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1.
J Parkinsons Dis ; 14(2): 269-282, 2024.
Article in English | MEDLINE | ID: mdl-38363617

ABSTRACT

Background: Additional stimulation of the substantia nigra (SNr) has been proposed to target axial symptoms and gait impairment in patients with Parkinson's disease (PD). Objective: This study aimed to characterize effects of combined deep brain stimulation (DBS) of the subthalamic nucleus (STN) and SNr on gait performance in PD and to map stimulation sites within the SNr. Methods: In a double-blinded crossover design, 10 patients with PD and gait impairment underwent clinical examination and kinematic assessment with STN DBS, combined STN+SNr DBS and OFF DBS 30 minutes after reprogramming. To confirm stimulation within the SNr, electrodes, active contacts, and stimulation volumes were modeled in a common space and overlap with atlases of SNr was computed. Results: Overlap of stimulation volumes with dorsolateral SNr was confirmed for all patients. UPDRS III, scoring of freezing during turning and transitioning, stride length, stride velocity, and range of motion of shank, knee, arm, and trunk as well as peak velocities during turning and transitions and turn duration were improved with STN DBS compared to OFF. On cohort level, no further improvement was observed with combined STN+SNr DBS but additive improvement of spatiotemporal gait parameters was observed in individual subjects. Conclusions: Combined high frequency DBS of the STN and dorsolateral SNr did not consistently result in additional short-term kinematic or clinical benefit compared to STN DBS. Stimulation intervals, frequency, and patient selection for target symptoms as well as target region within the SNr need further refinement in future trials.


Subject(s)
Deep Brain Stimulation , Parkinson Disease , Humans , Biomechanical Phenomena , Gait , Leg , Parkinson Disease/therapy , Cross-Over Studies , Double-Blind Method
2.
Nat Nanotechnol ; 18(9): 1078-1084, 2023 09.
Article in English | MEDLINE | ID: mdl-37337057

ABSTRACT

In current nanopore-based label-free single-molecule sensing technologies, stochastic processes influence the selection of translocating molecule, translocation rate and translocation velocity. As a result, single-molecule translocations are challenging to control both spatially and temporally. Here we present a method using a glass nanopore mounted on a three-dimensional nanopositioner to spatially select molecules, deterministically tethered on a glass surface, for controlled translocations. By controlling the distance between the nanopore and glass surface, we can actively select the region of interest on the molecule and scan it a controlled number of times and at a controlled velocity. Decreasing the velocity and averaging thousands of consecutive readings of the same molecule increases the signal-to-noise ratio by two orders of magnitude compared with free translocations. We demonstrate the method's versatility by assessing DNA-protein complexes, DNA rulers and DNA gaps, achieving down to single-nucleotide gap detection.


Subject(s)
Nanopores , DNA , Nanotechnology , Signal-To-Noise Ratio
3.
Addict Behav ; 143: 107683, 2023 08.
Article in English | MEDLINE | ID: mdl-36963236

ABSTRACT

The Iowa Gambling Task (IGT) is one of the most widely used paradigms for assessing decision-making. An impairment in this process may be linked to several psychopathological disorders, such as obsessive-compulsive disorder (OCD), substance abuse disorder (SUD) or attention-deficit/hyperactivity disorder (ADHD), which could make it a good candidate for being consider a transdiagnostic domain. Resting-state functional connectivity (rsFC) has been proposed as a promising biomarker of decision-making. In this study, we aimed to identify idiosyncratic decision-making profiles among healthy people and impulsive-compulsive spectrum patients during the IGT, and to investigate the role of frontoparietal network (FPN) rsFC as a possible biomarker of different decision-making patterns. Using functional near-infrared spectroscopy (fNIRS), rsFC of 114 adults (34 controls; 25 OCD; 41 SUD; 14 ADHD) was obtained. Then, they completed the IGT. Hybrid clustering methods based on individual deck choices yielded three decision-makers subgroups. Cluster 1 (n = 27) showed a long-term advantageous strategy. Cluster 2 (n = 25) presented a maladaptive decision-making strategy. Cluster 3 (n = 62) did not develop a preference for any deck during the task. Interestingly, the proportion of participants in each cluster was not different between diagnostic groups. A Bayesian general linear model showed no credible differences in the IGT performance between diagnostic groups nor credible evidence to support the role of FPN rsFC as a biomarker of decision-making under the IGT context. This study highlights the importance of exploring in depth the behavioral and neurophysiological variables that may drive decision-making in clinical and healthy populations.


