Increase In Electrical Activity Research Articles

Automatic detection of epileptic seizure using machine learning-based IANFIS-LightGBM system

A sudden increase in electrical activity in the brain is a defining feature of one of the severe neurological diseases known as epilepsy. This abnormality appears as a seizure, and identifying seizures is an important field of research. An essential technique for examining the features of neurological issues brain activities, and epileptic seizures is electroencephalography (EEG). In EEG data, analyzing epileptic irregularities visually requires a lot of time from neurologists. For accurate detection of epileptic seizures, numerous scientific techniques have been used with EEG data, and most of these techniques have produced promising results. For EEG signal classification with a high classification accuracy rate, the present research proposes an enhanced machine learning-based epileptic seizure detection model. The present research provides a hybrid Improved Adaptive Neuro-Fuzzy Inference System (IANFIS)-Light Gradient Boosting Machine (LightGBM) technique for automatically detecting and diagnosing epilepsy from EEG data. The experimental findings were supported by EEG records made available by the German University of Bonn and scalp EEG data acquired at Children’s Hospital Boston. The suggested IANFIS-LightGBM, according to the results, offers the most significant classification accuracy ratings in both situations.

Effect of sports shoe weight on lower limb muscle activities in athletes with ACL reconstruction during walking

Background. Different shoe weights affect walking mechanics. Therefore, the purpose of this study was to determine the effect of sport shoe weight on lower extremity muscle activities in athletes with anterior cruciate ligament reconstruction during walking. It was hypothesized that reduced shoe weight results in decreased frequency content of selected muscles during walking. Methods. Twenty healthy males and athletes with ACL reconstruction volunteered and gave their written informed consent to participate in this study. Participants were male and physically active. Each participant performed three walking trials in each of the light (mass per shoe: 150 ± 18 g), medium (300 ± 18 g), and heavy (450 ± 18 g) conditions in a randomized order and electromyography were analyzed during shod walking. Results. EMG results showed that the increase in shoe weight was directly related to the increase in electrical activity of the muscles, but only in the swing phase was the electrical activity of the TA muscle decreased. Conclusion. Different shoe weights affect the electrical activity of the muscles and the walking speed. Therefore, lighter weight shoes are recommended for patients with ACL. Practical Implications. The results of this study show that light shoes are useful for patients with anterior cruciate ligament rupture and the use of lightweight shoes is recommended for people with anterior cruciate ligament rupture.

Determination of activity of reflexogenic zones of the body during performance of static exercise of Hatha Yoga (Vakrasana)

By measuring the electrical conductivity on different meridians of the human body, you can get data on different meridian energies. The aim of our work was to determine the means of acupuncture diagnostics according to the method of Y. Nakatani the effect of exercise on the body on the example of static exercise, which is performed similar to the exercise Vakrasana (Snail pose from Hatha Yoga). We chose this exercise because of its static performance and ease of study. In our work, we suggested that the use of this technique is possible not only for the diagnosis of diseases, but also to determine the impact of exercise on certain organs and systems of the body. Ten students of DSPU named after I. Franko 18-20 years old, who had a perfect technique for performing these exercises. Measurements were taken before the exercise, during and after the exercise after 6 minutes. The results of the research showed significant changes in the indicators of electrical activity in the representative points of the meridians of the human body. The chosen static exercise has a very significant effect on the human body.
 An increase in electrical activity in the meridians of the human body, which, according to the literature, are responsible for the functions of the kidneys, liver, gall bladder, lymphatic and immune system. In addition, the analysis of the results showed that this asana suppresses the activity of the bladder and pancreas.
 Thus, our chosen method of acupuncture diagnostics allows us to determine the electrical activity of the meridians of the human body during static exercise.
 It is possible to offer use of this technique of research of influence of static exercises on a human body along with other generally accepted scientific methods.

