Difference in Radiosensitivity Depending on the Presence and Absence of EGFR Mutations: Clinical and In Vitro Analyses

PURPOSE/OBJECTIVE(S)

For stage IV non-small cell lung cancer (NSCLC), the treatment drug is selected based on the gene mutation status. However, the dose or field of radiation therapy is not change based on the genetic status. We evaluated both clinical and in vitro data, showing that the presence or absence of epidermal growth factor receptor (EGFR) mutations affects radiosensitivity in patients with brain metastases (BM) from NSCLC.

MATERIALS/METHODS

Patients with BM from NSCLC who received whole brain radiotherapy (WBRT) were enrolled in this study. Patient characteristics are shown in the Table. EGFR mutations were observed in 13 (31.0%) patients. The prescribed dose was 30 Gy in 10 fractions (85.7%). The A549, VMRC-LCD, NCI-H1975, and HCC4006 cell lines were used for the in vitro study. EGFR mutation was negative in A549 and VMRC-LCD and positive in NCI-H1975 (exon21) and HCC4006 (exon19). After irradiation of these cell lines with 0, 2, 4, and 8 Gy, a colony formation assay was performed. DNA double-strand breaks (DSBs) were assessed 30 min and 24 h after 4 Gy irradiation using γH2AX.

RESULTS

The median follow-up period was 4 months (range, 1-35). Intracranial recurrence was observed in 14 (33.3%) patients during the follow-up period. Thirty-nine (92.9%) patients died during the follow-up period. Patients with EGFR mutation-positive tumors had significantly better intracranial control rates than those with EGFR mutation-negative tumors (p = 0.0213). A similar tendency was observed in the analysis conducted, except for the cases in which tyrosine kinase inhibitor (TKI) was administered after WBRT. In the EGFR mutation-positive group, no significant difference was observed between patients who received TKI after WBRT and those who did not (p = 0.527). In the colony formation assay, EGFR mutation-positive cell lines showed a significantly lower number of colonies formed after irradiation with 2 and 4 Gy than mutation-negative cell lines (p = 0.00018 and 0.0000291, respectively). EGFR mutation-positive cell lines had significantly more DNA-DSBs remaining 24 h after irradiation than mutation-negative cell lines (p = 0.0000000312).

CONCLUSION

Our data suggest that patients with EGFR mutation-positive NSCLC are more radiosensitive than those with negative EGFR mutations.

Deep-Inspiration Breath-Hold Stereotactic Body Radiation Therapy by Combining Spirometer-Guided Breath-Hold and a Real-Time Tumor Tracking System: A Novel Approach

PURPOSE/OBJECTIVE(S)

There are several methods used against respiratory motion (RM). Expiratory breath-hold (BH) is considered more stable and reproducible than inspiratory BH; therefore, BH with spirometry is often used for expiration. The real-time tumor tracking radiotherapy (RTRT) system is a highly effective method for reducing the margin of RM. This system ambushes and irradiates tumors during the expiratory phase when tumors move slowly. Although these methods usually involve expiration, it is advantageous to expand the lungs with inspiration to reduce the risk of adverse events. Here, we developed a new approach of performing stereotactic body radiation therapy (SBRT) under deep-inspiration BH (DIBH) by combining these two methods.

MATERIALS/METHODS

Lung tumors with respiratory motion ≥ 1 cm were included. Three or four fiducial markers were placed near the tumor via bronchoscopy. DIBH CT (CT-IN) was performed under the guidance of spirometer. The PTV was obtained by adding a 5-mm margin to the GTV delineated on CT-IN. The prescribed dose was 42 Gy in four fractions for the D95 of the PTV. An error of 2.0 mm around the planned position of the fiducial marker on CT-IN was permitted along each orthogonal axis as a gating box. In preparation for cases in which the reproducibility of DIBH is low and treatment cannot be performed, light expiration BH CT (CT-EX) was also performed, and a radiotherapy plan was prepared for the conventional RTRT system so that it could be switched at any time. Lung volumes and doses (mean dose, V20 Gy, V10 Gy, and V5 Gy) on CT-EX and CT-IN were compared.

RESULTS

Five patients underwent SBRT with DIBH, and all completed the planned irradiation course. The median treatment time per fraction was 27.86 min (range, 25.5-40.6). Four tumors were located in the left lower lobe and one in the right lower lobe. The median volume of PTV was 12.4 (range, 5.2-26.2) mL. The lung volumes and doses on CT-EX and CT-IN are shown in the Table. The lung volume on CT-IN was 1.6 times larger than that on CT-EX. The PTV-to-lung ratio on CT-IN was significantly lower than that on CT-EX. V20 Gy and V10 Gy on CT-IN were significantly lower than those on CT-EX.

CONCLUSION

SBRT with DIBH was achieved by combining the spirometer and RTRT system. This can help to eliminate concerns about reproducibility and high-speed tumor movement during inspiration, which are weaknesses of spirometer-guided breath-hold and the RTRT system, respectively, while ensuring the accuracy of the RTRT system. DIBH SBRT is a promising method that can reduce lung dose.