Subject(s)
Gambling , Substance-Related Disorders , Adult , Humans , Decision Making/physiology , Bayes Theorem , Neuropsychological Tests , Biomarkers
4.
Brain Stimul ; 14(3): 662-675, 2021.
Article in English | MEDLINE | ID: mdl-33857664

ABSTRACT

BACKGROUND: There are still no sufficient data regarding the use of deep brain stimulation (DBS) in Gilles de la Tourette syndrome (GTS) and no agreement on optimal target. OBJECTIVE: To compare efficacy and safety of bilateral DBS of thalamus (centromedian-ventro-oral internus, CM-Voi) versus posteroventral lateral globus pallidus internus (pvl GPi)) versus sham stimulation, and baseline in severe medically refractory GTS. METHODS: In this randomized double-blind sham stimulation-controlled trial (RCT), 10 patients (3 women, mean age = 29.4 ± 10.2 SD, range 18-47) underwent three blinded periods each lasting three months including (i) sham, (ii) pvl GPi (on-GPi), and (iii) thalamic stimulation (on-thal) followed by an open uncontrolled long-term follow-up (up to 9 years) with individually determined target and stimulation settings. RESULTS: Nine patients completed the RCT. At group level, on-GPi - but not on-thal - resulted in a significant tic reduction compared to baseline, but had no effect on premonitory urges and psychiatric comorbidities. Direct comparisons of targets resulted in inconsistent or negative (compared to sham) findings. During follow-up, we found no improvement of tics, comorbidities, and quality of life at group level, however, single patients benefitted continuously from thalamic DBS. At last follow-up 89.9 months (mean) after surgery, 50% of patients had discontinued DBS. Hardware infections occurred in 3/10 patients. CONCLUSION: Our data suggest that the initial effect of pvl GPi DBS is superior to thalamic (CM-Voi) DBS. While half of the patients discontinued treatment, single patients benefitted from thalamic DBS even after years. It is likely that outcome is influenced by various factors beyond the mere change in tic severity.


Subject(s)
Deep Brain Stimulation , Tourette Syndrome , Child, Preschool , Female , Globus Pallidus , Humans , Infant , Quality of Life , Thalamus , Tourette Syndrome/therapy , Treatment Outcome
5.
AJNR Am J Neuroradiol ; 42(3): 487-492, 2021 03.
Article in English | MEDLINE | ID: mdl-33446501

ABSTRACT

BACKGROUND AND PURPOSE: Transradial access for neurointerventional procedures has been proved a safer and more comfortable alternative to femoral artery access. We present our experience with transradial (distal radial/anatomic snuffbox and radial artery) access for treatment of intracranial aneurysms using all 3 FDA-approved flow diverters. MATERIALS AND METHODS: This was a high-volume, dual-center, retrospective analysis of each institution's data base between June 2018 and June 2020 and a collection of all patients treated with flow diversion via transradial access. Patient demographic information and procedural and radiographic data were obtained. RESULTS: Seventy-four patients were identified (64 female patients) with a mean age of 57.5 years with a total of 86 aneurysms. Most aneurysms were located in the anterior circulation (93%) and within the intracranial ICA (67.4%). The mean aneurysm size was 5.5 mm. Flow diverters placed included the Pipeline Embolization Device (Flex) (PED, n = 65), the Surpass Streamline Flow Diverter (n = 8), and the Flow-Redirection Endoluminal Device (FRED, n = 1). Transradial access was successful in all cases, but femoral crossover was required in 3 cases (4.1%) due to tortuous anatomy and inadequate support of the catheters in 2 cases and an inability to navigate to the target vessel in a patient with an aberrant right subclavian artery. All 71 other interventions were successfully performed via the transradial approach (95.9%). No access site complications were encountered. Asymptomatic radial artery occlusion was encountered in 1 case (3.7%). CONCLUSIONS: Flow diverters can be successfully placed via the transradial approach with high technical success, low access site complications, and a low femoral crossover rate.


