rudyvdbrink/CitationDatabase huggingface dataset:
Discovery of Molecular Interactions of the Human Melanocortin-4 Receptor (hMC4R) Asp189 (D189) Amino Acid with the Endogenous G-Protein-Coupled Receptor (GPCR) Antagonist Agouti-Related Protein (AGRP) Provides Insights to AGRP's Inverse Agonist Pharmacology at the hMC4R.
ACS chemical neuroscience, 2021

The melanocortin receptors (MCRs) are important for numerous biological pathways, including feeding behavior and energy homeostasis. In addition to endogenous peptide agonists, this receptor family has two naturally occurring endogenous antagonists, agouti and agouti-related protein (AGRP). At the melanocortin-4 receptor (MC4R), the AGRP ligand functions as an endogenous inverse agonist in the absence of agonist and as a competitive antagonist in the presence of agonist. At the melanocortin-3 receptor (MC3R), AGRP functions solely as a competitive antagonist in the presence of agonist. The molecular interactions that differentiate AGRP's inverse agonist activity at the MC4R have remained elusive until the findings reported herein. Upon the basis of homology molecular modeling approaches, we previously postulated a unique interaction between the D189 position of the hMC4R and Asn114 of AGRP. To further test this hypothesis, six D189 mutant hMC4Rs (D189A, D189E, D189N, D189Q, D189S, and D189K) were generated and pharmacologically characterized resulting in the discovery of differences in inverse agonist activity of AGRP and an 11 macrocyclic compound library. These data support the hypothesized interaction between the hMC4R D189 position and Asn114 residue of AGRP and define critical ligand-receptor molecular interactions responsible for the inverse agonist activity of AGRP at the hMC4R.
Timing of light pulses and photoperiod on the diurnal rhythm of hippocampal neuronal morphology of Siberian hamsters.
Neuroscience, 2014

Rapid remodeling of neurons provides the brain with flexibility to adjust to environmental fluctuations. In Siberian hamsters, hippocampal dendritic morphology fluctuates across the day. To reveal the regulatory mechanism of diurnal remodeling of hippocampal neurons, we investigated the effects of light signals applied under different photoperiodic conditions on dendritic morphology. A 4-h dark pulse during the morning of long days (LD) increased basilar dendritic length, as well as complexity of basilar dendrites of neurons in the CA1. A light pulse during the late night in short days (SD) reduced basilar dendrite branching and increased primary apical dendrites of CA1 neurons. Spine density of dentate gyrus (DG) dendrites was increased by a dark pulse in LD and spine density of CA1 basilar dendrites was decreased by a light pulse in SD. These results indicate that light signals induce rapid remodeling of dendritic morphology in a hippocampal subregion-specific manner. A light pulse in SD decreased hippocampal expression of fetal liver kinase 1 (Flk1), a receptor for vascular endothelial growth factor (VEGF), raising the possibility that VEGF-FLK1 signaling might be involved in the rapid decrease of branching or spine density of CA1 basilar dendrites by light.
Efficacy of curcumin for age-associated cognitive decline: a narrative review of preclinical and clinical studies.
GeroScience, 2018

Processes such as aberrant redox signaling and chronic low-grade systemic inflammation have been reported to modulate age-associated pathologies such as cognitive impairment. Curcumin, the primary therapeutic component of the Indian spice, Turmeric (Curcuma longa), has long been known for its strong anti-inflammatory and antioxidant activity attributable to its unique molecular structure. Recently, an interest in this polyphenol as a cognitive therapeutic for the elderly has emerged. The purpose of this paper is to critically review preclinical and clinical studies that have evaluated the efficacy of curcumin in ameliorating and preventing age-associated cognitive decline and address the translational progress of preclinical to clinical efficacy. PubMed, semantic scholar, and Google scholar searches were used for preclinical studies; and clinicaltrials.gov , the Australian and New Zealand clinical trials registry, and PubMed search were used to select relevant completed clinical studies. Results from preclinical studies consistently demonstrate curcumin and its analogues to be efficacious for various aspects of cognitive impairment and processes that contribute to age-associated cognitive impairment. Results of published clinical studies, while mixed, continue to show promise for curcumin's use as a therapeutic for cognitive decline but overall remain inconclusive at this time. Both in vitro and in vivo studies have found that curcumin can significantly decrease oxidative stress, systemic inflammation, and obstruct pathways that activate transcription factors that augment these processes. Future clinical studies would benefit from including evaluation of peripheral and cerebrospinal fluid biomarkers of dementia and behavioral markers of cognitive decline, as well as targeting the appropriate population.
Glycogenolysis Is Crucial for Astrocytic Glycogen Accumulation and Brain Damage after Reperfusion in Ischemic Stroke.
iScience, 2020