Masticatory muscle activity in complete denture wearers: a surface electromyographic analysis

The investigation of the adaptation process to a new denture is relevant to understand the control of muscles. Surface electromyography provide reproducible data of masticatory muscle function and helps to assess the performance of dentures. This longitudinal study simultaneously evaluated electric potential in masseter and anterior temporalis during clenching at maximum intercuspation position and mastication at 2 months after denture insertion and one year later was done in complete denture patients. The surface electrodes were placed in anterior temporalis and ma-sseter region of 22 patients during maximum voluntary clenching and chewing. Statistical analysis was performed by paired t-test. A significant increase in electrical activity was found during clenching and chewing after one year compared to two months. The overall mean EMG value of masseter was significantly higher during chewing at 2 months (p<0.001) and 1 year (p<0.001). A negative correlation was found with respect to age and EMG value of ma-sseter. It is concluded that the electrical activity presented statistically significant difference after one year indicating improved functional quality. A good rehabilitation improves the efficiency of muscles. Monitoring the effect of rehabili-tation on stomatognathic system help to preventively warn about dysfunctions and treatment modifications needed.

Mitochondrial ROS as a regulator of synaptic function.

Exacerbated emission of reactive oxygen species (ROS) from presynaptic mitochondria is a well-studied hallmark of several neurodegenerative diseases, including amyotrophic lateral sclerosis. Outside of the context of disease, the potential role of mitochondrial ROS in presynaptic function and plasticity remains largely understudied. Here, we investigated this potential role by combining electrophysiological recordings, confocal imaging, immunohistochemical staining, and optogenetics using a well-established protocol for induction and measurement of synaptic potentiation in drosophila neuromuscular preparations. We have previously found that optogenetic induction of ROS emission from presynaptic mitochondria expressing mito-killer red was accompanied by an increase in spontaneous mini junction potentials. The increase in electrical activity did not appear to be associated with major synaptic structure alterations such as the formation of presynaptic filopodia or the growth of ghost boutons. However, in existing boutons, we observed an increase in active zone markers such as nc82/Brp. We have not detected Wnt1/Wg release from synaptic boutons suggesting the involvement of other signaling pathways that underlie observed changes in electrophysiological activity mediated by ROS emission. Future studies will further inquire the role of mitochondrial ROS in synaptic potentiation, as well as the potential signaling targets of mitochondrial ROS in the presynaptic structure.

Herbivore-induced Ca2+ signals trigger a jasmonate burst by activating ERF16-mediated expression in tomato.

Herbivory severely affects plant growth, posing a threat to crop production. Calcium ion (Ca2+ ) signaling and accumulation of jasmonates (JAs) are activated in plant response to herbivore attack, leading to the expression of defense pathways. However, little is known about how the Ca2+ signal modulates JA biosynthesis. We used diverse techniques, including CRISPR/Cas9, UPLC-MS/MS and molecular biology methods to explore the role of ETHYLENE RESPONSE FACTOR 16 in Ca2+ signal-triggered JA burst during herbivore defense in tomato. Here we show that simulated herbivory induces GLUTAMATE RECEPTOR LIKE3.3/3.5 (GLR3.3/3.5)-dependent increases in electrical activity, Ca2+ influx and increases the abundance of CALMODULIN2 (CaM2) and ERF16 transcripts in tomato. The interaction between CaM2 and ERF16 promotes JA biosynthesis by enhancing the transcriptional activity of ERF16, which increases the activation of ERF16 expression and causes expression of LIPOXYGENASE D (LOXD), AOC and 12-OXO-PHYTODIENOIC ACID REDUCTASE 3 (OPR3), the key genes in JA biosynthesis. Mutation of CaM2 results in decreased JA accumulation, together with the expression of JA biosynthesis-related genes, leading to reduced resistance to the cotton bollworm Helicoverpa armigera. These findings reveal a molecular mechanism underpinning the Ca2+ signal-initiated systemic JA burst and emphasize the pivotal role of Ca2+ signal/ERF16 crosstalk in herbivore defense.