Subject(s)
Embolization, Therapeutic/methods , Endovascular Procedures/methods , Intracranial Aneurysm/therapy , Radial Artery/surgery , Aged , Blood Vessel Prosthesis , Catheters , Female , Humans , Male , Middle Aged , Retrospective Studies , Treatment Outcome
6.
J Dent Res ; 100(5): 549-556, 2021 05.
Article in English | MEDLINE | ID: mdl-33419383

ABSTRACT

Genome-wide transcriptomic analyses in whole tissues reflect the aggregate gene expression in heterogeneous cell populations comprising resident and migratory cells, and they are unable to identify cell type-specific information. We used a computational method (population-specific expression analysis [PSEA]) to decompose gene expression in gingival tissues into cell type-specific signatures for 8 cell types (epithelial cells, fibroblasts, endothelial cells, neutrophils, monocytes/macrophages, plasma cells, T cells, and B cells). We used a gene expression data set generated using microarrays from 120 persons (310 tissue samples; 241 periodontitis affected and 69 healthy). Decomposition of the whole-tissue transcriptomes identified differentially expressed genes in each of the cell types, which mapped to biologically relevant pathways, including dysregulation of Th17 cell differentiation, AGE-RAGE signaling, and epithelial-mesenchymal transition in epithelial cells. We validated selected PSEA-predicted, differentially expressed genes in purified gingival epithelial cells and B cells from an unrelated cohort (n = 15 persons), each of whom contributed with 1 periodontitis-affected and 1 healthy gingival tissue sample. Differential expression of these genes by quantitative reverse transcription polymerase chain reaction corroborated the PSEA predictions and pointed to dysregulation of biologically important pathways in periodontitis. Collectively, our results demonstrate the robustness of the PSEA in the decomposition of gingival tissue transcriptomes and its ability to identify differentially regulated transcripts in particular cellular constituents. These genes may serve as candidates for further investigation with respect to their roles in the pathogenesis of periodontitis.


Subject(s)
Periodontitis , Transcriptome , Endothelial Cells , Gene Expression Profiling , Gingiva , Humans , Periodontitis/genetics , Transcriptome/genetics
7.
Eur J Neurol ; 27(10): 1937-1947, 2020 10.
Article in English | MEDLINE | ID: mdl-32416613

ABSTRACT

BACKGROUND AND PURPOSE: Post-hypoxic movement disorders and chronic post-hypoxic myoclonus are rare complications after cardiac arrest in adults. Our study investigates the clinical spectrum, neuroimaging results, therapy and prognosis of these debilitating post-hypoxic sequelae. METHODS: This retrospective study included 72 patients from the neurological intensive care unit at a university hospital, who were diagnosed with hypoxic-ischaemic encephalopathy after cardiac arrest between January 2007 and September 2018. Clinical records were screened for occurrence of post-hypoxic movement disorders and chronic post-hypoxic myoclonus. Affected patients were further analysed for applied neuroprognostic tests, administered therapy and treatment response, and the outcome of these movement disorders and neurological function. RESULTS: Nineteen out of 72 screened patients exhibited post-hypoxic motor symptoms. Basal ganglia injury was the most likely neuroanatomical correlate of movement disorders as indicated by T1 hyperintensities and hypometabolism of this region in magnetic resonance imaging and positron emission tomography computed tomography. Levomepromazine and intrathecal baclofen showed first promising and mostly prompt responses to control these post-hypoxic movement disorders and even hyperkinetic storms. In contrast, chronic post-hypoxic myoclonus best responded to co-application of clonazepam, levetiracetam and primidone. Remission rates of post-hypoxic movement disorders and chronic post-hypoxic myoclonus were 58% and 50%, respectively. Affected patients seemed to present a rather good recovery of cognitive functions in contrast to the often more severe physical deficits. CONCLUSIONS: Post-hypoxic movement disorders associated with pronounced basal ganglia dysfunction might be efficiently controlled by levomepromazine or intrathecal baclofen. Their occurrence might be an indicator for a more unfavourable, but often not devastating, neurological outcome.