Masticatory Behavior Change with a Wearable Chewing Counter: A Randomized Controlled Trial

Because a relationship has been reported between masticatory behavior, obesity, and postprandial blood glucose, it is recommended to chew well and take a longer time to eat. The purpose of this study was to examine the possibility of changing masticatory behavior using a small ear-hung wearable chewing counter, which can monitor masticatory behavior without disturbing daily meals. In total, 235 healthy volunteers participated in a 4-wk randomized controlled trial and were divided into 3 groups. All participants were instructed about the importance of mastication at the first visit. During the intervention, group B used the chewing counter without an algorithm during each meal (notification of the number of chews after meal), and group C used the chewing counter with a masticatory behavior change algorithm (setting a target value and displaying the number of chews in real time). Group A was set as the control group. The number of chews and the meal time when consuming 1 rice ball (100 g) were measured before and after the intervention using the chewing counter, and the rate of change in these values was evaluated. Participants also provided a subjective evaluation of their changes in masticatory behavior. The number of chews and the meal time of 1 rice ball increased significantly in groups B and C compared with before the intervention, and the rate of change was significantly higher in group C than in group A and group B. In addition, the subjective evaluation of the change in the number of chews was highest in group C. Self-monitoring of masticatory behavior by providing a target value and the degree of achievement for the number of chews using a wearable chewing counter with a behavioral change algorithm could promote effective change in masticatory behavior and lead to an increased number of chews. (Trial ID: UMIN000034476).

Involvement of Parvalbumin-Positive Neurons in the Development of Hyperalgesia in a Mouse Model of Fibromyalgia

Fibromyalgia (FM) presents as chronic systemic pain, which might be ascribed to central sensitization, in which pain information processing is amplified in the central nervous system. Since patients with FM display elevated gamma oscillations in the pain matrix and parvalbumin (PV)-positive neurons play a critical role in induction of gamma oscillations, we hypothesized that changes in PV-positive neurons are involved in hyperalgesia in fibromyalgia. In the present study, to investigate a role of PV-positive neurons in neuropathic pain, mice received reserpine administration for 3 consecutive days as an animal model of FM (RES group), while control mice received vehicle injections in the same way (VEH group). The mice were subjected to hot-plate and forced swim tests, and immuno-stained PV-positive neurons were counted in the pain matrix. We investigated relationships between PV-positive neuron density in the pain matrix and pain avoidance behaviors. The results indicated that the mice in the RES group showed transient bodyweight loss and longer immobility time in the forced swim test than the mice in the VEH group. In the hot-plate test, the RES group showed shorter response latencies and a larger number of jumps in response to nociceptive thermal stimulus than the VEH group. Histological examination indicated an increase in the density of PV-positive neurons in the primary somatosensory cortex (S1) in the RES group. Furthermore, response latencies to the hot-plate were significantly and negatively correlated with the density of PV-positive neurons in the S1. These results suggest a critical role for PV-positive neurons in the S1 to develop hyperalgesia in FM.

Involvement of the Rostromedial Prefrontal Cortex in Human-Robot Interaction: fNIRS Evidence From a Robot-Assisted Motor Task

Assistive exoskeleton robots are being widely applied in neurorehabilitation to improve upper-limb motor and somatosensory functions. During robot-assisted exercises, the central nervous system appears to highly attend to external information-processing (IP) to efficiently interact with robotic assistance. However, the neural mechanisms underlying this process remain unclear. The rostromedial prefrontal cortex (rmPFC) may be the core of the executive resource allocation that generates biases in the allocation of processing resources toward an external IP according to current behavioral demands. Here, we used functional near-infrared spectroscopy to investigate the cortical activation associated with executive resource allocation during a robot-assisted motor task. During data acquisition, participants performed a right-arm motor task using elbow flexion-extension movements in three different loading conditions: robotic assistive loading (ROB), resistive loading (RES), and non-loading (NON). Participants were asked to strive for kinematic consistency in their movements. A one-way repeated measures analysis of variance and general linear model-based methods were employed to examine task-related activity. We demonstrated that hemodynamic responses in the ventral and dorsal rmPFC were higher during ROB than during NON. Moreover, greater hemodynamic responses in the ventral rmPFC were observed during ROB than during RES. Increased activation in ventral and dorsal rmPFC subregions may be involved in the executive resource allocation that prioritizes external IP during human-robot interactions. In conclusion, these findings provide novel insights regarding the involvement of executive control during a robot-assisted motor task.

Direct visualization of the three-dimensional shape of skyrmion strings in a noncentrosymmetric magnet

Magnetic skyrmions are topologically stable swirling spin textures that appear as particle-like objects in two-dimensional (2D) systems. Here, utilizing scalar magnetic X-ray tomography under applied magnetic fields, we report the direct visualization of the three-dimensional (3D) shape of individual skyrmion strings in the room-temperature skyrmion-hosting non-centrosymmetric compound Mn_1.4Pt_0.9Pd_0.1Sn. Through the tomographic reconstruction of the 3D distribution of the [001] magnetization component on the basis of transmission images taken at various angles, we identify a skyrmion string running through the entire thickness of the sample, as well as various defect structures, such as the interrupted and Y-shaped strings. The observed point defect may represent the Bloch point serving as an emergent magnetic monopole, as proposed theoretically. Our tomographic approach with a tunable magnetic field paves the way for direct visualization of the structural dynamics of individual skyrmion strings in 3D space, which will contribute to a better understanding of the creation, annihilation and transfer of these topological objects.

[Neural Mechanisms of Innate Recognition of Facial Stimuli in Primates]

Primates can recognize or respond to specific stimuli that are important for survival, such as faces, predators, prey animals, and foods, even if they have not experienced those stimuli previously (innate recognition). Throughout vertebrates, including primates, the extrageniculate visual system (subcortical visual pathway) comprising the retina, superior colliculus, pulvinar, and amygdala is thought to be genetically hard-wired and involved in innate recognition of these stimuli. To investigate neural mechanisms of innate recognition in primates, we analyzed single neuronal responses to facial images in the monkey pulvinar and superior colliculus. The results indicated that the pulvinar and superior collicular neurons responded preferentially to facial images in short latency and showed gamma oscillations during stimulus presentation. Furthermore, the population activity of these neurons discriminated head direction, sex, and identity of facial images. Based on these findings, we discussed neural mechanisms underlying the innate and automatic (unconscious) detection of facial stimuli in the extrageniculate visual system.