Determination of activity of reflexogenic zones of the body during performance of static exercise of Hatha Yoga (Pashimottanasana)

By measuring the electrical conductivity on different meridians of the human body, you can get data on different meridian energies. The aim of our work was to determine the means of acupuncture diagnostics according to the method of Y. Nakatani the effect of exercise on the body on the example of static exercise, which is performed similar to the exercise Pashimottanasana (leaning forward from a sitting position with Hatha Yoga). We chose this exercise because of its static performance and ease of study. In our work, we suggested that the use of this technique is possible not only for the diagnosis of diseases, but also to determine the impact of exercise on certain organs and systems of the body. Ten students of DSPU named after I. Franko 18-20 years old, who had a perfect technique for performing these exercises. Measurements were taken before the exercise, during and after the exercise after 6 minutes. The results of the research showed significant changes in the indicators of electrical activity in the representative points of the meridians of the human body. The chosen static exercise has a very significant effect on the human body. An increase in electrical activity in the meridians of the human body, which, according to the literature, are responsible for the functions of the respiratory, lymphatic and immune systems, liver, kidneys, bladder, stomach, small and large intestines. In addition, the analysis of the results showed that this asana suppresses the activity of the cardiovascular system and gallbladder. Thus, our chosen method of acupuncture diagnostics allows us to determine the electrical activity of the meridians of the human body during static exercise. It is possible to offer use of this technique of research of influence of static exercises on a human body along with other generally accepted scientific methods.

Impact of a 10-min typing task in the development of trapezius myalgia: a preliminary observational study

Objectives. Computer use, as in typing, might contribute to trapezius myalgia (TM) development by increasing upper trapezius (UT) muscle fatigue. The purpose of this study is to investigate whether 10 min of performing a typing task by a population at risk would show significant changes in surface electromyography (sEMG) and pressure pain threshold (PPT) measurements. Supported and unsupported forearms postures are compared. Methods. Sixteen asymptomatic volunteers with minimum daily use of a computer of 5 h were randomized into two groups: fully supported forearms (n = 8) and unsupported forearms (n = 8). The protocol consisted of 10 min of a typing task, and the workstation was set according to the usual participant profile. sEMG and PPT readings were collected from both UT muscles. Results. PPT and sEMG readings were not significantly different among the two groups. Supported forearms had less reduction of PPT and a smaller increase in electrical activity. Conclusions. Ten minutes of typing seems insufficient to observe any significant changes that could lead to TM development.

DETERMINATION OF THE ACTIVITY OF REFLEXOGENIC ZONES OF THE BODY DURING THE PERFORMANCE OF STATIC EXERCISE OF HATHA YOGA (DHANURASANA)

By measuring the electrical conductivity of different meridians of the human body data can be obtained to demonstrate the meridian energies. Such non-invasive methods are used to stimulate acupuncture points on the meridians. There is a need to confirm the effectiveness of mechanisms of acupuncture for the human body using scientific methods. Measuring the electrical conductivity of different meridians provides indicators for interpretation. The aim of our study is to establish the possibility of using the method of studying the effect of exercise on the body by means of acupuncture diagnostics according to J.Nakatani’s method on the example of static exercise, which is performed similarly to Dhanurasana (outside the bow in Hatha Yoga). Ten female students were examined. Measurements were taken before the exercise, during and after the exercise after 6 minutes. The results of the research showed significant changes in the indicators of electrical activity in the representative points of the meridians of the body. An increase in electrical activity in the meridians of the human body, which are responsible for the functions of the respiratory, cardiovascular systems, kidneys and adrenal glands, gallbladder, small and large intestines, spleen, pancreas, liver and bladder, and its decrease in the meridian of the stomach. The method of acupuncture diagnostics chosen allows determining the electrical activity of the meridians of the human body during static exercise. It is possible to offer use of this technique of research of influence of physical exercises on a human body along with other generally accepted scientific methods.