Subject(s)
Brain Injuries , Heart Arrest , Movement Disorders , Myoclonus , Adult , Heart Arrest/complications , Humans , Movement Disorders/diagnostic imaging , Movement Disorders/etiology , Myoclonus/diagnostic imaging , Myoclonus/drug therapy , Myoclonus/etiology , Retrospective Studies
8.
Eur Cell Mater ; 39: 171-182, 2020 04 17.
Article in English | MEDLINE | ID: mdl-32301500

ABSTRACT

Infections are often caused by pathobionts, endogenous bacteria that belong to the microbiota. Trauma and surgical intervention can allow bacteria to overcome host defences, ultimately leading to sepsis if left untreated. One of the main defence strategies of the immune system is the production of highly specific antibodies. In the present proof-of-concept study, plasma antibodies against 9 major pathogens were measured in sepsis patients, as an example of severe systemic infections. The binding of plasma antibodies to bacterial extracellular proteins was quantified using a semi-automated immunoblot assay. Comparison of the pathogen-specific antibody levels before and after infection showed an increase in plasma IgG in 20 out of 37 tested patients. This host-directed approach extended the results of pathogen-oriented microbiological and PCR diagnostics: a specific antibody response to additional bacteria was frequently observed, indicating unrecognised poly-microbial invasion. This might explain some cases of failed, seemingly targeted antibiotic treatment.


Subject(s)
Antibodies/immunology , Sepsis/immunology , Sepsis/microbiology , Adult , Aged , Aged, 80 and over , Antibody Formation/immunology , Case-Control Studies , Humans , Immunoglobulin G/blood , Kinetics , Middle Aged , Sepsis/blood , Species Specificity
9.
Behav Brain Res ; 382: 112485, 2020 03 16.
Article in English | MEDLINE | ID: mdl-31958518

ABSTRACT

Behavioral and anatomical sex-related differences have been traditionally found in decision-making processes assessed by Iowa Gambling Task (IGT). So far, the administration of transcranial direct current stimulation (tDCS) over orbitofrontal regions has shown an enhancing effect over decision-making. However, it is unknown whether there is a sex-dependent effect of stimulation in decision-making, a key question considering previous differences between men and women in IGT and the influence of individual differences in tDCS. The present study examines, at first time, the interaction between sex and tDCS in decision-making. For that aim, in a first experimental phase, ninety-two healthy participants performed the IGT. In a second phase, sixty-one participants received 20 min of anodal or sham tDCS over the right orbitofrontal cortex (rOFC) in a single-session pre-post sham-controlled study. To support the focality of the montage, a Stop Signal Task (SST) was used as a control task and also a numerical simulation of current flow distribution was performed. According to literature, in the first phase, results showed that men outperformed women in the IGT. In the second phase, the stimulation varied the IGT performance according to a sex specific manner: anodal tDCS increased the IGT performance in women, while in men; the stimulation did not produce any effect. Results were mediated by sex-specific morphological differences. These results highlight the necessity to consider the interaction of sex with the effect of the stimulation in future tDCS protocols, specifically in future clinical studies.


Subject(s)
Decision Making/physiology , Prefrontal Cortex/physiology , Risk-Taking , Sex Characteristics , Adult , Animals , Female , Gambling , Humans , Male , Models, Neurological , Neuropsychological Tests , Transcranial Direct Current Stimulation , Young Adult
10.
AJNR Am J Neuroradiol ; 41(1): 115-121, 2020 01.
Article in English | MEDLINE | ID: mdl-31924604

