Special Issue: Molecular Ecology, Physiology and Biochemistry of Insects 3.0.

With the outstanding work of Sir Vincent B [...].

Laparoscopic Electromyography and Electrostimulation of the Gastrointestinal Tract Before Placement of Theranostic Devices.

NEED: Electrical stimulation (ES) is a promising therapy for multisegmental gastrointestinal (GI) motility disorders such as gastroparesis with slow-transit constipation or chronic intestinal pseudo-obstruction. Wireless communicating GI devices for smart sensing and ES-based motility modulation will soon be available. Before placement, a potential benefit for each GI segment must be intraoperatively assessed. TECHNICAL SOLUTION: A minimally invasive multisegmental electromyography (EMG) analysis with ES of the GI tract is required. PROOF OF CONCEPT: Two porcine experiments were performed with a laparoscopic setup. Multiple hook-needle electrodes were subserosally applied in the stomach, duodenum, jejunum, ileum, and colon. EMG signals were acquired for computer-assisted motility analysis. Gastric ES, duodenal ES, jejunal ES, ileal ES, and colonic ES were applied. NEXT STEPS: Further technological and rapid regulatory solutions are desired to initialize a clinical trial of the next generation devices in the near future. CONCLUSION: We demonstrate a laparoscopic strategy with EMG analysis and ES of multiple GI segments. Thus, GI function may be evaluated before theranostic devices are placed. Extended GI resection or organ transplantation may be delayed or even avoided in affected patients.

A multi-Kalman filter-based approach for decoding arm kinematics from EMG recordings.

BACKGROUND: Remarkable work has been recently introduced to enhance the usage of Electromyography (EMG) signals in operating prosthetic arms. Despite the rapid advancements in this field, providing a reliable, naturalistic myoelectric prosthesis remains a significant challenge. Other challenges include the limited number of allowed movements, lack of simultaneous, continuous control and the high computational power that could be needed for accurate decoding. In this study, we propose an EMG-based multi-Kalman filter approach to decode arm kinematics; specifically, the elbow angle (θ), wrist joint horizontal (X) and vertical (Y) positions in a continuous and simultaneous manner. RESULTS: Ten subjects were examined from which we recorded arm kinematics and EMG signals of the biceps, triceps, lateral and anterior deltoid muscles corresponding to a randomized set of movements. The performance of the proposed decoder is assessed using the correlation coefficient (CC) and the normalized root-mean-square error (NRMSE) computed between the actual and the decoded kinematic. Results demonstrate that when training and testing the decoder using same-subject data, an average CC of 0.68 ± 0.1, 0.67 ± 0.12 and 0.64 ± 0.11, and average NRMSE of 0.21 ± 0.06, 0.18 ± 0.03 and 0.24 ± 0.07 were achieved for θ, X, and Y, respectively. When training the decoder using the data of one subject and decoding the data of other subjects, an average CC of 0.61 ± 0.19, 0.61 ± 0.16 and 0.48 ± 0.17, and an average NRMSE of 0.23 ± 0.07, 0.2 ± 0.05 and 0.38 ± 0.15 were achieved for θ, X, and Y, respectively. CONCLUSIONS: These results suggest the efficacy of the proposed approach and indicates the possibility of obtaining a subject-independent decoder.

[Suicidality in schizophrenic psychosis: a current overview]. / Suizidalität bei schizophrenen Psychosen: eine aktuelle Übersicht.

