Bilateral Representation of Sensorimotor Responses in Benign Adult Familial Myoclonus Epilepsy: An MEG Study

Patients with cortical reflex myoclonus manifest typical neurophysiologic characteristics due to primary sensorimotor cortex (S1/M1) hyperexcitability, namely, contralateral giant somatosensory-evoked potentials/fields and a C-reflex (CR) in the stimulated arm. Some patients show a CR in both arms in response to unilateral stimulation, with about 10-ms delay in the non-stimulated compared with the stimulated arm. This bilateral C-reflex (BCR) may reflect strong involvement of bilateral S1/M1. However, the significance and exact pathophysiology of BCR within 50 ms are yet to be established because it is difficult to identify a true ipsilateral response in the presence of the giant component in the contralateral hemisphere. We hypothesized that in patients with BCR, bilateral S1/M1 activity will be detected using MEG source localization and interhemispheric connectivity will be stronger than in healthy controls (HCs) between S1/M1 cortices. We recruited five patients with cortical reflex myoclonus with BCR and 15 HCs. All patients had benign adult familial myoclonus epilepsy. The median nerve was electrically stimulated unilaterally. Ipsilateral activity was investigated in functional regions of interest that were determined by the N20m response to contralateral stimulation. Functional connectivity was investigated using weighted phase-lag index (wPLI) in the time-frequency window of 30–50 ms and 30–100 Hz. Among seven of the 10 arms of the patients who showed BCR, the average onset-to-onset delay between the stimulated and the non-stimulated arm was 8.4 ms. Ipsilateral S1/M1 activity was prominent in patients. The average time difference between bilateral cortical activities was 9.4 ms. The average wPLI was significantly higher in the patients compared with HCs in specific cortico-cortical connections. These connections included precentral-precentral, postcentral-precentral, inferior parietal (IP)-precentral, and IP-postcentral cortices interhemispherically (contralateral region-ipsilateral region), and precentral-IP and postcentral-IP intrahemispherically (contralateral region-contralateral region). The ipsilateral response in patients with BCR may be a pathologically enhanced motor response homologous to the giant component, which was too weak to be reliably detected in HCs. Bilateral representation of sensorimotor responses is associated with disinhibition of the transcallosal inhibitory pathway within homologous motor cortices, which is mediated by the IP. IP may play a role in suppressing the inappropriate movements seen in cortical myoclonus.

A concert for babies: Attentional, affective, and motor responses in an infant audience

Many of our most powerful musical experiences are shared with others, and researchers have increasingly investigated responses to music in group contexts. Though musical performances for infants are growing in popularity, most research on infants’ responses to live music has focused on solitary caregiver-infant pairs. Here, we report infants’ attentional, affective, and sensorimotor responses to live music as audience members. Two groups of caregiver-infant (6-18 months) pairs (50 total) watched a short musical performance with two song styles – lullaby and playsong. Caregivers were instructed to watch passively or interactively. The playsong captured more attention and, especially in the interactive condition, elicited more smiles. Notably, infant attention synchronized more with their own caregiver than a random caregiver. Infants with enriched musical home environments spent more time moving rhythmically (“dancing”). Overall, infants’ responses to live musical performance in an audience were influenced by song style, caregiver behavior, and their own musical histories.

Stability of sensorimotor responses of cadets of higher education institutions with specific training conditions that train police officers

The ability to maintain high speed and accuracy of sensorimotor reactions for a long time under the influence of various interfering factors is an important component in the training structure of future law enforcement officers. Improving of the sensorimotor reactions of higher education students in institutions that train police officers takes place in the process of the discipline "Special Physical Training". Methods of general physical training (sports games, competitive methods), as well as, methods of simulating service situations (attempt of the offender to get the weapon, group interaction of police, protection from the threat of weapons, protection from blows with hands and feet) are used to achieve this purpose. We conducted a study of the complex reaction of choice of cadets in the normal conditions and under the influence of interfering factors. The results show that male cadets and some women as a result of two years training significantly improve the resistance of sensorimotor responses to interfering factors (the speed of a complex reaction of choice without interference, with interference, the total number of errors). The results show that the traditional curriculum of the discipline "Special Physical Training" in higher education institutions with specific training conditions, which provide training of police officers, effectively helps to improve the stability of sensorimotor responses of cadets. Improving the efficiency of the training process in the direction of increasing the stability of sensorimotor responses of female cadets requires special attention.