ABSTRACT

BACKGROUND AND PURPOSE: Unilateral decreased/nonvisualization of a transverse dural sinus on MRV poses a diagnostic dilemma when gadolinium administration is contraindicated. We determined the frequency of unilateral decreased/nonvisualization of the transverse dural sinus and the performance of pregadolinium MR imaging sequences in diagnosing transverse sinus thrombosis in the presence of unilateral decreased/nonvisualization on phase-contrast MRV. MATERIALS AND METHODS: We conducted a retrospective review of consecutive 3D phase-contrast MRV (VENC, 30 cm/s) and routine brain imaging (noncontrast sagittal T1, axial T2, FLAIR, DWI, GRE, and postgadolinium 3D-MPRAGE images) performed during a 3-year period for a total of 208 patients. Nonvisualization of a transverse dural sinus was defined as ≥50% nonvisualization of the transverse sinus caliber versus the contralateral side on MRV. Noncontrast imaging findings were considered abnormal when hyperintense signal was present on T2, FLAIR, T1, and DWI, and there were T2* blooming artifacts on GRE and DWI. Postgadolinium 3D-MPRAGE was used to confirm the diagnosis of transverse sinus thrombosis. RESULTS: Nonvisualization of a transverse dural sinus was observed in 72/208 (34.6%) patients on MRV; 56/72 (77.8%) were without transverse sinus thrombosis, and 16/72 (22.2%) patients had transverse dural sinus thrombosis. Nonvisualization of a transverse dural sinus was seen in 56/192 (29.2%) patients without transverse sinus thrombosis and 16/16 (100%) with transverse sinus thrombosis. Abnormal findings on DWI (transverse sinus hyperintense signal or T2* blooming artifact) are 93.8% sensitive and 100.0% specific for transverse sinus thrombosis. Other noncontrast MR imaging sequences ranged from 56.3%-68.8% sensitive and 91.1%-100.0% specific. CONCLUSIONS: Nonvisualization of a transverse dural sinus is a frequent phenomenon on phase-contrast MRV. DWI can be effectively used to exclude sinus thrombosis when nonvisualization of a transverse dural sinus is a diagnostic conundrum on phase-contrast MRV and contrast-enhanced studies are contraindicated.


Subject(s)
Image Interpretation, Computer-Assisted/methods , Lateral Sinus Thrombosis/diagnostic imaging , Magnetic Resonance Imaging/methods , Neuroimaging/methods , Transverse Sinuses/diagnostic imaging , Adolescent , Adult , Aged , Aged, 80 and over , Contrast Media , Female , Gadolinium , Humans , Imaging, Three-Dimensional/methods , Male , Middle Aged , Retrospective Studies , Young Adult
12.
Urologe A ; 58(11): 1313-1323, 2019 Nov.
Article in German | MEDLINE | ID: mdl-31659368

ABSTRACT

In this review article, the authors describe all relevant aspects of the new S2k guideline from the German Society of Urology (Deutschen Gesellschaft für Urologie, DGU) for the diagnosis and treatment of IC/PBS (interstitial cystitis/painful bladder syndrome). A list of necessary and optional examinations and the necessity of diagnosis of exclusion are summarized and evaluated. The treatment options listed (ranging from conservative, oral drug, and complementary medicine to interventional surgical procedures) also give the reader a good overview of the contents of the guideline and possible therapeutic approaches. Finally, the recommendations including consensus of the guideline group are also summarized in various information boxes.


Subject(s)
Cystitis, Interstitial/diagnosis , Cystitis, Interstitial/therapy , Practice Guidelines as Topic , Urology/standards , Germany , Humans , Pain , Physical Examination , Societies, Medical
13.
Article in English | MEDLINE | ID: mdl-30940483