BACKGROUND: Suicidality in schizophrenic psychosis is an important topic but stands in clinical everyday work behind the perception of suicide especially in affective disorders. Schizophrenic psychosis is recognized as an independent risk factor for suicide attempts and suicides, whereas it poses particular challenges to the clinical professional due to the frequent unpredictability, abruptness and brutality of the methods used. For this reason, the suicide of a psychotic patient often leaves the professional and non-professional environment disturbed. AIMS: An overview of the existing relevant literature on suicide in psychosis is given. Explanations on the psychodynamics, indications on pharmacotherapy and psychotherapy and considerations on prevention round off this article and provide an up to date overview of this topic for clinicians. MATERIAL AND METHODS: A search was carried out in PubMed and Google scholar using the terms "suicide", "suicidality", "schizophrenia", "suicide AND schizophrenia", "suicide AND psychosis", "suicidality AND schizophrenia", "suicidality AND psychosis", "suicidality AND psychosis AND prevention", "suicide AND psychosis AND prevention", "suicidality AND schizophrenia AND prevention", "suicide AND schizophrenia AND prevention". CONCLUSION: Clinicians must have knowledge of the specific risk factors for suicide in psychotic patients, the characteristics of suicide in terms of design and temporal connection with treatment. The exploration and assessment of suicidality is often more difficult in psychotic patients than in affective or personality disorder patients, as there are often impulsive suicide attempts that can be explained by (suddenly occurring) psychotic symptoms and are therefore difficult or even impossible to foresee.

Robotic Setup Promises Consistent Effects of Multilocular Gastrointestinal Electrical Stimulation: First Results of a Porcine Study.

BACKGROUND: Electrical stimulation (ES) of several gastrointestinal (GI) segments is a promising therapeutic option for multilocular GI dysmotility, but conventional surgical access by laparotomy involves a high degree of tissue trauma. We evaluated a minimally invasive surgical approach using a robotic surgical system to perform electromyographic (EMG) recordings and ES of several porcine GI segments, comparing these data to an open surgical approach by laparotomy. MATERIALS AND METHODS: In 5 acute porcine experiments, we placed multiple electrodes on the stomach, duodenum, jejunum, ileum, and colon. Three experiments were performed with a median laparotomy and 2 others using a robotic platform. Multichannel EMGs were recorded, and ES was sequentially delivered with 4 ES parameters to the 5 target segments. We calculated pre- and poststimulatory spikes per minute (Spm) and performed a statistical Poisson analysis. RESULTS: Electrode placement was achieved in all cases without complications. Increased technical and implantation time were required to achieve the robotic electrode placement, but invasiveness was markedly reduced in comparison to the conventional approach. The highest calculated (c)Spm values were found in the poststimulatory period of the small bowel with both the conventional and robotic approaches. Six of the 20 Poisson test results in the open setup reached statistical significance and 12 were significant in the robotic experiments. CONCLUSIONS: The robotic setup was less invasive, revealed more consistent effects of multilocular ES in several GI segments, and is a promising option for future preclinical and clinical studies of GI motility disorders.

Short-pulsed laser for the treatment of tattoos, pigmented lesions, scars and rejuvenation.

This review describes the use of picosecond lasers for the treatment of tattoos, pigmented lesions, scars, and their use in rejuvenation. These devices have delivered enhanced efficacy for the treatment of tattoos and pigmented lesions when compared to the older 40-50 nanosecond devices. The fractional delivery with the picosecond devices have opened up a new method of rejuvenation for photodamaged skin and the treatment of scars. The delivery of these high-energy short pulses have created zones of injury in the skin referred to as areas of laser-induced optical breakdown. These areas of damage appear to produce cytokines and chemokines which result in epidermal and dermal repair and remodeling. The dual use of these devices with the flat and the fractional optics have made these devices useful in many ways that have been unanticipated.

Primate superior colliculus neurons activated by unexpected sensation.

Midbrain superior colliculus (SC) contains a variety of neuronal types, influencing a rich spectrum of functions beyond gaze orienting. Here, we report on a novel class of SC neurons in the rhesus monkey (Macaca mulatta) that are activated by an unexpected perturbation in a goal-directed arm-movement task. One monkey subject reached for and pressed an illuminated target on a working panel upon a visual go-signal, while maintaining visual fixation elsewhere. On 50 % of trials, a task perturbation occurred-the working panel abruptly and unexpectedly moved against the subject's hand after he pressed the target. During the performance, we recorded single SC neurons and found neurons activated exclusively for the task perturbation. These perturbation neurons were localized in the deep lateral zone of the SC, were silent during non-perturbed trials, did not appear to respond to task-irrelevant stimuli, and they had intriguingly long neuronal latencies. If the perturbation neurons' activity relates to the hand-target contact, it may reflect the saliency of an unexpected sensation, i.e. a sensation that is not self-induced and thus cannot be predicted on a basis of the monkey's motor program.

