History information emerges in the cortex during learning.

We learn from our experience but the underlying neuronal mechanisms incorporating past information to facilitate learning is relatively unknown. Specifically, which cortical areas encode history-related information and how is this information modulated across learning? To study the relationship between history and learning, we continuously imaged cortex-wide calcium dynamics as mice learn to use their whiskers to discriminate between two different textures. We mainly focused on comparing the same trial type with different trial history, that is, a different preceding trial.

Deep Brain Stimulation Can Differentiate Subregions of the Human Subthalamic Nucleus Area by EEG Biomarkers.

Precise lead localization is crucial for an optimal clinical outcome of subthalamic nucleus (STN) deep brain stimulation (DBS) treatment in patients with Parkinson's disease (PD). Currently, anatomical measures, as well as invasive intraoperative electrophysiological recordings, are used to locate DBS electrodes. The objective of this study was to find an alternative electrophysiology tool for STN DBS lead localization.

Machine learning-based personalized subthalamic biomarkers predict ON-OFF levodopa states in Parkinson patients.

Adaptive deep brain stimulation (aDBS) based on subthalamic nucleus (STN) electrophysiology has recently been proposed to improve clinical outcomes of DBS for Parkinson's disease (PD) patients. Many current models for aDBS are based on one or two electrophysiological features of STN activity, such as beta or gamma activity. Although these models have shown interesting results, we hypothesized that an aDBS model that includes many STN activity parameters will yield better clinical results.

Independently together: subthalamic theta and beta opposite roles in predicting Parkinson's tremor.

Tremor is a core feature of Parkinson's disease and the most easily recognized Parkinsonian sign. Nonetheless, its pathophysiology remains poorly understood. Here, we show that multispectral spiking activity in the posterior-dorso-lateral oscillatory (motor) region of the subthalamic nucleus distinguishes resting tremor from the other Parkinsonian motor signs and strongly correlates with its severity.

Movement context modulates neuronal activity in motor and limbic-associative domains of the human parkinsonian subthalamic nucleus.

The subthalamic nucleus (STN), a preferred target for treating movement disorders, has a crucial role in inhibition and execution of movement. To better understand the mechanism of movement regulation in the STN of Parkinson's disease patients, we compared the same movement with different context, facilitation vs. inhibition context.

Theta-alpha oscillations characterize emotional subregion in the human ventral subthalamic nucleus.

Background: Therapeutic outcomes of STN-DBS for movement and psychiatric disorders depend on electrode location within the STN. Electrophysiological and functional mapping of the STN has progressed considerably in the past years, identifying beta-band oscillatory activity in the dorsal STN as a motor biomarker. It also has been suggested that STN theta-alpha oscillations, involved in impulse control and action inhibition, have a ventral source.

Subthalamic theta activity: a novel human subcortical biomarker for obsessive compulsive disorder.

Obsessive-compulsive disorder (OCD) is a common and serious psychiatric disorder. Although subthalamic nucleus deep brain stimulation (DBS) has been studied as a treatment for OCD patients the underlying mechanism of this treatment and the optimal method of stimulation are unknown. To study the neural basis of subthalamic nucleus DBS in OCD patients we used a novel, implantable DBS system with long-term local field potential sensing capability.

Microelectrode Recordings Validate the Clinical Visualization of Subthalamic-Nucleus Based on 7T Magnetic Resonance Imaging and Machine Learning for Deep Brain Stimulation Surgery.

Background: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a proven and effective therapy for the management of the motor symptoms of Parkinson's disease (PD). While accurate positioning of the stimulating electrode is critical for success of this therapy, precise identification of the STN based on imaging can be challenging. We developed a method to accurately visualize the STN on a standard clinical magnetic resonance imaging (MRI).

Local vs. volume conductance activity of field potentials in the human subthalamic nucleus.

Subthalamic nucleus field potentials have attracted growing research and clinical interest over the last few decades. However, it is unclear whether subthalamic field potentials represent locally generated neuronal subthreshold activity or volume conductance of the organized neuronal activity generated in the cortex. This study aimed at understanding of the physiological origin of subthalamic field potentials and determining the most accurate method for recording them.

Anesthesia reduces discharge rates in the human pallidum without changing the discharge rate ratio between pallidal segments.

Classical rate models of basal ganglia circuitry associate discharge rate of the globus pallidus external and internal segments (GPe, GPi respectively) solely with dopaminergic state and predict an inverse ratio between the discharge rates of the two pallidal segments. In contrast, the effects of other rate modulators such as general anesthesia (GA) on this ratio have been ignored. To respond to this need, we recorded the neuronal activity in the GPe and GPi in awake and anesthetized human patients with dystonia (57 and 53 trajectories respectively) and in awake patients with Parkinson's disease (PD, 16 trajectories) undergoing deep brain stimulation procedures.

Constant Current versus Constant Voltage Subthalamic Nucleus Deep Brain Stimulation in Parkinson's Disease.

Background: Subthalamic nucleus (STN) deep brain stimulation (DBS) is an established therapy for advanced Parkinson's disease (PD). Motor efficacy and safety have been established for constant voltage (CV) devices and more recently for constant current (CC) devices. CC devices adjust output voltage to provide CC stimulation irrespective of impedance fluctuation, while the current applied by CV stimulation depends on the impedance that may change over time.

Neurons in both pallidal segments change their firing properties similarly prior to closure of the eyes.

Current anatomical models of the cortico-basal ganglia (BG) network predict reciprocal discharge patterns between the external and internal segments of the globus pallidus (GPe and GPi, respectively), as well as cortical driving of BG activity. However, physiological studies revealing similarity in the transient responses of GPe and GPi neurons cast doubts on these predictions. Here, we studied the discharge properties of GPe, GPi, and primary motor cortex neurons of two monkeys in two distinct states: when eyes are open versus when they are closed.

Low-pass filter properties of basal ganglia cortical muscle loops in the normal and MPTP primate model of parkinsonism.

Oscillatory bursting activity is commonly found in the basal ganglia (BG) and the thalamus of the parkinsonian brain. The frequency of these oscillations is often similar to or higher than that of the parkinsonian tremor, but their relationship to the tremor and other parkinsonian symptoms is still under debate. We studied the frequency dependency of information transmission in the cortex-BG and cortex-periphery loops by recording simultaneously from multiple electrodes located in the arm-related primary motor cortex (MI) and in the globus pallidus (GP) of two vervet monkeys before and after 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment and induction of parkinsonian symptoms.

Basal ganglia oscillations and pathophysiology of movement disorders.

Low frequency rest tremor is one of the cardinal signs of Parkinson's disease and some of its animal models. Current physiological studies and models of the basal ganglia differ as to which aspects of neuronal activity are crucial to the pathophysiology of Parkinson's disease. There is evidence that neural oscillations and synchronization play a central role in the generation of the disease.