The acute effect of knee brace on the electromyography activity of lower limb muscles in individuals with genu valgus during walking

Background: Different factors affect walking biomechanics disturb the postural control. Genu valgus is one of the most important lower limb malalignments that affects the postural control and disrupts the posture. The purpose of the present study was to investigate the acute effect of knee brace on the electromyography activity of lower limb muscles in individuals with genu valgus during walking. Methods: In this semi-experimental and a laboratory typ study,. 24 boys with genu valgum (20-30 years old) volunteered to participate in the study. The electrical activity of the selected muscles was recorded by an electromyography system during walking with and without knee brace. Paired t-test was used for statistical analysis at a significance level of 0.05. Results: There was a significant increase in electrical activity of the semitendinosus muscle during walking with knee brace compared to walking without it (p = 0.037, d = 0.89). The electrical activity of other lower limb muscles did not show any significant differences during acute use of knee brace (P >0.05). Conclusion: The semitendinosus muscle in individuals with genu valgus is weak. Therefore, significant increase in the electrical activity of the semitendinosus muscle during wearing of knee brace means delaying the fatigue and indicating improvement in the muscular function.

Determination of the functional state of the body using non-traditional research methods when performing the static exercise: "Prone press ups, static top position" (Cobra)

<p><strong>The aim</strong> of the work was to determine the electrical activity of the skin when performing a static exercise "Prone press ups, static top position (Cobra) ".</p><p><strong>Material and methods</strong>. Investigation of the effect of the selected static exercise was performed using the method of determining the electrical conductivity of representative points of the human body. Ten female students of 18-20 years who perfectly mastered the technique of performing the exercise were surveyed. The measurements were performed during, after and after 6 minutes.</p><p><strong>Results.</strong> Significant changes in indicators of electrical activity in representative points of the human body were revealed. Selected static exercise has a significant impact on the functional state of the person: according to Chinese folk medicine, stimulates the body points corresponding to the acupuncture meridians according to the classification of Chinese medicine cardiovascular, lymphatic and immune systems, colon and submucosa, mucosa spleen, small intestine.</p><p><strong>Conclusions</strong>. During the study of the effect of static exercise, it was found that the increase of electrical activity of the human body points, which, according to the literature, are responsible for the functions of the respiratory, cardiovascular, lymphatic and immune systems, the large intestine. This exercise also causes a decrease in electrical activity at representative points of the liver, stomach, and inhibits the activity of the small intestine, spleen, and pancreas. It is possible to propose the use of methods for determining the activity of human body points for the study of the influence of static exercises on the human body, along with other generally accepted scientific methods.</p>

Complex Oscillatory Waves Emerging from Cortical Organoids Model Early Human Brain Network Development.

Structural and transcriptional changes during early brain maturation follow fixed developmental programs defined by genetics. However, whether this is true for functional network activity remains unknown, primarily due to experimental inaccessibility of the initial stages of the living human brain. Here, we developed human cortical organoids that dynamically change cellular populations during maturation and exhibited consistent increases in electrical activity over the span of several months. The spontaneous network formation displayed periodic and regular oscillatory events that were dependent on glutamatergic and GABAergic signaling. The oscillatory activity transitioned to more spatiotemporally irregular patterns, and synchronous network events resembled features similar to those observed in preterm human electroencephalography. These results show that the development of structured network activity in a human neocortex model may follow stable genetic programming. Our approach provides opportunities for investigating and manipulating the role of network activity in the developing human cortex.

Randomised study of the effects of neuromuscular electrical stimulation and low-level laser therapy on muscle activation and pain in patients with knee osteoarthritis

Background The combined effects of low-level laser therapy and neuromuscular electrical stimulation on knee osteoarthritis have yet to be analysed. This study aimed to determine the individual and combined effects of laser therapy and electrical stimulation on muscle activation and pain in older people with knee osteoarthritis. Methods A total of 45 women aged 60–75 years with knee osteoarthritis were randomised into three groups to receive stimulation, laser or stimulation plus laser therapy. All three groups underwent a 4-week control period (without intervention) followed by an 8-week intervention period. The effects of the interventions on muscle inhibition, electrical activity and pain were analysed. Findings There was a decrease in muscle inhibition (effect size ≥0.6) and a reduction in pain (effect size >1.2) in all three groups. All therapies generated an increase in electrical activity (effect size 0.1–0.5). Conclusions Laser alone or in combination with electrical stimulation promoted similar increases in muscle activation and pain relief.