Astrocytic glycogen is an important energy reserve in the brain and is believed to supply fuel during energy crisis. However, the pattern of glycogen metabolism in ischemic stroke and its potential therapeutic impact on neurological outcomes are still unknown. Here, we found extensive brain glycogen accumulation after reperfusion in ischemic stroke patients and primates. Glycogenolytic dysfunction in astrocytes is responsible for glycogen accumulation, caused by inactivation of the protein kinase A (PKA)-glycogen phosphorylase kinase (PhK)-glycogen phosphorylase (GP) cascade accompanied by the activation of glycogen synthase kinase-3β (GSK3β). Genetic or pharmacological augmentation of astrocytic GP could promote astrocyte and neuron survival and improve neurological behaviors. In addition, we found that insulin exerted a neuroprotective effect, at least in part by rescuing the PKA-PhK-GP cascade to maintain homeostasis of glycogen metabolism during reperfusion. Together, our findings suggest a promising intervention for undesirable outcomes in ischemic stroke.
Development and Validation of a Dynamic Risk Prediction Model to Forecast Psychosis Onset in Patients at Clinical High Risk.
Schizophrenia bulletin, 2020

The prediction of outcomes in patients at Clinical High Risk for Psychosis (CHR-P) almost exclusively relies on static data obtained at a single snapshot in time (ie, baseline data). Although the CHR-P symptoms are intrinsically evolving over time, available prediction models cannot be dynamically updated to reflect these changes. Hence, the aim of this study was to develop and internally validate a dynamic risk prediction model (joint model) and to implement this model in a user-friendly online risk calculator. Furthermore, we aimed to explore the prognostic performance of extended dynamic risk prediction models and to compare static with dynamic prediction. One hundred ninety-six CHR-P patients were recruited as part of the "Basel Früherkennung von Psychosen" (FePsy) study. Psychopathology and transition to psychosis was assessed at regular intervals for up to 5 years using the Brief Psychiatric Rating Scale-Expanded (BPRS-E). Various specifications of joint models were compared with regard to their cross-validated prognostic performance. We developed and internally validated a joint model that predicts psychosis onset from BPRS-E disorganization and years of education at baseline and BPRS-E positive symptoms during the follow-up with good prognostic performance. The model was implemented as online risk calculator (http://www.fepsy.ch/DPRP/). The use of extended joint models slightly increased the prognostic accuracy compared to basic joint models, and dynamic models showed a higher prognostic accuracy than static models. Our results confirm that extended joint modeling could improve the prediction of psychosis in CHR-P patients. We implemented the first online risk calculator that can dynamically update psychosis risk prediction.
Mere surgery will not cure cluster headache--implications for neurostimulation.
Cephalalgia : an international journal of headache, 2011

This case study concerns a patient with primary chronic cluster headache, who was unresponsive to all treatments and consecutively underwent hypothalamic deep brain stimulation (DBS). DBS had no effect on the cluster attacks, but cured an existing polydipsia as well as restlessness. However, hypothalamic DBS produced a constant, dull headache without concomitant symptoms and a high-frequent tremor. All of these effects were repeated when the stimulation was stopped and than started again. DBS had no effect on a pathological weight gain from 70 kg to 150 kg due to bulimia at night, usually during headache attacks. This case illustrates that cluster headache is, in some patients, only one symptom of a complex hypothalamic syndrome. This case also underlines that the stimulation parameters and anatomical target area for hypothalamic DBS may be too unspecific to do justice to the clinical variety of patients and concomitant symptoms. Hypothalamic DBS is an exquisite and potentially life-saving treatment method in otherwise intractable patients, but needs to be better characterised and should only be considered when other stimulation methods, such as stimulation of the greater occipital nerve, are unsuccessful.
Cav1.2 L-type Ca²⁺ channels mediate cocaine-induced GluA1 trafficking in the nucleus accumbens, a long-term adaptation dependent on ventral tegmental area Ca(v)1.3 channels.
The Journal of neuroscience : the official journal of the Society for Neuroscience, 2011