Hyperacute postprocedural high platelet reactivity: a novel predictor for in-hospital adverse events in acute coronary syndrome with prasugrel loading

Introduction

Postprocedural High platelet reactivity (HPR) seems to associate long term adverse cardiovascular events, mainly intrastent thrombosis. However, the relationship between hyper-acute postprocedural HPR with prasugrel loading and clinical outcomes in acute coronary syndrome (ACS) is still unclear. Moreover, factors contributing HPR in ACS with prasugrel loading are also unknown.

Purpose

This study aimed to assess the impact of hyper-acute postprocedural HPR with prasugrel loading on clinical outcomes in ACS during hospitalization, as well as to define appropriate cut-off values and identify contributing factors of HPR.

Methods

We performed a single-centre, retrospective observational study that enrolled 207 patients who underwent emergent PCI for ACS with prasugrel loading. The P2Y12reaction unit (PRU) value was measured immediately after PCI with the VerifyNow System. The primary endpoint was major adverse cardiac events (MACE, defined as the composite of death, myocardial infarction, stroke, heart failure, ventricular arrhythmia needing defibrillation).

Results

Mean patient age (standard deviation) was 70.5 (±13.0) years, 78.7% were male, and average time from prasugrel intake to PRU calculation was 98.3 (±49.1) min. During a mean hospital stay of 15.9 (±9.3) days, there were 34 in-hospital MACE (16.4%) and 10 deaths (4.8%). Thrombosis events, didn't stand out and mechanical complications, such as cardiac rupture and cardiac tamponade occupies most of cardiovascular death which occurred before 10 days on admission. PRU was significantly higher in MACE group than Non-MACE group (279±65 vs 227±72, p<0.001 respectively). The ROC curve analysis of PRU for discriminating significant in-hospital MACE showed the cut off value of 293 (sensitivity:52.9%, specificity:83.2% [AUC=0.709, p<0.0001]). 47patients (29.4%) were thus categorized as HPR (PRU>293) immediately after emergent PCI. Kaplan-Meyer curve showed MACE events occurred in HPR group than non-HPR group (38.2% vs 10.0%, p<0.001). Multiple cox analysis demonstrated that HPR was independent predictors of MACE in patients with ACS underwent PCI (OR 5.416, 95% CI 2.157–13.598, p<0.0001). Multiple logistic regression model showed female sex, low haemoglobin value, and large mean platelet volume were independent predictors of HPR.

Conclusion

PRU was significantly higher in MACE group, and appropriate cut-off value of HPR in this study was 293. HPR was independent predictor of MACE during hospitalization, however thrombosis event was not significant. Evidence of clinical impact with postprocedural HPR within 120 minutes after prasugrel loading is scarce. This study shows post-procedural HPR, even without sufficient time after prasugrel intake, can be a useful predictive marker of adverse events during hospitalization.

Funding Acknowledgement

Type of funding sources: None. PRU between Non-MACE and MACE groupKaplan-Meyer curve

Cardio-ankle vascular index is useful screening method to detect obstructive coronary artery disease in asymptomatic diabetes patients with subclinical atherosclerosis

Background

Patients with diabetes mellitus are at very high risk for obstructive coronary artery disease; however, invasive coronary angiography is not allowed to apply in all patients. Cardio-ankle vascular index (CAVI), a marker of arterial stiffness has been reported to reflect atherosclerotic burden.

Purpose

To assess the diagnostic performance of CAVI vs. coronary calcium score for detecting obstructive coronary artery disease determined by Coronary CT angiography (CCTA) in asymptomatic diabetes patients.

Methods

During May 2015 to December 2019, 816 patients with diabetes mellitus were evaluated. First, intima-media thickness of carotid artery was measured in all subjects. Then, patients with intima-media thickness over 11mm underwent CAVI. Finally, 209 patients who have one or more cardiovascular risk factors other than diabetes mellitus were enrolled (68±11 years, 68% men). Patients were excluded if they had a disorder of the kidney, a prior history of coronary artery revascularization, atrial fibrillation, LV ejection fraction <50%, ABI <0.9 or allergy to contrast. Diagnostic performance of CAVI was evaluated with coronary stenosis >50% by CCTA.

Results

CAVI, Agatston score, and intima-media thickness of carotid artery were 9.2±1.3, 396±621 and 2.0±0.7mm, respectively. CAVI was significantly correlated with age (r=0.530, p<0.001), coronary artery calcification (r=0.182, p=0.008), and intima-media thickness of carotid artery (r=0.195, p=0.005). Among them, 108 patients (48%) had coronary stenosis. CAVI, Agatston score and intima-media thickness of carotid artery in patients with coronary stenosis were higher than that without coronary stenosis, respectively (9.8±1.1 vs 8.5±1.0, p<0.001, 526±676 vs. 255±525, p=0.001, 2.2±0.7 vs. 1.8±0.6, p<0.001). The ROC curve analysis of CAVI for discriminating coronary stenosis showed that the sensitivity 75.0% and specificity 77.2% at the cut off value of 9.23 (AUC=0.812, p<0.001). Contrastingly, diagnostic performance of coronary calcium score and intima-media thickness of carotid artery were less than CAVI (sensitivity: 91.7%, specificity: 56.4%, AUC=0.753, p<0.05 vs. CAVI, sensitivity: 68.5%, specificity: 59.4%, AUC=0.663, p<0.05 vs. CAVI). Multivariate logistic analysis demonstrated that CAVI was significantly associated with coronary stenosis (OR=4.133, p<0.001) after adjustment of conventional risk factors, although coronary calcium score was not correlated with coronary stenosis.