IDENTIFICATION OF THE FGL-AMIDE ALLATOSTATIN GENE OF THE PRIMITIVE TERMITE Mastotermes darwiniensis AND THE WOODROACH Cryptocercus darwini.

Allatostatins with the C-terminal ending Tyr/Phe-Xaa-Phe-Gly-Leu/Ile-amide (FGLa/ASTs) are widespread neuropeptides with multiple functions. The gene encoding the FGLa/AST polypeptide precursor was first isolated from cockroaches and since then could be identified in many insects and crustaceans. With its strictly conserved regions in combination with variable regions the gene seems to be a good candidate for phylogenetic analyses between closely and distantly related species. Here, the structure of the FGLa/AST gene of the most primitive termite, the giant northern termite Mastotermes darwiniensis Froggatt, was identified. The FGLa/AST gene of the woodroach Cryptocercus darwini was also determined. Precursor sequences of both species possess the general organization of dictyopteran FGLa/AST precursors containing 14 putative FGLa/AST peptides. In M. darwiniensis, only 11 out of the 14 FGLa/AST-like peptides possess the C-terminal conserved region Y/FXFGL/I/V/M and four of the putative peptide structures are not followed by a Gly residue that would lead to nonamidated peptides. Phylogenetic analyses show the high degree of similarity of dictyopteran FGLa/AST sequences. The position of termites, nested within the Blattaria, confirms that termites have evolved from primitive cockroaches.

Surface Electromyography Reliably Records Electrophysiologically Evoked Internal Anal Sphincter Activity: A More Minimally Invasive Approach for Monitoring Extrinsic Innervation.

BACKGROUND: Even in the case of minimally invasive pelvic surgery, sparing of the autonomic nerve supply is a prerequisite for maintaining anal sphincter function. Internal anal sphincter (IAS) innervation could be electrophysiologically identified based on processed electromyographic (EMG) recordings with conventional bipolar needle electrodes (NE). This experimental study aimed for the development of a minimally invasive approach via intra-anal surface EMG for recordings of evoked IAS activity. METHODS: Six male pigs underwent nerve-sparing low anterior rectal resection. Electric autonomic nerve stimulations were performed under online-processed EMG of the IAS. EMG recordings were simultaneously carried out with conventional bipolar NE as the reference method and newly developed intra-anal surface electrodes (SE) in different designs. RESULTS: In all experiments, the IAS activity could be continuously visualized via EMG recordings based on NE and SE. The median number of bipolar electric stimulations per animal was 27 (range 5-52). The neurostimulations resulted in significant EMG amplitude increases for both recording types [NE: median 3.0 µV (interquartile range, IQR 2.8-3.5) before stimulation vs. 7.1 µV (IQR 3.9-13.8) during stimulation, p < 0.001; SE: median 3.6 µV (IQR 3.1-4.3) before stimulation vs. 6.8 µV (IQR 4.8-10.3) during stimulation, p < 0.001]. CONCLUSIONS: Intra-anal SE enabled reliable EMG of electrophysiologically evoked IAS activity similar to the conventional recording via NE. The transfer of the method to access platforms for transanal total mesorectal excision or robotics may offer a practical more minimally invasive approach for monitoring extrinsic innervation.

Arm movements induced by electrical microstimulation in the superior colliculus of the macaque monkey.

