activity ◽  
Motion Direction ◽  
Time Frequency ◽  
Direction Discrimination ◽  
Transcranial Random Noise Stimulation

AbstractThere is evidence that high-frequency transcranial random noise stimulation (hf-tRNS) is effective in improving behavioural performance in several visual tasks. However, so far there has been limited research into the spatial and temporal characteristics of hf-tRNS-induced facilitatory effects. In the present study, electroencephalogram (EEG) was used to investigate the spatial and temporal dynamics of cortical activity modulated by offline hf-tRNS on performance on a motion direction discrimination task. We used EEG to measure the amplitude of motion-related VEPs over the parieto-occipital cortex, as well as oscillatory power spectral density (PSD) at rest. A time–frequency decomposition analysis was also performed to investigate the shift in event-related spectral perturbation (ERSP) in response to the motion stimuli between the pre- and post-stimulation period. The results showed that the accuracy of the motion direction discrimination task was not modulated by offline hf-tRNS. Although the motion task was able to elicit motion-dependent VEP components (P1, N2, and P2), none of them showed any significant change between pre- and post-stimulation. We also found a time-dependent increase of the PSD in alpha and beta bands regardless of the stimulation protocol. Finally, time–frequency analysis showed a modulation of ERSP power in the hf-tRNS condition for gamma activity when compared to pre-stimulation periods and Sham stimulation. Overall, these results show that offline hf-tRNS may induce moderate aftereffects in brain oscillatory activity.

scholarly journals Resting state alpha oscillatory activity is a valid and reliable marker of schizotypy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jelena Trajkovic ◽  
Francesco Di Gregorio ◽  
Francesca Ferri ◽  
Chiara Marzi ◽  
Stefano Diciotti ◽  
...  
Keyword(s):  
At Risk ◽  
Resting State ◽  
Right Hemisphere ◽  
Normal Population ◽  
Alpha Activity ◽  
Oscillatory Activity ◽  
Loop Current ◽  
Clinical Tool ◽  
Reliable Marker ◽  
The Right

AbstractSchizophrenia is among the most debilitating neuropsychiatric disorders. However, clear neurophysiological markers that would identify at-risk individuals represent still an unknown. The aim of this study was to investigate possible alterations in the resting alpha oscillatory activity in normal population high on schizotypy trait, a physiological condition known to be severely altered in patients with schizophrenia. Direct comparison of resting-state EEG oscillatory activity between Low and High Schizotypy Group (LSG and HSG) has revealed a clear right hemisphere alteration in alpha activity of the HSG. Specifically, HSG shows a significant slowing down of right hemisphere posterior alpha frequency and an altered distribution of its amplitude, with a tendency towards a reduction in the right hemisphere in comparison to LSG. Furthermore, altered and reduced connectivity in the right fronto-parietal network within the alpha range was found in the HSG. Crucially, a trained pattern classifier based on these indices of alpha activity was able to successfully differentiate HSG from LSG on tested participants further confirming the specific importance of right hemispheric alpha activity and intrahemispheric functional connectivity. By combining alpha activity and connectivity measures with a machine learning predictive model optimized in a nested stratified cross-validation loop, current research offers a promising clinical tool able to identify individuals at-risk of developing psychosis (i.e., high schizotypy individuals).

scholarly journals Mapping of long-term cognitive and motor deficits in pediatric cerebellar brain tumor survivors into a cerebellar white matter atlas

2021 ◽  
Author(s):  
Frederik Grosse ◽  
Stefan Mark Rueckriegel ◽  
Ulrich-Wilhelm Thomale ◽  
Pablo Hernáiz Driever
Keyword(s):  
Brain Tumor ◽  
Executive Function ◽  
Cognitive Function ◽  
White Matter ◽  
Cerebellar Nuclei ◽  
Motor Deficits ◽  
Deep Cerebellar Nuclei ◽  
Cerebellar White Matter ◽  
Lesion Symptom Mapping

Abstract Purpose Diaschisis of cerebrocerebellar loops contributes to cognitive and motor deficits in pediatric cerebellar brain tumor survivors. We used a cerebellar white matter atlas and hypothesized that lesion symptom mapping may reveal the critical lesions of cerebellar tracts. Methods We examined 31 long-term survivors of pediatric posterior fossa tumors (13 pilocytic astrocytoma, 18 medulloblastoma). Patients underwent neuronal imaging, examination for ataxia, fine motor and cognitive function, planning abilities, and executive function. Individual consolidated cerebellar lesions were drawn manually onto patients’ individual MRI and normalized into Montreal Neurologic Institute (MNI) space for further analysis with voxel-based lesion symptom mapping. Results Lesion symptom mapping linked deficits of motor function to the superior cerebellar peduncle (SCP), deep cerebellar nuclei (interposed nucleus (IN), fastigial nucleus (FN), ventromedial dentate nucleus (DN)), and inferior vermis (VIIIa, VIIIb, IX, X). Statistical maps of deficits of intelligence and executive function mapped with minor variations to the same cerebellar structures. Conclusion We identified lesions to the SCP next to deep cerebellar nuclei as critical for limiting both motor and cognitive function in pediatric cerebellar tumor survivors. Future strategies safeguarding motor and cognitive function will have to identify patients preoperatively at risk for damage to these critical structures and adapt multimodal therapeutic options accordingly.

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