Conclusion

CAVI could be informative to select patients having obstructive coronary artery disease in asymptomatic diabetes patients with thick intima-media thickness.

Funding Acknowledgement

Type of funding sources: None.

Impact of high platelet reactivity on left ventricular remodeling in patients with acute coronary syndrome

Background/Introduction

Previous studies demonstrated that high platelet reactivity (HPR) predicts future cardiovascular death and coronary events in patients undergoing percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS). However, few studies have focused on the impact of HPR on left ventricular remodeling (LVR) and each echocardiographic parameter.

Purpose

The purpose of this study was to investigate the impact of HPR in ACS patients on LVR and changes in echocardiographic volume indexes and LV ejection fraction.

Methods

This is a retrospective cohort study of prospectively collected data in a single center that enrolled patients who underwent emergency PCI for ACS including STEMI and NSTEMI with prasugrel loading. The primary outcome of the study was LVR associated with HPR. Secondary endpoints were changes in indexed LVESV, LVEDV, LVEF, E/e' and LAVI between baseline and follow-up. The P2Y12 reaction unit (PRU) value in response to prasugrel was assessed by the VerifyNow P2Y12 assay. Blood samples were collected once per procedure immediately after PCI. LVR index was calculated as the relative change in LVEDV observed at follow-up compared with baseline. LVR was defined as a relative increase in LVEDV ≥20%, measured at follow-up visit compared with the baseline value before discharge.

Results

A total of 196 ACS patients who underwent emergency PCI between January 2016 and July 2020 were enrolled in the study. The mean age of the study population was 69.9 years, and 76.0% were male. On echocardiography at follow up visit of mean duration of 7.0±4.0 months, LVR was found in 38 patients (19.4%). The optimal cutoff for PRU associated with increased LVR assessed by receiver-operating characteristic curve analysis was 245.5 (AUC: 0.656; 95% CI: 0.564 to 0.749; p=0.003). On the basis of this cutoff, HPR was found in 82 patients (42.1%) and the prevalence of LVR was significantly higher in the HPR group compared to the non-HPR group (30.5% vs. 11.4%; p=0.001). Multiple Cox regression analysis showed that HPR was an independent predictor of LVR (OR 4.22, 95% CI 1.83–9.71, p=0.001). In addition, Δ% EDV and Δ% ESV increased in the HPR group, and decreased in the non-HPR group with significant differences (5.8±32.6% vs. −8.0±26.2% in Δ% EDV; p=0.002, 2.0±37.5% vs. −13.3±33.0% in Δ% ESV; p=0.004, respectively). Δ%EF, Δ%E/e', Δ%LAVI were numerically improved in the non-HPR group compared with the HPR group, but this difference did not reach statistical significance.

Conclusion

In patients with ACS, HPR defined as PRU ≥246 immediately after emergency PCI was an independent predictor of LVR in the chronic phase.

Funding Acknowledgement

Type of funding sources: None. Predictors of the presence of LVRChanges (Δ%) of LVEDV and LVESV

Rat Retrosplenial Cortical Involvement in Wayfinding Using Visual and Locomotor Cues

The retrosplenial cortex (RSC) has been implicated in wayfinding using different sensory cues. However, the neural mechanisms of how the RSC constructs spatial representations to code an appropriate route under different sensory cues are unknown. In this study, rat RSC neurons were recorded while rats ran on a treadmill affixed to a motion stage that was displaced along a figure-8-shaped track. The activity of some RSC neurons increased during specific directional displacements, while the activity of other neurons correlated with the running speed on the treadmill regardless of the displacement directions. Elimination of visual cues by turning off the room lights and/or locomotor cues by turning off the treadmill decreased the activity of both groups of neurons. The ensemble activity of the former group of neurons discriminated displacements along the common central path of different routes in the track, even when visual or locomotor cues were eliminated where different spatial representations must be created based on different sensory cues. The present results provide neurophysiological evidence of an RSC involvement in wayfinding under different spatial representations with different sensory cues.

Neuronal Representation of Locomotion During Motivated Behavior in the Mouse Anterior Cingulate Cortex

The anterior cingulate cortex (ACC) is located within the dorsomedial prefrontal cortex (PFC), and processes and facilitates goal-directed behaviors relating to emotion, reward, and motor control. However, it is unclear how ACC neurons dynamically encode motivated behavior during locomotion. In this study, we examined how information for locomotion and behavioral outcomes is temporally represented by individual and ensembles of ACC neurons in mice during a self-paced locomotor reward-based task. By recording and analyzing the activity of ACC neurons with a microdrive tetrode array while the mouse performed the locomotor task, we found that more than two-fifths of the neurons showed phasic activity relating to locomotion or the reward behavior. Some of these neurons showed significant differences in their firing rate depending on the behavioral outcome. Furthermore, by applying a demixed principal component analysis, the ACC population activity was decomposed into components representing locomotion and the previous/future outcome. These results indicated that ACC neurons dynamically integrate motor and behavioral inputs during goal-directed behaviors.