Neuronal activity in the deep layers of the macaque (Macaca mulatta) superior colliculus (SC) and the underlying reticular formation is correlated with the initiation and execution of arm movements (Werner, 1993). Although the correlation of this activity with EMGs of proximal arm muscles is as strong as in motor cortex (Werner et al., 1997a; Stuphorn et al., 1999), little is known about the influence of electrical microstimulation in the SC on the initiation and trajectories of arm movements. Our experiments on three macaque monkeys clearly show that arm movements can be elicited by electrical microstimulation in the deep layers of the lateral SC and underlying reticular formation. The most extensively trained monkey, M1, extended his arm toward the screen in front of him more or less stereotypically upon electrical SC stimulation. In two other monkeys, M2 and M3, a larger repertoire of arm movements were elicited, categorized into three movement types, and compared before (M3) and after (M2 and M3) training: twitch (56% vs. 62%), lift (6% vs. 5%), and extend (37% vs. 32%), respectively. Therefore, arm movements induced by electrical stimulation in the monkey SC represent a further component of the functional repertoire of the SC using its impact on motoneurons in the spinal cord, probably via premotor neurons in the brainstem, as well as on structures involved in executing more complex movements such as target-directed reaching. Therefore, the macaque SC could be involved directly in the initiation, execution, and amendment of arm and hand movements.

Accurate and representative decoding of the neural drive to muscles in humans with multi-channel intramuscular thin-film electrodes.

Intramuscular electrodes developed over the past 80 years can record the concurrent activity of only a few motor units active during a muscle contraction. We designed, produced and tested a novel multi-channel intramuscular wire electrode that allows in vivo concurrent recordings of a substantially greater number of motor units than with conventional methods. The electrode has been extensively tested in deep and superficial human muscles. The performed tests indicate the applicability of the proposed technology in a variety of conditions. The electrode represents an important novel technology that opens new avenues in the study of the neural control of muscles in humans. We describe the design, fabrication and testing of a novel multi-channel thin-film electrode for detection of the output of motoneurones in vivo and in humans, through muscle signals. The structure includes a linear array of 16 detection sites that can sample intramuscular electromyographic activity from the entire muscle cross-section. The structure was tested in two superficial muscles (the abductor digiti minimi (ADM) and the tibialis anterior (TA)) and a deep muscle (the genioglossus (GG)) during contractions at various forces. Moreover, surface electromyogram (EMG) signals were concurrently detected from the TA muscle with a grid of 64 electrodes. Surface and intramuscular signals were decomposed into the constituent motor unit (MU) action potential trains. With the intramuscular electrode, up to 31 MUs were identified from the ADM muscle during an isometric contraction at 15% of the maximal force (MVC) and 50 MUs were identified for a 30% MVC contraction of TA. The new electrode detects different sources from a surface EMG system, as only one MU spike train was found to be common in the decomposition of the intramuscular and surface signals acquired from the TA. The system also allowed access to the GG muscle, which cannot be analysed with surface EMG, with successful identification of MU activity. With respect to classic detection systems, the presented thin-film structure enables recording from large populations of active MUs of deep and superficial muscles and thus can provide a faithful representation of the neural drive sent to a muscle.

SECRETION OF LIPASES IN THE DIGESTIVE TRACT OF THE CRICKET Gryllus bimaculatus.

Little is known concerning the sites and the ratios of the lipase secretions in insects, therefore we undertook an examination of the lipase secretion of fed and unfed adult female Gryllus bimaculatus. The ratio of triacylglyceride lipase, diacylglyceride lipase, and phosphatidylcholine lipase secreted by fed females in the caecum and ventriculus is 1:1.4:0.4. These activities decrease in the caecum by 30-40% in unfed females. The total lipase activity (TLA) in the caecum is about 10 times that in the ventriculus. Minimal lipase secretion occurs before and during the final moult, and remains at this level in unfed crickets, indicating a basal secretion rate. In 2-day-old fed females, about 10% of the TLA in the entire gut is found in the crop, about 70% in the caecum, 20% in the ventriculus, and 3% in the ileum. Lipases in the ventriculus are recycled back to the caecum and little is lost in the feces. Oleic acid stimulated in vitro lipase secretion, but lipids did not. Feeding stimulated lipase secretion, starvation reduced lipase secretion, but this does not prove a direct prandal regulation of secretion, because feeding also induced a size and volume increase of the caecum.