ABSTRACT

Schedule-induced polydipsia (SIP), characterized by the development of persistent and excessive drinking under intermittent food-reinforcement schedules, is an animal model of compulsive behavior that can differentiate two populations: high drinkers (HD) and low drinkers (LD). The aim of the present study was to identify behavioral and biological markers to predict the vulnerability to developing compulsive-like drinking in SIP. Adult male Wistar rats were first trained in a spatial-discrimination serial reversal-learning task and in a reinforcer devaluation task to measure behavioral flexibility and habit formation, respectively. Subsequently, the rats were tested using the SIP protocol and identified as HD or LD based on their drinking rates. The performance of HD and LD rats in the two previous tasks was then analyzed. Before and after SIP exposure, blood glucose and plasma corticosterone (CORT) levels were measured. Additionally, serum electrolyte levels, including sodium, potassium, and chloride, were analyzed after SIP. HD rats showed higher behavioral inflexibility by exhibiting increased perseverative responses in the reversal-learning task and insensitivity to reinforcer devaluation during extinction under selective satiation. After SIP exposure, HD rats exhibited increased basal plasma CORT levels, indicating that this vulnerable group might have a dysregulation of the HPA axis. Although HD and LD rats had blood glucose levels within normal range, the HD group showed lower levels. The HD group did not exhibit hyponatremia (i.e., reduced serum sodium levels) when compared to LD rats after 20 daily SIP sessions. The results of the present study demonstrated that HD rats exhibit behavioral inflexibility and greater habitual-like behavior before SIP. Moreover, these results highlight the importance of measuring different behavioral and biological markers for predicting the vulnerability to developing compulsivity, and for enhancing the understanding of the pathophysiology of compulsive spectrum disorders.


Subject(s)
Compulsive Behavior/psychology , Drinking Behavior , Polydipsia/psychology , Reinforcement, Psychology , Animals , Biomarkers , Blood Glucose/analysis , Compulsive Behavior/physiopathology , Conditioning, Operant , Corticosterone/blood , Disease Models, Animal , Drinking Behavior/physiology , Male , Polydipsia/physiopathology , Rats , Rats, Wistar , Reversal Learning
14.
Brain Stimul ; 12(5): 1111-1120, 2019.
Article in English | MEDLINE | ID: mdl-31031208

ABSTRACT

BACKGROUND: Data on pediatric DBS is still limited because of small numbers in single center series and lack of systematic multi-center trials. OBJECTIVES: We evaluate short- and long-term adverse events (AEs) of patients undergoing deep brain stimulation (DBS) during childhood and adolescence. METHODS: Data collected by the German registry on pediatric DBS (GEPESTIM) were analyzed according to reversible and irreversible AEs and time of occurrence with relation to DBS-surgery: Intraoperative, perioperative (<4 weeks), postoperative (4 weeks < 6 months) and long term AEs (>6 months). RESULTS: 72 patients with childhood-onset dystonia from 10 DBS-centers, who received 173 DBS electrodes and 141 implantable pulse generators (IPG), were included in the registry. Mean time of postoperative follow-up was 4.6 ±â€¯4 years. In total, 184 AEs were documented in 53 patients (73.6%). 52 DBS-related AEs in 26 patients (36.1%) required 45 subsequent surgical interventions 4.7 ±â€¯4.1 years (range 3 months-15 years) after initial implantation. The total risk of an AE requiring surgical intervention was 7.9% per electrode-year. Hardware-related AEs were the most common reason for surgery. There was a tendency of a higher rate of AEs in patients aged 7-9 years beyond 6 months after implantation. DISCUSSION: The intraoperative risk of AEs in pediatric patients with dystonia undergoing DBS is very low, whereas the rate of postoperative hardware-related AEs is a prominent feature with a higher occurrence compared to adults, especially on long-term follow-up. CONCLUSION: Factors leading to such AEs must be identified and patient management has to be focused on risk minimization strategies in order to improve DBS therapy and maximize outcome in pediatric patients.


Subject(s)
Deep Brain Stimulation/adverse effects , Dystonic Disorders/epidemiology , Dystonic Disorders/therapy , Electrodes, Implanted/adverse effects , Adolescent , Child , Dystonic Disorders/diagnosis , Female , Follow-Up Studies , Germany/epidemiology , Humans , Male , Surgical Wound Infection/diagnosis , Surgical Wound Infection/epidemiology
16.
Faraday Discuss ; 205: 537-545, 2017 12 04.
Article in English | MEDLINE | ID: mdl-28879365

ABSTRACT

We study the optical response of individual nm-wide plasmonic nanocavities using a nanoparticle-on-mirror design utilised as an electrode in an electrochemical cell. In this geometry Au nanoparticles are separated from a bulk Au film by an ultrathin molecular spacer, giving intense and stable Raman amplification of 100 molecules. Modulation of the plasmonic spectra and the SERS response is observed with an applied voltage under a variety of electrolytes. Different scenarios are discussed to untangle the various mechanisms that can be involved in the electronic interaction between NPs and electrode surfaces.