Визначення активності меридіанів тіла під час виконання статичної вправи

Мета роботи: визначення засобами акупунктурної діагностики за методикою Й. Накатані вплив виконання фізичних вправ на організм на прикладі статичної вправи, яка виконується подібно до Падмасани (поза Лотоса з Хатха-Йоги). Матеріал і методи. Обстежено десять студенток ДДПУ ім. І. Франка 18-20 років, які володіли досконалою технікою виконання обраної статичної вправи. Для визначення активності меридіанів тіла застосовувалась методика Ryodoraku за В. Накатані. Вимірювали електричний струм в репрезентативних біологічно активних точках дванадцяти головних меридіанів: легенів (Р), перикарда (МС), серця (С), лімфатичної та імунної систем (TR), тонкого (IG) і товстого (GI) кишківників, селезінки та підшлункової залози (RP), печінки (F), нирок (R), сечового (V) і жовчного (VB) міхурів та шлунка (E) з метою визначення можливості вивчення впливу фізичних вправ на організм методами акупунктурної діагностики. Вимірювання поводили до виконання вправи, під час та після виконання вправи через 6 хвилин. Результати. Виявлено достовірні зміни показників електричної активності у репрезентативних точках меридіанів тіла людини при виконанні обраної статичної вправи. Встановлено підвищення електричної активності у меридіанах тіла людини, які, за даними літератури, відповідають за функції тонкого і товстого кишечнику, підшлункової залози, селезінки, печінки, жовчного міхура, статевих залоз, нирок, наднирників. Також ця вправа викликає зниження електричної активності у репрезентативних точках органів дихання, серцево-судинної системи, сечового і жовчного міхурів та шлунку. Висновок. Показано, що використання методики Ryodoraku за В. Накатані вимірювання меридіанів при виконанні статичної вправи аналогічно пози «Падмасана» в системі Хатха_Йога дозволяє спостерігати активізацію меридіанів тіла, які, за даними літератури, відповідають за функції тонкого і товстого кишечнику, підшлункової залози, селезінки, печінки, жовчного міхура, статевих залоз, нирок, наднирників.

Modulatory effect of dopamine receptor 5 on the neurosecretory Dahlgren cells of the olive flounder, Paralichthys olivaceus

A neuromodulatory role for dopamine has been reported for magnocellular neuroendocrine cells in the mammalian hypothalamus. We examined its potential role as a local intercellular messenger in the neuroendocrine Dahlgren cell population of the caudal neurosecretory system (CNSS) of the euryhaline flounder Paralichthys olivaceus. In vitro application of dopamine (DA) caused an increase in electrical activity (firing frequency, recorded extracellularly) of Dahlgren cells, recruitment of previously silent cells, together with a greater proportion of cells showing phasic (irregular) activity. The dopamine precursor, levodopa (L-DOPA), also increased firing frequency, cell recruitment and enhanced bursting and tonic activity. The effect of dopamine was blocked by the D1, D5 receptor antagonist SCH23390, but not by the D2, D3, D4 receptor antagonist amisulpride. Transcriptome sequencing revealed that all DA receptors (D1, D2, D3, D4, and D5) were present in the flounder CNSS. However, quantitative RT-PCR revealed that D5 receptor mRNA expression was significantly increased in the CNSS following dopamine superfusion. These findings suggest that dopamine may modulate CNSS activity in vivo, and therefore neurosecretory output, through D5 receptors.