Preferential Neuronal Responses to Snakes in the Monkey Medial Prefrontal Cortex Support an Evolutionary Origin for Ophidiophobia

Ophidiophobia (snake phobia) is one of the most common specific phobias. It has been proposed that specific phobia may have an evolutionary origin, and that attentional bias to specific items may promote the onset of phobia. Noninvasive imaging studies of patients with specific phobia reported that the medial prefrontal cortex (mPFC), especially the rostral part of the anterior cingulate cortex (rACC), and amygdala are activated during the presentation of phobogenic stimuli. We propose that the mPFC-amygdala circuit may be involved in the pathogenesis of phobia. The mPFC receives inputs from the phylogenically old subcortical visual pathway including the superior colliculus, pulvinar, and amygdala, while mPFC neurons are highly sensitive to snakes that are the first modern predator of primates, and discriminate snakes with striking postures from those with non-striking postures. Furthermore, the mPFC has been implicated in the attentional allocation and promotes amygdala-dependent aversive conditioning. These findings suggest that the rACC focuses attention on snakes, and promotes aversive conditioning to snakes, which may lead to anxiety and ophidiophobia.

Examination of the Prefrontal Cortex Hemodynamic Responses to the Fist-Edge-Palm Task in Naïve Subjects Using Functional Near-Infrared Spectroscopy

The Fist-Edge-Palm (FEP) task, a manual hand task, has been used to detect frontal dysfunctions in clinical situations: its performance failures are observed in various prefrontal cortex (PFC)-related disorders, including schizophrenia. However, previous imaging studies reported that the performance of the FEP task activated motor-related areas, but not the PFC. Here, we aimed to investigate the relationships between the performance of the FEP task and PFC functions. Hemodynamic activity in the PFC, including the dorsolateral PFC (area 46) and frontal pole (area 10), was recorded. Healthy young subjects performed the FEP task as well as a palm tapping (PT) task (control task) three times. The subjects also completed a Wisconsin Card Sorting Test (WCST) and Schizotypal Personality Scale (STA) questionnaire. We found that hemodynamic activity (Oxy-Hb) in the PFC increased in the first trial of the FEP task but decreased considerably in the second and third trials compared to the PT task. The number of performance errors in the FEP task also decreased in the second and third trials. Error reduction (i.e., learning) in the FEP task between the first and second trials was negatively correlated with schizotypal trait and the number of perseveration errors in the WCST. Furthermore, changes in the PFC hemodynamic activity between the first and second trials were positively correlated with error reduction in the FEP task between the first and second trials, and negatively correlated with the number of perseveration errors in the WCST. These results suggest that learning in the FEP task requires PFC activation, which is negatively associated with perseveration errors in the WCST. The results further suggest that the FEP task, in conjunction with near-infrared spectroscopy, may be useful as a diagnostic method for various disorders with PFC dysfunction.

Performance in a gaze-cueing task is associated with autistic traits

Individuals with autism spectrum disorder (ASD) show impairments in processing social cues such as facial expressions and gaze direction. Several researchers have proposed that autistic traits form a continuum that may be distributed within the general, typically developed, population. Accordingly, several studies have indicated that typically developed individuals with high levels of self-reported autistic traits have autistic-like performance in a variety of paradigms. Here, we designed a gaze-cueing task to examine whether gaze-triggered orienting is related to the extent of typically developed (TD) individuals' autistic traits (determined by their AQ test scores) and whether it is modulated by previous eye contact and different facial expressions. At each trial, TD subjects observed faces with or without eye contact. This facial stimulus then gazed toward the left or right side. Finally, a target appeared on the left or right side of the display and reaction time (RT) to the target was measured. RTs were modulated by congruency between gazing directions and target locations, and by prior eye contact in the congruent trials. In addition, individuals with higher AQ scores were slower at detecting the target when the cue was a happy face. Furthermore, faster RTs in congruent trials were associated with one specific autistic trait (attention switching deficits). Together, these results indicate that autistic traits may influence performance in a gaze cueing task.

Configural Cues Associated with Reward Elicit Theta Oscillations of Rat Retrosplenial Cortical Neurons Phase-Locked to LFP Theta Cycles

Previous behavioral studies implicated the retrosplenial cortex (RSC) in stimulus-stimulus associations, and also in the retrieval of remote associative memory based on EEG theta oscillations. However, neural mechanisms involved in the retrieval of stored information of such associations and memory in the RSC remain unclear. To investigate the neural mechanisms underlying these processes, RSC neurons and local field potentials (LFPs) were simultaneously recorded from well-trained rats performing a cue-reward association task. In the task, simultaneous presentation of two multimodal conditioned stimuli (configural CSs) predicted a reward outcome opposite to that associated with the individual presentation of each elemental CS. Here, we show neurophysiological evidence that the RSC is involved in stimulus-stimulus association where configural CSs are discriminated from each elementary CS that is a constituent of the configural CSs, and that memory retrieval of rewarding CSs is associated with theta oscillation of RSC neurons during CS presentation, which is phase-locked to LFP theta cycles. The results suggest that cue (elementary and configural CSs)-reinforcement associations are stored in the RSC neural circuits, and are retrieved in synchronization with LFP theta rhythm.

Post-procedural high platelet reactivity with prasugrel loading predicts in-hospital adverse events in ACS patients

Background/Introduction

High platelet reactivity (HPR) is associated with adverse cardiovascular events, primarily intrastent thrombosis, after a percutaneous coronary intervention (PCI). However, the relationship between hyperacute postprocedural HPR with prasugrel loading and clinical outcomes in acute coronary syndrome (ACS) remains unclear. Moreover, factors contributing to HPR in ACS with prasugrel loading are also unknown.

Purpose

To assess the effects of post-procedural HPR with prasugrel loading on clinical outcomes in ACS during hospitalization, and to define the appropriate cut-off values and identify factors contributing to HPR.

Methods

A single-center, retrospective observational study that enrolled 154 patients who underwent emergent PCI for ACS with prasugrel loading was performed. The P2Y12 reaction unit (PRU) value was measured immediately after PCI using the VerifyNowR system. The primary end-point was major adverse cardiac events (MACE, defined as the composite of death, myocardial infarction, stroke, heart failure, ventricular arrhythmia needing defibrillation).