ASSESSMENT OF THE FUNCTIONAL STATE OF THE CENTRAL NERVOUS SYSTEM IN ADOLESCENTS LIVING IN THE NORTH

Background. The function of the central nervous system in adolescents reflects the complex influence of climatic and social conditions, as well as morphofunctional lability characteristic of puberty. Studying the functional state of the central nervous system in adolescents living at high latitudes is important for forming a region-dependent norm of the functional state of the body. Aim. The paper aims to reveal the features of sensorimotor integration as an indicator of the functional state of the central nervous system in 11–14-year-old students living in the North. Materials and methods. 88 schoolchildren from Surgut (46 males and 42 females) aged 11–12 years (1 group, n = 33) and 13–14 years (2 group, n = 55) were examined. Psychophysiological testing was carried out with the help of the NS-Psychotest hardware and software (Neurosoft, Ivanovo). The following methods were used: simple visual and motor reaction, complex visual and motor reaction – choice reaction. Mathematical and statistical processing was carried out in Microsoft Excel and Statistica 10.0. Results. Sex-related differences in neurodynamic data were revealed: average parameters of boys of both groups in comparison with girls are characteristic of a more active and mobile central nervous system. The functional state of the central nervous system in males is higher than that of females in both age groups, though, sensorimotor responses of females are more stable. Age-related improvements in sensorimotor integration were noted due to improved cerebral processing of sensory information by reducing latency time of sensorimotor responses. In males, depending on age, there was a tendency to negative changes in the functional state of the central nervous system. Conclusions. The results obtained describe the average level of activation and a high level of functional mobility of nervous processes in all adolescents. The average level of the functional state of the central nervous system reflects the optimal functional capabilities of the participants, which is the basis for effective psychophysiological adaptation to living conditions and educational activities.

Multiple nerve rings coordinate Hydra mechanosensory behavior

Hydra vulgaris is an emerging model organism for neuroscience due to its small size, transparency, genetic tractability, and regenerative nervous system; however, fundamental properties of its sensorimotor behaviors remain unknown. Here, we use microfluidic devices combined with fluorescent calcium imaging and surgical resectioning to study how the nervous system coordinates Hydra’s mechanosensory response. We find that mechanical stimuli cause animals to contract, and this response relies on both the oral and aboral nerve rings. We also find that these nerve rings work together to coordinate spontaneous contractions suggesting that spontaneous behavior and sensorimotor responses converge on to a common neural circuit. These findings improve our understanding of how Hydra’s diffuse nervous system supports sensorimotor behaviors, which is needed to increase the utility of Hydra as a model organism for neuroscience.

Acute DOB and PMA Administration Impairs Motor and Sensorimotor Responses in Mice and Causes Hallucinogenic Effects in Adult Zebrafish

The drastic increase in hallucinogenic compounds in illicit drug markets of new psychoactive substances (NPS) is a worldwide threat. Among these, 2, 5-dimetoxy-4-bromo-amphetamine (DOB) and paramethoxyamphetamine (PMA; marketed as “ecstasy”) are frequently purchased on the dark web and consumed for recreational purposes during rave/dance parties. In fact, these two substances seem to induce the same effects as MDMA, which could be due to their structural similarities. According to users, DOB and PMA share the same euphoric effects: increasing of the mental state, increasing sociability and empathy. Users also experienced loss of memory, temporal distortion, and paranoia following the repetition of the same thought. The aim of this study was to investigate the effect of the acute systemic administration of DOB and PMA (0.01–30 mg/kg; i.p.) on motor, sensorimotor (visual, acoustic, and tactile), and startle/PPI responses in CD-1 male mice. Moreover, the pro-psychedelic effect of DOB (0.075–2 mg/kg) and PMA (0.0005–0.5 mg/kg) was investigated by using zebrafish as a model. DOB and PMA administration affected spontaneous locomotion and impaired behaviors and startle/PPI responses in mice. In addition, the two compounds promoted hallucinatory states in zebrafish by reducing the hallucinatory score and swimming activity in hallucinogen-like states.

Flèche versus Lunge as the Optimal Footwork Technique in Fencing

The objective of the study reported in this paper involved identifying the fencing attack (flèche versus lunge) that provides greater effectiveness in a real competition. Two hypotheses are presented in the study. The first hypothesis involves the greater effectiveness of the flèche with regard to bioelectric muscular tension, and the second hypothesis involves the reduction of movement time of the flèche. Therefore, analyses were conducted by the application of EMG (electromyography) signal, ground reaction forces, and parameters representing sensorimotor responses (RT—reaction time and MT—movement time). This study included six world-leading female épée fencers (mean age: 24.6 ± 6.2 years). Throughout the procedure, the subjects performed flèche and lunge touches at the command of the coach based on visual stimuli. The experimental results indicated the greater effectiveness of the flèche compared with the lunge with regard to increases in EMG values (p = 0.027) in the lateral and medial gastrocnemius muscles and decreases in the duration of the movement phase (p = 0.049) and vertical force of the rear leg (p = 0.028). In conclusion, higher levels of EMG and ground reaction forces were generated during the flèche compared with the lunge, which promotes an improvement in the explosive force and contributes to a reduction in the movement phase of the entire offensive action.