Mechanisms of imbalanced frontostriatal functional connectivity in obsessive-compulsive disorder.

The diagnosis of obsessive-compulsive disorder (OCD) has been linked with changes in frontostriatal resting-state connectivity. However, replication of prior findings is lacking, and the mechanistic understanding of these effects is incomplete. To confirm and advance knowledge on changes in frontostriatal functional connectivity in OCD, participants with OCD and matched healthy controls underwent resting-state functional, structural and diffusion neuroimaging.

Functional brain activity constrained by structural connectivity reveals cohort-specific features for serum neurofilament light chain.

Background: Neuro-axonal brain damage releases neurofilament light chain (NfL) proteins, which enter the blood. Serum NfL has recently emerged as a promising biomarker for grading axonal damage, monitoring treatment responses, and prognosis in neurological diseases. Importantly, serum NfL levels also increase with aging, and the interpretation of serum NfL levels in neurological diseases is incomplete due to lack of a reliable model for age-related variation in serum NfL levels in healthy subjects.

Features importance in seizure classification using scalp EEG reduced to single timeseries.

Seizure detection and seizure-type classification are best performed using intra-cranial or full-scalp electroencephalogram (EEG). In embedded wearable systems however, recordings from only a few electrodes are available, reducing the spatial resolution of the signals to a handful of timeseries at most. Taking this constraint into account, we tested the performance of multiple classifiers using a subset of the EEG recordings by selecting a single trace from the montage or performing a dimensionality reduction over each hemispherical space.

Robustness of connectome harmonics to local gray matter and long-range white matter connectivity changes.

Recently, it has been proposed that the harmonic patterns emerging from the brain's structural connectivity underlie the resting state networks of the human brain. These harmonic patterns, termed connectome harmonics, are estimated as the Laplace eigenfunctions of the combined gray and white matters connectivity matrices and yield a connectome-specific extension of the well-known Fourier basis. However, it remains unclear how topological properties of the combined connectomes constrain the precise shape of the connectome harmonics and their relationships to the resting state networks.

Classification of TMS evoked potentials using ERP time signatures and SVM versus deep learning.

Modeling transcranial magnetic stimulation (TMS) evoked potentials (TEP) begins with classification of stereotypical single-pulse TMS responses in order to select validation targets for generative dynamical models. Several dimensionality reduction techniques are commonly in use to extract statistically independent features from experimental data for regression against model parameters. Here, we first designed a 3-dimensional feature space based on commonly described event-related potentials (ERP) from the literature.

Cortico-Striatal Cross-Frequency Coupling and Gamma Genesis Disruptions in Huntington's Disease Mouse and Computational Models.

Abnormal gamma band power across cortex and striatum is an important phenotype of Huntington's disease (HD) in both patients and animal models, but neither the origin nor the functional relevance of this phenotype is well understood. Here, we analyzed local field potential (LFP) activity in freely behaving, symptomatic R6/2 and Q175 mouse models and corresponding wild-type (WT) controls. We focused on periods of quiet rest, which show strong γ activity in HD mice.

Computational modeling of seizure dynamics using coupled neuronal networks: factors shaping epileptiform activity.

Epileptic seizure dynamics span multiple scales in space and time. Understanding seizure mechanisms requires identifying the relations between seizure components within and across these scales, together with the analysis of their dynamical repertoire. Mathematical models have been developed to reproduce seizure dynamics across scales ranging from the single neuron to the neural population.

Modern concepts of seizure modeling.

Seizures are complex phenomena spanning multiple spatial and temporal scales, from ion dynamics to communication between brain regions, from milliseconds (spikes) to days (interseizure intervals). Because of the existence of such multiple scales, the experimental evaluation of the mechanisms underlying the initiation, propagation, and termination of epileptic seizures is a difficult problem. Theoretical models and numerical simulations provide new tools to investigate seizure mechanisms at multiple scales.

The head-mounted microscope.

Microsurgical equipment has greatly advanced since the inception of the microscope into the operating room. These advancements have allowed for superior surgical precision and better post-operative results. This study focuses on the use of the Leica HM500 head-mounted microscope for the operating phonosurgeon.

Activation of phospholipase D by endothelin-1 in rat myometrium. Role of calcium and protein kinase C.

In rat myometrium labeled with [3H]myristic acid, endothelin (ET)-1 via ET(A) receptors stimulated, in the presence of 0.3% butanol, the formation of [3H]phosphatidylbutanol ([3H]PBut) as a result of phospholipase D activity. Fluoroaluminates increased [3H]PBut generation, which indicated that a heterotrimeric G protein was involved.

ETA receptors mediate activation of phospholipases C and D in rat myometrium.

In estrogen-treated rat myometrium, endothelin-1 (ET-1) activated both the phospholipase C (PLC) which degrades PtdInsP2, resulting in an increased accumulation of inositol phosphates, and the phospholipase D pathway (PLD) as evidenced in the presence of butanol by an increased production of phosphatidylbutanol (PBut). Both ET-1 effects displayed similar concentration dependencies (EC50 50 nM) and were mediated by ET(A) receptors in that they were antagonized by BQ123 and were elicited by ET-3 with a rank order of potency ET-1 >> ET-3. Bombesin, another activator of the PLC/PtdInsP2 pathway, also increased PBut accumulation.

Endothelin receptor type A signals both the accumulation of inositol phosphates and the inhibition of cyclic AMP generation in rat myometrium: stimulation and desensitization.

In estradiol-dominated rat myometrium, endothelin (ET)-1 caused contraction and increased the accumulation of [3H]inositol phosphates (EC50 = 70 nM), with the sequential generation of inositol trisphosphate, inositol bisphosphate, and inositol monophosphate. There was a coincident early decrease in phosphatidyl-inositol bisphosphate. The ET-1 stimulatory effect was pertussis toxin insensitive, suggesting an activation of phospholipase C via Gq/G11 proteins.