Results

The mean patient age (standard deviation) was 70.7 (±12.5) years, 76.6% were men, and the average time from the prasugrel intake to PRU calculation was 103.2 (±48.5) min. During the mean hospital stay of 15.6 (±8.5) days, 24 in-hospital MACE (15.5%) and 8 deaths (5.2%) occurred. Thrombosis events, including myocardial infarction recurrence, did not occur (only one case of spontaneous coronary artery dissection was considered as myocardial infarction recurrence). PRU was significantly higher in the MACE group than that in Non-MACE group (287±55 and 232±64, respectively, p<0.001). The ROC curve analysis of PRU for discriminating the significant in-hospital MACE showed the cut-off value of 293 (sensitivity: 62.5%, specificity: 83.1% [AUC=0.756, p<0.0001]). A total of 37 patients (24%) were thus categorized as HPR (PRU>293) immediately after the emergent PCI. Kaplan-Meier curve showing MACE events occurred in the HPR group than that in the non-HPR group (40.5% vs 7.6%, p<0.001). Multiple cox analysis demonstrated that HPR was independent predictors of MACE in patients with ACS who underwent PCI (OR 11.01, 95% CI 2.39–20.2, p<0.0001). Multiple logistic regression model showed old age, female sex, low systolic blood pressure, short prasugrel intake to measure time, and large acute gain were independent predictors of HPR.

Conclusion

PRU was significantly higher in the MACE group, with an appropriate cut-off value of HPR of 293 in this study. HPR was an independent predictor of MACE during hospitalization; however, thrombosis events were not significant. HPR predictors were old age, female sex, low systolic blood pressure, short prasugrel intake to measure time, and large acute gain. This study shows the post-procedural HPR with prasugrel loading in patients with ACS can be a useful predictive marker of adverse events during hospitalization.

Funding Acknowledgement

Type of funding source: None

Cardio-ankle vascular index as an arterial stiffness marker improves on cardiovascular events by adding to framingham risk score

Background

The cardio-ankle vascular index (CAVI) is a non-invasive measurement that evaluates arterial stiffness using the analysis of oscillometric waveform during cuff-Inflation. Several studies reported that CAVI is associated with cardiovascular risk factors, while the clinical prognostic value of CAVI as a surrogate marker of atherosclerosis has not been fully elucidated. Meanwhile, the Framingham risk score (FRS) is an established marker of cardiovascular outcomes.

Purpose

To investigate whether adding CAVI to Framingham risk score improves the prediction of cardiovascular events.

Methods

This prospective observational study included consecutive 422 patients with cardiovascular risk factors but without known coronary artery disease (69±8 years, 63% men). CAVI was measured by the oscillometric method with VaSera vascular screening system. Patients with atrial fibrillation, left ventricular ejection fraction <50%, both ABI<0.9, severe valvular diseases, or hemodialysis were excluded. Primacy outcomes were cardiovascular death, myocardial infarction, stroke, hospitalization for heart failure and revascularization.

Results

During a median follow-up of 3.1 years, cardiovascular events occurred in 12.8% (3.3%, 15.7%, and 19.1% in the low, intermediate and high-risk group of stratification by FRS, respectively). The ROC curve analysis for discriminating cardiovascular events showed that the AUC of CAVI added to Framingham risk score was the highest compared to Framingham risk score and CAVI alone (CAVI added to Framingham risk score: AUC 66.9, 95% CI 59.6–74.2, Framingham risk score alone: AUC 61.5, 95% CI 53.8–69.1, CAVI alone: AUC 62.3, 95% CI 54.1–70.6). The logistic regression analysis demonstrated that CAVI and Framingham risk score were independent predictors of cardiovascular events (CAVI: OR 1.381, 95% CI 1.164–1.597, p=0.004, Framingham risk score: OR 1.135, 95% CI 1.044–1.225, p=0.007). Next, when logistic regression analysis was performed simultaneously on Framingham risk factor and CAVI, CAVI was an independent predictor of cardiovascular events (OR 1.347, 95% CI 1.124–1.569, p=0.009). Furthermore, in the likelihood ratio test, CAVI added to Framingham risk score significantly improved the cardiovascular event prediction ability than Framingham risk factor alone. Next, when patients with intermediate risk (n=217) were divided into two groups based on CAVI of 9.0, the Kaplan-Meier estimate showed that events occurred more frequently in higher CAVI group (9.3% and 29.1%, log-rank, P=0.009) and the C-statistic was 0.662. Multiple Cox analysis showed that, in the intermediate risk group, CAVI was an independent predictor of primary outcomes (HR 1.387 per 1 index, 95% CI 1.081–1.779, p=0.010).

Conclusion

The measurement of CAVI could be a useful predictor for cardiovascular events. In addition, the combination of CAVI and Framingham risk score could improve the predictability compared to the Framingham risk score alone.

Funding Acknowledgement

Type of funding source: None

Development of assembled microchannel resonator as an alternative fabrication method of a microchannel resonator for mass sensing in flowing liquid

We propose an alternate fabrication technique of microchannel resonators based on an assembly method of three separate parts to form a microchannel resonator on a chip. The capability of the assembled microchannel resonator to detect mass is confirmed by injecting two liquids with different densities. The experimental and theoretical values of the resonator frequency shift are in agreement with each other, which confirms the consistency of the device. The noise level of the device is estimated from the Allan variance plot, so the minimum detectable mass of 230 fg after 16 s of operation is expected. By considering the time of the practical application of 1 ms, it is found that a detectable mass of around 8.51 pg is estimated, which is applicable for detecting flowing microparticles. The sub-pico to a few picogram levels of detection will be applicable for the mass analysis of flowing microparticles such as single cells and will be greatly beneficial for many fields such as chemistry, medicine, biology, and single-cell analysis.