Visual selectivity for heading in the macaque ventral intraparietal area.

The patterns of optic flow seen during self-motion can be used to determine the direction of one's own heading. Tracking eye movements which typically occur during everyday life alter this task since they add further retinal image motion and (predictably) distort the retinal flow pattern. Humans employ both visual and nonvisual (extraretinal) information to solve a heading task in such case. Likewise, it has been shown that neurons in the monkey medial superior temporal area (area MST) use both signals during the processing of self-motion information. In this article we report that neurons in the macaque ventral intraparietal area (area VIP) use visual information derived from the distorted flow patterns to encode heading during (simulated) eye movements. We recorded responses of VIP neurons to simple radial flow fields and to distorted flow fields that simulated self-motion plus eye movements. In 59% of the cases, cell responses compensated for the distortion and kept the same heading selectivity irrespective of different simulated eye movements. In addition, response modulations during real compared with simulated eye movements were smaller, being consistent with reafferent signaling involved in the processing of the visual consequences of eye movements in area VIP. We conclude that the motion selectivities found in area VIP, like those in area MST, provide a way to successfully analyze and use flow fields during self-motion and simultaneous tracking movements.

Retinal ganglion cells projecting to the accessory optic system in optokinetic blind albinotic rats are direction-selective.

The optokinetic deficits in albinotic rats and ferrets are caused by the loss of direction selectivity in the accessory optic system (AOS). However, the underlying mechanisms for this loss are still not clear. Here we tested the hypothesis that, in albino rats, the retinal input to the AOS lacks direction selectivity and, as a consequence, neurons in the AOS are direction non-selective. We investigated ON-center direction-selective retinal ganglion cells, the major input to the AOS, in pigmented Long Evans and albino Wistar rats using extracellular in vitro patch-clamp techniques. To visualise putative AOS-projecting direction-selective ganglion cells, we retrogradely labeled them by injection of the infrared-sensitive dye indocyanine green into the medial terminal nucleus of the AOS. The present study is the first to present physiological evidence for retinal ON-center direction-selective ganglion cells in rat. Our results show that, in albinotic and pigmented rats, ON-center retinal ganglion cells projecting to the AOS are similarly direction-selective, suggesting that the optokinetic deficit must be caused by the abolition of direction selectivity in the AOS itself.

Development, manufacturing and application of double-sided flexible implantable microelectrodes.

Many neuroprosthetic applications require the use of very small, flexible multi-channel microelectrodes (e.g. polyimide-based film-like electrodes) to fit anatomical constraints. By arranging the electrode contacts on both sides of the polyimide film, selectivity can be further increased without increasing size. In this work, two approaches to create such double-sided electrodes are described and compared: sandwich electrodes prepared by precisely gluing two single-sided structures together, and monolithic electrodes created using a new double-sided photolithography process. Both methods were successfully applied to manufacture double-sided electrodes for stimulation of the vestibular system. In a case study, the electrodes were implanted in the semicircular canals of three guinea pigs and proven to provide electrical stimulation of the vestibular nerve. For both the monolithic electrodes and the sandwich electrodes, long-term stability and functionality was observed over a period of more than 12 months. Comparing the two types of electrodes with respect to the manufacturing process, it can be concluded that monolithic electrodes are the preferred solution for very thin electrodes (<20 µm), while sandwich electrode technology is especially suitable for thicker electrodes (40-50 µm).

Ready-to-use abobotulinumtoxinA solution versus powder botulinumtoxinA for treatment of glabellar lines: Investigators' and subjects' experience in a Phase IV study.