AMPA receptor (AMPAR) plasticity at glutamatergic synapses in the mesoaccumbal dopaminergic pathway has been implicated in persistent cocaine-induced behavioral responses; however, the precise mechanism underlying these changes remains unknown. Utilizing cocaine psychomotor sensitization, we have examined phosphorylation of GluA1 at key residues serine 845 (S845) and S831, as well as GluA1 cell surface levels in the nucleus accumbens (NAc) of cocaine-preexposed mice and the role of brain-specific Ca(v)1.2 and Ca(v)1.3 L-type Ca²⁺ channels (LTCCs), therein. We found higher basal levels of S845 phospho-GluA1 (P-GluA1) and cell surface GluA1 in the NAc following protracted withdrawal from cocaine exposure, changes that occur independently of LTCCs. In contrast, we found that a cocaine challenge that elicits expression of the cocaine-sensitized response increases S831 P-GluA1 that further increases surface GluA1 beyond the higher basal levels. Intra-NAc pharmacological manipulations indicate that the Ca(v)1.2-activated CaM kinase II (CaMKII) mediates cocaine-induced increase in S831 P-GluA1 and that both Ca(v)1.2-activated CaMKII and extracellular signal-regulated kinase 2 (ERK2) mediate the increase in GluA1 cell surface levels specific to the sensitized response. Experiments using adenoassociated viral vectors expressing Ca(v)1.3 and ERK2 siRNA further indicate that recruitment of the Ca(v)1.2 pathway in the NAc is dependent on ventral tegmental area Ca(v)1.3 LTCCs and ERK2. Together, these results identify candidate pathways that mediate cocaine-induced AMPAR plasticity in the NAc and provide a mechanism linking LTCCs and GluA1 plasticity to cocaine-induced persistent behavioral changes.
Noise-robust recognition of wide-field motion direction and the underlying neural mechanisms in Drosophila melanogaster.
Scientific reports, 2015

Appropriate and robust behavioral control in a noisy environment is important for the survival of most organisms. Understanding such robust behavioral control has been an attractive subject in neuroscience research. Here, we investigated the processing of wide-field motion with random dot noise at both the behavioral and neuronal level in Drosophila melanogaster. We measured the head yaw optomotor response (OMR) and the activity of motion-sensitive neurons, horizontal system (HS) cells, with in vivo whole-cell patch clamp recordings at various levels of noise intensity. We found that flies had a robust sensation of motion direction under noisy conditions, while membrane potential changes of HS cells were not correlated with behavioral responses. By applying signal classification theory to the distributions of HS cell responses, however, we found that motion direction under noise can be clearly discriminated by HS cells, and that this discrimination performance was quantitatively similar to that of OMR. Furthermore, we successfully reproduced HS cell activity in response to noisy motion stimuli with a local motion detector model including a spatial filter and threshold function. This study provides evidence for the physiological basis of noise-robust behavior in a tiny insect brain.
Reliability and Validity of the Sport Concussion Assessment Tool-3 (SCAT3) in High School and Collegiate Athletes.
The American journal of sports medicine, 2016

The Sport Concussion Assessment Tool-3 (SCAT3) facilitates sideline clinical assessments of concussed athletes. Yet, there is little published research on clinically relevant metrics for the SCAT3 as a whole.
Discontinuation and dose reduction of rituximab in relapsing-remitting multiple sclerosis.
Journal of neurology, 2021