Region-specific brain area reductions and increased cholecystokinin positive neurons in diabetic OLETF rats: implication for anxiety-like behavior

Metabolic disorders can induce psychiatric comorbidities. Both brain and neuronal composition imbalances reportedly induce an anxiety-like phenotype. We hypothesized that alterations of localized brain areas and cholecystokinin (CCK) and parvalbumin (PV) expression could induce anxiety-like behavior in type 2 diabetic Otsuka Long-Evans Tokushima fatty (OLETF) rats. Twenty-week-old OLETF and non-diabetic Long-Evans Tokushima Otsuka (LETO) rats were used. The areas of corticolimbic regions were smaller in OLETF rats. The densities of CCK positive neurons in the lateral and basolateral amygdala, hippocampal cornu ammonis area 2, and prelimbic cortex were higher in OLETF rats. The densities of PV positive neurons were comparable between OLETF and LETO rats. Locomotion in the center zone in the open field test was lower in OLETF rats. These results suggest that imbalances of specific brain region areas and neuronal compositions in emotion-related areas increase the prevalence of anxiety-like behaviors in OLETF rats.

Rat Paraventricular Neurons Encode Predictive and Incentive Information of Reward Cues

The paraventricular nucleus of the thalamus (PVT) has been implicated in cue-induced motivated behaviors. Although reward-associated cues (conditioned stimuli, CSs) contain different types of information including predictive information of future reward delivery and incentive (motivational) value of the reward, it remains unknown whether PVT neurons represent predictive and incentive information of CSs. It is suggested that neural activity just after the onset of CSs (early activity) and that just before reward delivery (late activity) might more strongly represent predictive and incentive information, respectively. In this study, rats were trained to lick a tube, which was protruded close to their mouth just after a CS, to obtain a reward (sucrose or water) (cue-induced licking task). Auditory and visual CSs were used: each elemental cue (CS) predicted reward or non-reward outcome, while simultaneous presentation of the two elemental cues (configural cues) predicted the opposite reward outcome. We recorded PVT neurons in the cue-induced licking task, and report that half of the CS-responsive PVT neurons responded selectively to the CSs predicting reward outcome regardless of physical property of the cues (CS+-selective). In addition, the early activity of the CS+-selective neurons discriminated reward/non-reward association (predictive information) and was less sensitive to reward value and motivation reflected by lick latency (incentive information), while the late activity of the CS+-selective neurons was correlated with reward value and motivation rather than reward/non-reward association. Early and late population activity of the CS+-selective neurons also represented predictive and incentive information of the CSs, respectively. On the other hand, activity of more than half of the PVT neurons was correlated with individual licking during licking to acquire reward. Taken together, the results suggest that the PVT neurons engage in different neural processes involved in cue-induced motivated behaviors: CS encoding to determine reward availability and form motivation for reward-seeking behavior, and hedonic mouth movements during reward consumption.

0757 Increasing Number of Cases Who Had Both Hypersomnolence Disorders and Developmental Disorders With Orexin Measurements

Introduction

Recently, attention has been paid to the relationship between developmental disorders such as attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD), and sleep disorders. We meet many developmental disorder patients who complaint hypersomnolence. Among these patients, cases with coexistence of central hypersomnia and developmental disorders, or developmental disorder alone were increased. Therefore, we first investigated patients with the complaint of hypersomnolence, who were also suspected developmental disorders. Furthermore, we have been measuring CSF orexin in 17 cases suspected of both disorders to investigate orexin levels of these patients.

Methods

86patients who complained of EDS with suspicion of developmental disorders had been examined. In order to diagnose hypersomnolence disorders, PSG and MSLT were performed. Psychological examinations were performed for diagnosing developmental disorders.We have been measuring for CSF orexin in 17 cases suspected both hypersomnolence and developmental disorders. We examined the onset of hypersomnolence and the clinical history of these ADHD or ASD cases for more details.

Results

In 86 examined cases, developmental disorders coexisted in 30 cases. Among 30 cases, ADHD were 18, ASD were 6 and both diagnosed were 6 cases. Among them, 20 cases diagnosed as having coexistence of hypersomnia (8: narcolepsy, 12: IHS) and developmental disorders (ADHD:12, ASD:4, ADHD/ASD:4). In 17 cases with orexin measurements, 10 cases coexisted ADHD and 4 cases coexisted ASD. Two cases diagnosed as both ADHD and ASD. In 10 ADHD cases, 3 cases had low orexin levels, and 7 cases had normal orexin levels. Other 7 ASD cases had normal orexin levels.

Conclusion

ADHD has a higher rate of central hypersomnia (12/18) compared with ASD and the rate of narcolepsy was also high (5/12). While patients in ASD was diagnosed as IHS (3/6), narcolepsy cases were not observed. It became clear that the majority of patients had developmental disorder or had a tendency for developmental disorder before the onset of hypersomnolence.Although it is possible that ADHD/ASD symptoms may be exacerbated by orexin dysfunctions, ADHD/ASD may not newly occur. There were cases with low orexin levels, but it seems that narcolepsy happened to coexist with developmental disorders.