BACKGROUND: Botulinum neurotoxin type A (BoNT-A) is well-established for treatment of glabellar lines (GLs), and mostly formulated as powders requiring reconstitution for injection. The approved liquid formulation, ready-to-use (RTU) abobotulinumtoxinA was developed to ease injection procedures and prevent reconstitution errors. This multicenter, open-label, Phase IV study evaluated GL treatment experience using RTU abobotulinumtoxinA versus powder BoNT-A (onabotulinumtoxinA). METHODS: Females with experience of BoNT-A facial treatment were randomized 2:1 to GL treatment with 50 U RTU abobotulinumtoxinA (N = 99) or 20 U powder BoNT-A (N = 51) and followed-up for 6 months or 1 month, respectively. Assessments included: time to prepare each product for injection (primary endpoint); investigators' experience with product preparation/reconstitution; investigators' and subjects' treatment experience; safety; and for the RTU product: aesthetic improvement of GLs; subject satisfaction. RESULTS: Compared with powder BoNT-A, RTU abobotulinumtoxinA required statistically significantly less preparation time (mean 0:33 vs. 1:34 min: s; p < 0.0001). Investigators preferred RTU abobotulinumtoxinA over powder BoNT-A (81% of treatment sessions) and found it allowed more time to communicate with subjects (97%). All investigators (100%) also found it easy-to-use, easy-to-learn, and that it fulfilled their expectations. Subjects found the RTU abobotulinumtoxinA treatment comfortable (91%), and through 6 months posttreatment, most reported satisfaction with their appearance (≥88%), looking natural (≥95%) and refreshed (≥80%). At Month 1, 99% of RTU-treated subjects had investigator-assessed improved aesthetic appearance in GLs, maintained in 76% at Month 6. No serious adverse events occurred. CONCLUSION: RTU abobotulinumtoxinA for GL treatment is well-tolerated, efficacious, shows high levels of subject satisfaction throughout 6 months, saves time, and is preferred by clinicians over powder BoNT-A. GOV REGISTRY: NCT05277337.

Contribution of cholinergic and GABAergic mechanisms to direction tuning, discriminability, response reliability, and neuronal rate correlations in macaque middle temporal area.

Previous studies have investigated the effects of acetylcholine (ACh) on neuronal tuning, coding, and attention in primary visual cortex, but its contribution to coding in extrastriate cortex is unexplored. Here we investigate the effects of ACh on tuning properties of macaque middle temporal area MT neurons and contrast them with effects of gabazine, a GABA(A) receptor blocker. ACh increased neuronal activity, it had no effect on tuning width, but it significantly increased the direction discriminability of a neuron. Gabazine equally increased neuronal activity, but it widened tuning curves and decreased the direction discriminability of a neuron. Although gabazine significantly reduced response reliability, ACh application had little effect on response reliability. Finally, gabazine increased noise correlation of simultaneously recorded neurons, whereas ACh reduced it. Thus, both drugs increased firing rates, but only ACh application improved neuronal tuning and coding in line with effects seen in studies in which attention was selectively manipulated.

Cortical processing of saccade-related efference copy signals in patients with cerebellar lesion.

The updating of visual space across saccades is thought to rely on efference copies of motor commands. In humans, thalamic lesions impair performance on a saccadic double-step task, which requires the use of efference copy information, and the altering of saccade-related efference copy processing. This deficit is attributed to disruption of a pathway from the superior colliculus to the frontal eye field. However, the cerebellum is probably also involved in efference copy processing, due to its pivotal role for predictive motor control. The present study investigated the processing of efference copy information in eight patients with focal cerebellar lesions and 22 healthy controls by means of a saccadic double-step task with simultaneous event-related potential recording. Despite intact behavioural performance, a positive event-related potential component between 150 and 450 ms after first saccade onset in the updating condition, which has been interpreted in terms of the integration of efference copy signals with motor intentions for a subsequent saccade, was markedly reduced in the patients. These findings suggest that the cerebellum contributes to on-line saccade monitoring, and that cerebellar lesions alter saccade-related efference copy processing. However, given the intact behavioural performance, the reduced positivity in the patients may indicate that cerebellar damage is accounted for by either exploiting reduced saccade-related information, or making use of compensatory strategies to circumvent a deficit in using efference copy information procured by the cerebellum. The present study extends previous findings on the neural underpinnings of saccadic updating and further elucidates the mechanisms underlying cerebellar predictive motor control.