The behaviour of pelvic floor muscles during uterine contractions in spontaneous and oxytocin-induced labour

Term pregnant women were divided into oxytocin infusion and control groups. The electrical activities of pelvic floor muscles (PFM) were recorded at rest and during contractions electromyographically. The beginning and the end of each contraction were marked on the recorded electromyographic trace. A trace was regarded as ‘negative’ if no increase in electrical activity was observed and ‘positive’ if increased electrical activity was observed during the contractions. To evaluate the relative frequency of the areas of electrical activity during uterine contractions (UC) a ‘positive electrical activity percentage’ was used and calculated as: (total count of positive electrical activity areas)/(total count of UC) × 100. Positive and negative electrical activity percentages were compared. The percentages were significantly different between the groups (p <.01). Positive traces increased in 56.1 and 18.8% in study and control groups, respectively, (p < .01). Multiparous women showed more positive traces than nulliparous women, both in oxytocin-treated and spontaneous labour groups (p < .01). The rate of performed episiotomies was higher in the oxytocin-infused labours (p = .01). During physiological labour contractions the predominant behaviour of PFM seemed to be a relative silent status compared to a more contractile status caused by oxytocin administration. Contracted muscles may produce a counterpressure against expulsive UC leading to obstetrical injuries of these muscles and clinically higher rates in episiotomy decisions. This is the first report of behaviour of PFM during labour contractions and further prospective studies are needed to assess the role of oxytocin administration on PFM and associated clinical consequences.Impact statementWhat is already known on this subject? The physiological functions of pelvic floor muscles depend on the coordinated actions of these muscles and rely also on unique interactions between the somatic and autonomic nervous systems. Oxytocin is commonly used for the induction and augmentation of uterine contractions and such an induced labour may be more painful for the woman.What do the results of this study add? Pelvic floor muscles tend to contract more frequently during uterine contractions as labour progresses. This difference was more pronounced in labours which were treated with oxytocin infusion.What are the implications of these findings for clinical practice and/or further research? This is the first report of electrophysiological behaviour of pelvic floor muscles during labour contractions in spontaneous and oxytocin-induced labour. Oxytocin administration seems to interfere with the coordination of uterine and pelvic floor muscle contractions. This study may be of interest for researchers to investigate the effect of the worldwide liberal use of oxytocin for induction of labour on pelvic floor muscle damage during parturition.

Modulatory effect of glutamate GluR2 receptor on the caudal neurosecretory Dahlgren cells of the olive flounder, Paralichthys olivaceus

A neuromodulatory role for glutamate has been reported for magnocellular neuroendocrine cells in mammalian hypothalamus. We examined the potential role of glutamate as a local intercellular messenger in the neuroendocrine Dahlgren cell population of the caudal neurosecretory system (CNSS) in the euryhaline flounder Paralichthys olivaceus. In pharmacological experiments in vitro, glutamate (Glu) caused an increase in electrical activity of Dahlgren cells, recruitment of previously silent cells, together with a greater proportion of cells showing phasic (irregular) activity. The glutamate substrate, glutamine (Gln), led to increased firing frequency, cell recruitment and enhanced bursting activity. The glutamate effect was not blocked by the N-methyl-D-aspartate (NMDA) receptor antagonist MK-801, or the GluR1/GluR3 (AMPA) receptor antagonist IEm1795-2HBr, but was blocked by the broad-spectrum α-amino-3-hydroxy- 5- methyl-4-isoxazo-lepropionic acid (AMPA) receptor antagonist ZK200775. Our transcriptome sequencing study revealed three AMPA receptor (GluR1, GluR2 and GluR3) in the olive flounder CNSS. Quantitative RT-PCR revealed that GluR2 receptor mRNA expression was significant increased following dose-dependent superfusion with glutamate in the CNSS. GluR1 and GluR3 receptor mRNA expression were decreased following superfusion with glutamate. L-type Ca2+ channel mRNA expression had a significant dose-dependent decrease following superfusion with glutamate, compared to the control. In the salinity challenge experiment, acute transfer from SW to FW, GluR2 receptor mRNA expression was significantly higher than the control at 2 h. These findings suggest that GluR2 is one of the mechanisms which can medicate glutamate action within the CNSS, enhancing electrical activity and hence secretory output.

