Dissociation of impulsive traits by subthalamic metabotropic glutamate receptor 4

Behavioral strategies require gating of premature responses to optimize outcomes. Several brain areas control impulsive actions, but the neuronal basis of natural variation in impulsivity between individuals remain largely unknown. Here, by combining a Go/No-Go behavioral assay with resting state (rs) functional MRI in mice, we identified the subthalamic nucleus (STN), a known gate for motor control in the basal ganglia, as a major hot spot for trait impulsivity. In vivo recorded STN neural activity encoded impulsive action as a separable state from basic motor control, characterized by decoupled STN/Substantia nigra pars reticulata (SNr) mesoscale networks. Optogenetic modulation of STN activity bi-directionally controlled impulsive behavior. Pharmacological and genetic manipulations showed that these impulsive actions are modulated by metabotropic glutamate receptor 4 (mGlu4) function in STN and its coupling to SNr in a behavioral trait-dependent manner, and independently of general motor function. In conclusion, STN circuitry multiplexes motor control and trait impulsivity, which are molecularly dissociated by mGlu4. This provides a potential mechanism for the genetic modulation of impulsive behavior, a clinically relevant predictor for developing psychiatric disorders associated with impulsivity.

Suicidal Ideation Among Adolescents—The Role of Sexual Abuse, Depression, and Impulsive Behavior

Suicide is the second leading cause of death among adolescents. With every fifth Indian to be an adolescent, the cost of an adolescent dying by suicide is enormous. This necessitates an understanding of the potential risk factors of suicidal ideation among adolescents. Secondary data analysis is performed on cross-sectional survey data obtained from Understanding the Lives of Adolescents and Young Adults. The survey was conducted in two Indian states of Bihar and Uttar Pradesh. Descriptive statistics, bivariate analysis and logistic regression are done to examine the results. Adolescent girls reported more suicidal ideation than boys. The odds of suicidal ideation are significantly higher among adolescents whose mother faced physical abuse and adolescents who themselves experienced sexual abuse. Adolescent boys and girls who have moderate depressive symptoms and impulsive behavior are significantly more likely to report suicidal ideation. The results help in identifying the adolescents who are at a particular risk for suicidal ideation while planning for intervention program for prevention of suicide.

Divergence-Based Segmentation Algorithm for Heavy-Tailed Acoustic Signals with Time-Varying Characteristics

Many real-world systems change their parameters during the operation. Thus, before the analysis of the data, there is a need to divide the raw signal into parts that can be considered as homogeneous segments. In this paper, we propose a segmentation procedure that can be applied for the signal with time-varying characteristics. Moreover, we assume that the examined signal exhibits impulsive behavior, thus it corresponds to the so-called heavy-tailed class of distributions. Due to the specific behavior of the data, classical algorithms known from the literature cannot be used directly in the segmentation procedure. In the considered case, the transition between parts corresponding to homogeneous segments is smooth and non-linear. This causes that the segmentation algorithm is more complex than in the classical case. We propose to apply the divergence measures that are based on the distance between the probability density functions for the two examined distributions. The novel segmentation algorithm is applied to real acoustic signals acquired during coffee grinding. Justification of the methodology has been performed experimentally and using Monte-Carlo simulations for data from the model with heavy-tailed distribution (here the stable distribution) with time-varying parameters. Although the methodology is demonstrated for a specific case, it can be extended to any process with time-changing characteristics.

CLINICAL MANIFESTATIONS OF ANTI-NMDA RECEPTOR ENCEPHALITIS IN CHILDREN

The aim of the study was to determine the clinical features of anti-NMDAR encephalitis in children. Materials and methods of research: 11 patients were selected from the group of children with autoimmune encephalitis, who met the diagnostic criteria for reliable anti-NMDAR encephalitis. A retro-prospective analysis of clinical symptoms, laboratory, neurophysiological and neuroimaging data, treatment, duration of primary hospitalization and long-term results of treatment was carried out, neuropsychological testing of patients was performed in the follow-up. Results: the age of the patients was 8.5±4.4 years, the gender composition of boys/girls was 1/10 (9.1%/90.9%). The average follow-up period was 17±12 months. In 73% of cases, there was an acute onset of the disease without a prodromal phase and with rapidly growing signs of neurological dysfunction: behavior change (11/100%), epileptic seizures (11/100%), speech impairment (10/90.9%), movement disorders (10/90.9%), disturbed sleep/wakefulness rhythm (9/81.8%), hallucinations (5/45.5%), autonomic disorders (6/54.5%), sensory disturbance (1/9,1%). In 82% of cases, therapy was required in the intensive care unit. When analyzing EEG monitoring in children, the extreme delta brush pattern was revealed in only one patient. Neuroimaging revealed no specific changes in the substance of the brain. The paraneoplastic nature of the disease could not be established in any case. 4 patients (36.36%) had relapses of the disease after 1.5–27 months. from the onset of the disease. All children showed a favorable outcome without a gross neurological deficit, but complaints of increased fatigue, headaches, poor memory, a decrease in vocabulary, and impulsive behavior persisted.

Adaptation and validation of a German version of the Dickman impulsivity inventory for the assessment of functional and dysfunctional impulsivity

Impulsive behavior tends to have a negative connotation in the sense that it is usually associated with detrimental or dysfunctional outcomes. However, under certain circumstances, impulsive behaviors may also have beneficial or functional outcomes. Dickman’s Impulsivity Inventory (DII) measures these two distinct aspects of impulsivity, namely, dysfunctional impulsivity (the tendency to act with less forethought than do most people which leads to difficulties) and functional impulsivity (the tendency to act with little forethought when the situation is optimal). In the present study, we translated the DII into German and validated the German version in a sample of 543 adults. The original 23-item model was considered unsuitable for the German version as suggested by fit indices of a confirmatory factor analysis. Exploratory factor analyses rather supported a 16-item version. Further psychometric analyses and inferential statistical analyses on the final German DII indicated its appropriateness for use in German-speaking populations and support a two-factor solution of the DII. Finally, exploratory analyses on the German DII suggest differential relationships between dysfunctional and functional impulsivity and self-reported lifestyle-related variables (smoking, alcohol usage, and sports behavior).