17.
Nano Lett ; 17(8): 4840-4845, 2017 08 09.
Article in English | MEDLINE | ID: mdl-28686457

ABSTRACT

We study in real time the optical response of individual plasmonic nanoparticles on a mirror, utilized as electrodes in an electrochemical cell when a voltage is applied. In this geometry, Au nanoparticles are separated from a bulk Au film by an ultrathin molecular spacer. The nanoscale plasmonic hotspot underneath the nanoparticles locally reveals the modified charge on the Au surface and changes in the polarizability of the molecular spacer. Dark-field and Raman spectroscopy performed on the same nanoparticle show our ability to exploit isolated plasmonic junctions to track the dynamics of nanoelectrochemistry. Enhancements in Raman emission and blue-shifts at a negative potential show the ability to shift electrons within the gap molecules.

18.
Heredity (Edinb) ; 119(4): 207-213, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28635968

ABSTRACT

Reproduction and dispersal are key aspects of species life history that influence spatial genetic structure in populations. Several ant species in the genus Cataglyphis have evolved a unique breeding system in which new reproductives (that is, queens and males) are produced asexually by parthenogenesis; in contrast, non-reproductives (that is, workers) are produced via sexual reproduction by mates from distinct genetic lineages. We investigated how these two coexisting reproductive methods affect population-level spatial genetic structure using the ant Cataglyphis mauritanica as a model. We obtained genotypes for queens and their male mates from 338 colonies, and we found that the two lineages present in the study population occurred with equal frequency. Furthermore, analysis of spatial genetic structure revealed strong sex-biased dispersal. Because queens were produced by parthenogenesis and because they dispersed over short distances, there was an extreme level of spatial structuring: a mosaic of patches composed of clonal queens was formed. Males, on the other hand, dispersed over several hundred metres and, thus, across patches, ensuring successful interlineage mating.


Subject(s)
Animal Distribution/physiology , Ants/physiology , Animals , Ants/genetics , Female , Genotype , Male , Parthenogenesis , Reproduction/physiology
20.
Clin Neurophysiol ; 128(4): 538-548, 2017 04.
Article in English | MEDLINE | ID: mdl-28226288

ABSTRACT

OBJECTIVE: Neural interactions between cortex and basal ganglia are pivotal for sensorimotor processing. Specifically, coherency between cortex and subthalamic structures is a frequently studied phenomenon in patients with Parkinson's disease. However, it is unknown whether cortico-subthalamic coherency might also relate to cognitive aspects of task performance, e.g., language processing. Furthermore, standard coherency studies are challenged by how to efficiently handle multi-channel recordings. METHODS: In eight patients with Parkinson's disease treated with deep brain stimulation, simultaneous recordings of surface electroencephalography and deep local field potentials were obtained from bilateral subthalamic nuclei, during performing a lexical decision task. A recent multivariate coherency measure (maximized imaginary part of coherency, MIC) was applied, simultaneously accounting for multi-channel recordings. RESULTS: Cortico-subthalamic synchronization (MIC) in 14-35Hz oscillations positively correlated with accuracy in lexical decisions across patients, but not in 7-13Hz oscillations. In contrast to multivariate MIC, no significant correlation was obtained when extracting cortico-subthalamic synchronization by "standard" bivariate coherency. CONCLUSIONS: Cortico-subthalamic synchronization may relate to non-motor aspects of task performance, here reflected in lexical accuracy. SIGNIFICANCE: The results tentatively suggest the relevance of cortico-subthalamic interactions for lexical decisions. Multivariate coherency might be effective to extract neural synchronization from multi-channel recordings.


Subject(s)
Cortical Synchronization , Decision Making , Language , Parkinson Disease/physiopathology , Adult , Aged , Basal Ganglia/physiopathology , Case-Control Studies , Cerebral Cortex/physiopathology , Deep Brain Stimulation , Female , Humans , Male , Middle Aged
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