Immediate effect of myofascial release on range of motion, pain and biceps and rectus femoris muscle activity after total knee replacement

ObjectivesThe role of a myofascial release (MFR) on flexion contractures after total knee arthroplasty (TKA) has not yet been elucidated. Therefore, the purpose of this study was to determine its immediate effect on such patients. MethodsIn this A-B single subject experimental study, 33 TKA's patients with knee flexion contracture had their gluteal, posterior fascia lata, posterior crural and plantar fasciae released. Patients' knee range of motion (KROM), pain and muscle electric activity were assessed pre- and post-intervention. ResultsAn increase in electric activity of the biceps femoris muscle was identified after treatment (pre RMS = 0.087 ± 0.066 V; post RMS = 0.097 ± 0.085 V; p = 0.037). Mean gain of KROM was 5.72 ± 6.27, correspondent to an 11.9% improvement (p = 0.01). Eight subjects had their pain decreased on 56.9% (p = 0.04). ConclusionsMFR increased muscle activity, reduced pain and improved the KROM of TKA patients. Thus, MFR is a useful resource of rehabilitation after TKA.

Does the habitual mastication side impact jaw muscle activity?

ObjectiveTo compare electrical activity in the anterior temporal and masseter muscles on the habitual (HMS) and non-habitual mastication side (NHMS), during mastication and in the mandibular postural position. In addition, the increase in electrical activity during mastication was assessed for the HMS and NHMS, analysing both working (WSM) and non-working side during mastication (NWSM). MethodsA total of 28 healthy women (18–32 years) participated in the study. They were submitted to Kazazoglu’s test to identify the HMS. Bioresearch ‘Bio EMG’ software and bipolar surface electrodes were used in the exams. The exams were conducted in the postural position and during the unilateral mastication of raisins, on both the HMS and NHMS. The working and non-working side on HMS and NHMS were assessed separately. The obtained data were then statistically analysed with SPSS 20.0, using the Paired Samples Test at a significance level of 95%. ResultsThe differences in the average EMG values between HMS and NHMS were not statistically significant in the postural position (Temporal p=0.2; Masseter p=0.4) or during mastication (Temporal WSM p=0.8; Temporal NWSM p=0.8; Masseter WSM p=0.6; Masseter NWSM p=0.2). Differences in the increase in electrical activity between the masseter and temporal muscles occurred on the working side, on the HMS and NHMS (p=0.0), but not on the non-working side: HMS (p=0.9) and NHMS (p=0.3). The increase in electrical activity was about 35% higher in the masseter than in the temporal muscle. ConclusionsMastication side preference does not significantly impact electrical activity of the anterior temporal and masseter muscles during mastication or in postural position.

Role of vasoactive intestinal peptide in the light input to the circadian system.

The neuropeptide vasoactive intestinal peptide (VIP) is expressed at high levels in a subset of neurons in the ventral region of the suprachiasmatic nucleus (SCN). While VIP is known to be important for the synchronization of the SCN network, the role of VIP in photic regulation of the circadian system has received less attention. In the present study, we found that the light-evoked increase in electrical activity in vivo was unaltered by the loss of VIP. In the absence of VIP, the ventral SCN still exhibited N-methyl-d-aspartate-evoked responses in a brain slice preparation, although the absolute levels of neural activity before and after treatment were significantly reduced. Next, we used calcium imaging techniques to determine if the loss of VIP altered the calcium influx due to retinohypothalamic tract stimulation. The magnitude of the evoked calcium influx was not reduced in the ventral SCN, but did decline in the dorsal SCN regions. We examined the time course of the photic induction of Period1 in the SCN using insitu hybridization in VIP-mutant mice. We found that the initial induction of Period1 was not reduced by the loss of this signaling peptide. However, the sustained increase in Period1 expression (after 30min) was significantly reduced. Similar results were found by measuring the light induction of cFOS in the SCN. These findings suggest that VIP is critical for longer-term changes within the SCN circuit, but does not play a role in the acute light response.