Rituximab is safe and effective for treating relapsing-remitting multiple sclerosis (RRMS) according to phase II and observational studies. There are limited data on disease activity after discontinuation and dose reduction. The objective of this study was to evaluate the effects on inflammatory disease activity after discontinuation or dose reduction of rituximab in patients with RRMS or clinically isolated syndrome (CIS).
Quantitative relationships between huntingtin levels, polyglutamine length, inclusion body formation, and neuronal death provide novel insight into huntington's disease molecular pathogenesis.
The Journal of neuroscience : the official journal of the Society for Neuroscience, 2010

An expanded polyglutamine (polyQ) stretch in the protein huntingtin (htt) induces self-aggregation into inclusion bodies (IBs) and causes Huntington's disease (HD). Defining precise relationships between early observable variables and neuronal death at the molecular and cellular levels should improve our understanding of HD pathogenesis. Here, we used an automated microscope that tracks thousands of neurons individually over their entire lifetime to quantify interconnected relationships between early variables, such as htt levels, polyQ length, and IB formation, and neuronal death in a primary striatal model of HD. The resulting model revealed that mutant htt increases the risk of death by tonically interfering with homeostatic coping mechanisms rather than producing accumulated damage to the neuron, htt toxicity is saturable, the rate-limiting steps for inclusion body formation and death can be traced to different conformational changes in monomeric htt, and IB formation reduces the impact of the starting levels of htt of a neuron on its risk of death. Finally, the model that emerges from our quantitative measurements places critical limits on the potential mechanisms by which mutant htt might induce neurodegeneration, which should help direct future research.
Associative-memory representations emerge as shared spatial patterns of theta activity spanning the primate temporal cortex.
Nature communications, 2016

Highly localized neuronal spikes in primate temporal cortex can encode associative memory; however, whether memory formation involves area-wide reorganization of ensemble activity, which often accompanies rhythmicity, or just local microcircuit-level plasticity, remains elusive. Using high-density electrocorticography, we capture local-field potentials spanning the monkey temporal lobes, and show that the visual pair-association (PA) memory is encoded in spatial patterns of theta activity in areas TE, 36, and, partially, in the parahippocampal cortex, but not in the entorhinal cortex. The theta patterns elicited by learned paired associates are distinct between pairs, but similar within pairs. This pattern similarity, emerging through novel PA learning, allows a machine-learning decoder trained on theta patterns elicited by a particular visual item to correctly predict the identity of those elicited by its paired associate. Our results suggest that the formation and sharing of widespread cortical theta patterns via learning-induced reorganization are involved in the mechanisms of associative memory representation.
Therapeutic Potential of Transdermal Glyceryl Trinitrate in the Management of Acute Stroke.
CNS drugs, 2017

The nitric oxide donor, glyceryl trinitrate (GTN), is a candidate treatment for the management of acute stroke with haemodynamic and potential reperfusion and neuroprotective effects. When administered as a transdermal patch during the acute and subacute phases after stroke, GTN was safe, lowered blood pressure, maintained cerebral blood flow, and did not induce cerebral steal or alter functional outcome. However, when given within 6 h of stroke onset, GTN reduced death and dependency (odds ratio 0.52; 95% confidence interval 0.34-0.78), death, disability, cognitive impairment and mood disturbance, and improved quality of life (data from two trials, n = 312). In a pooled analysis of four studies (n = 186), GTN reduced between-visit systolic blood pressure variability over days 1-7 compared with no GTN (mean difference -2.09; 95% confidence interval -3.83 to -0.35; p = 0.019). The efficacy of GTN given in the ultra-acute/pre-hospital setting is currently being assessed and, if found to be beneficial, the implications for hyperacute stroke practice are significant. Here, we discuss the evidence to date, potential mechanisms of action and future possibilities, including unanswered questions, for the therapeutic potential of GTN in acute stroke.
Strain-specific programming of prenatal ethanol exposure across generations.
Alcohol (Fayetteville, N.Y.), 2017

Behavioral consequences of prenatal alcohol exposure (PAE) can be transmitted from in utero-exposed F1 generation to their F2 offspring. This type of transmission is modulated by genetic and epigenetic mechanisms. This study investigated the intergenerational consequences of prenatal exposure to a low ethanol dose (1 g/kg) during gestational days 17-20, on ethanol-induced hypnosis in adolescent male F1 and F2 generations, in two strains of rats. Adolescent Long-Evans and Sprague-Dawley male rats were tested for sensitivity to ethanol-induced hypnosis at a 3.5-g/kg or 4.5-g/kg ethanol dose using the loss of righting reflex (LORR) paradigm. We hypothesized that PAE would attenuate sensitivity to ethanol-induced hypnosis in the ethanol-exposed animals in these two strains and in both generations. Interestingly, we only found this effect in Sprague-Dawley rats. Lastly, we investigated PAE related changes in expression of GABA
Transcription Factor Motifs Associated with Anterior Insula Gene Expression Underlying Mood Disorder Phenotypes.
Molecular neurobiology, 2021

Mood disorders represent a major cause of morbidity and mortality worldwide but the brain-related molecular pathophysiology in mood disorders remains largely undefined. Because the anterior insula is reduced in volume in patients with mood disorders, RNA was extracted from the anterior insula postmortem anterior insula of mood disorder samples and compared with unaffected controls for RNA-sequencing identification of differentially expressed genes (DEGs) in (a) bipolar disorder (BD; n = 37) versus (vs.) controls (n = 33), and (b) major depressive disorder (MDD n = 30) vs. controls, and (c) low vs. high axis I comorbidity (a measure of cumulative psychiatric disease burden). Given the regulatory role of transcription factors (TFs) in gene expression via specific-DNA-binding domains (motifs), we used JASPAR TF binding database to identify TF-motifs. We found that DEGs in BD vs. controls, MDD vs. controls, and high vs. low axis I comorbidity were associated with TF-motifs that are known to regulate expression of toll-like receptor genes, cellular homeostatic-control genes, and genes involved in embryonic, cellular/organ, and brain development. Robust imaging-guided transcriptomics by using meta-analytic imaging results to guide independent postmortem dissection for RNA-sequencing was applied by targeting the gray matter volume reduction in the anterior insula in mood disorders, to guide independent postmortem identification of TF motifs regulating DEG. Our findings of TF-motifs that regulate the expression of immune, cellular homeostatic-control, and developmental genes provide novel information about the hierarchical relationship between gene regulatory networks, the TFs that control them, and proximate underlying neuroanatomical phenotypes in mood disorders.
Add on yoga treatment for negative symptoms of schizophrenia: A multi-centric, randomized controlled trial.
Schizophrenia research, 2021

The efficacy of antipsychotic medications in the treatment of negative symptoms of schizophrenia is modest at best. Preliminary studies suggest the beneficial effects of add on Yoga, a traditional Indian practice, in the treatment of schizophrenia. Hence, in this study, we examined the efficacy of yoga as an add-on treatment for negative symptoms of schizophrenia in a randomized, wait-list controlled design from two clinical institutes in south India. 89 patients (age - 34.20 ± 8.06 years; education - 14.22 ± 2.69 years; 28 females) were randomized into the add-on yoga or treatment as usual (TAU - wait-list control) group. Patients had a mean illness duration of 10.97 ± 7.24 years with an age at onset of 23.34 ± 5.81 years. Central block randomization was followed to ensure concealed allocation. Participants randomized to the yoga treatment group attended 12 supervised yoga training sessions over two weeks and practiced yoga sessions at home for the subsequent 10 weeks. 64 patients completed the trial. An intent to treat analysis was conducted with 89 participants using a linear mixed model. Improvement in negative symptoms was our primary outcome measure. The two groups were matched on demographic variables and baseline psychopathology severity. Participants in the add-on yoga group had significantly greater improvement in negative symptoms (SANS baseline: 49.13 ± 2.30; 12-weeks follow up: 31.55 ± 2.53) compared to the TAU group (SANS baseline: 51.22 ± 2.40; 12-weeks follow up: 45.30 ± 2.93; t = 3.36; p = 0.006; Cohen's d-0.65). The current study findings suggest the efficacy of yoga as an add-on treatment for negative symptoms of schizophrenia. The effectiveness of yoga practice as a regular clinical intervention for patients needs to be explored in future studies by integrating yoga services along with other clinical services.