Support

a

A Prototypical Template for Rapid Face Detection Is Embedded in the Monkey Superior Colliculus

Human babies respond preferentially to faces or face-like images. It has been proposed that an innate and rapid face detection system is present at birth before the cortical visual pathway is developed in many species, including primates. However, in primates, the visual area responsible for this process is yet to be unraveled. We hypothesized that the superior colliculus (SC) that receives direct and indirect retinal visual inputs may serve as an innate rapid face-detection system in primates. To test this hypothesis, we examined the responsiveness of monkey SC neurons to first-order information of faces required for face detection (basic spatial layout of facial features including eyes, nose, and mouth), by analyzing neuronal responses to line drawing images of: (1) face-like patterns with contours and properly placed facial features; (2) non-face patterns including face contours only; and (3) nonface random patterns with contours and randomly placed face features. Here, we show that SC neurons respond stronger and faster to upright and inverted face-like patterns compared to the responses to nonface patterns, regardless of contrast polarity and contour shapes. Furthermore, SC neurons with central receptive fields (RFs) were more selective to face-like patterns. In addition, the population activity of SC neurons with central RFs can discriminate face-like patterns from nonface patterns as early as 50 ms after the stimulus onset. Our results provide strong neurophysiological evidence for the involvement of the primate SC in face detection and suggest the existence of a broadly tuned template for face detection in the subcortical visual pathway.

Distinct effects of thermal treatments after lengthening contraction on mechanical hyperalgesia and exercise-induced physiological changes in rat muscle

Delayed-onset muscle soreness (DOMS) is a common but displeasing event induced by excessive muscle use or unaccustomed exercise and characterized by tenderness and movement-related pain in the exercised muscle. Thermal therapies, either icing or heating applied to muscles immediately after exercise, have been used as therapeutic interventions for DOMS. However, the mechanisms of their analgesic effects, and physiological and metabolic changes in the muscle during thermal therapy, remain unclear. In the present study, we investigated the effects of both thermal treatments on mechanical hyperalgesia of DOMS and physiological and muscle metabolite changes using the rat DOMS model induced by lengthening contraction (LC) to the gastrocnemius muscle. Heating treatment just after LC induced analgesic effects, while rats with icing treatment showed mechanical hyperalgesia similar to that of the LC group. Furthermore, increased physiological responses (e.g., muscle temperature and blood flow) following the LC were significantly kept high only in the rats with heating treatment. In addition, heating treatment increased metabolites involved in the improvement of blood flow and oxidative metabolisms in the exercised muscle. The results indicated that heating treatment just after LC has analgesic effects on DOMS, which might be mediated partly through the improvement of muscle oxidative metabolisms by changes in metabolites and elevated physiological responses.NEW & NOTEWORTHY Physiological effects of thermal therapy in the muscle and its mechanisms of analgesic effects remain unclear. The results indicated that heating, but not icing, treatment just after lengthening contractions induced analgesic effects in the rat muscle. Increases in hemodynamics, muscle temperature, and metabolites such as nicotinamide were more prominent in heating treatment, consistent with improvement of muscle oxidative metabolisms, which might reduce chemical factors to induce mechanical hyperalgesia.

Motor Imagery Training With Neurofeedback From the Frontal Pole Facilitated Sensorimotor Cortical Activity and Improved Hand Dexterity

To develop a real-time neurofeedback system from the anterior prefrontal cortex (aPFC) using functional near-infrared spectroscopy (fNIRS) for motor rehabilitation, we investigated the effects of motor imagery training with neurofeedback from the aPFC on hand dexterity and cerebral hemodynamic activity during a motor rehabilitation task. Thirty-one right-handed healthy subjects participated in this study. They received motor imagery training six times for 2 weeks under fNIRS neurofeedback from the aPFC, in which they were instructed to increase aPFC activity. The real group subjects (n = 16) were shown real fNIRS neurofeedback signals from the aPFC, whereas the sham group subjects (n = 15) were shown irrelevant randomized signals during neurofeedback training. Before and after the training, hand dexterity was assessed by a motor rehabilitation task, during which cerebral hemodynamic activity was also measured. The results indicated that aPFC activity was increased during the training, and performance improvement rates in the rehabilitation task after the training was increased in the real group when compared with the sham group. Improvement rates of mean aPFC activity across the training were positively correlated with performance improvement rates in the motor rehabilitation task. During the motor rehabilitation task after the training, the hemodynamic activity in the left somatosensory motor-related areas [premotor area (PM), primary motor area (M1), and primary somatosensory area (S1)] was increased in the real group, whereas the hemodynamic activity was increased in the supplementary motor area in the sham group. This hemodynamic activity increases in the somatosensory motor-related areas after the training correlated with aPFC activity during the last 2 days of motor imagery training. Furthermore, improvement rates of M1 hemodynamic activity after the training was positively correlated with performance improvement rates in the motor rehabilitation task. The results suggest that the aPFC might shape activity in the somatosensory motor-related areas to improve hand dexterity. These findings further suggest that the motor imagery training using neurofeedback signals from the aPFC might be useful to patients with motor disability.

Hyperbaric Normoxia Improved Glucose Metabolism and Decreased Inflammation in Obese Diabetic Rat

Hyperbaric treatment improves hyperglycemia and hyperinsulinemia in type 2 diabetes associated with obesity. However, its mode of action is unknown. The purpose of the present study was to investigate the influences of regular hyperbaric treatment with normal air at 1.3 atmospheres absolute (ATA) on glucose tolerance in type 2 diabetes with obesity. The focus was directed on inflammatory cytokines in the adipose tissue and skeletal muscle. Otsuka Long-Evans Tokushima Fatty (OLETF) rats were used as models of type 2 diabetes with obesity and Long-Evans Tokushima Otsuka (LETO) rats served as healthy controls. The rats were randomly assigned to untreated or hyperbaric treatment groups exposed to 1.3 ATA for 8 h d-1 and 5 d wk-1 for 16 wks. Glucose levels were significantly higher in the diabetic than in the healthy control rats. Nevertheless, glucose levels at 30 and 60 min after glucose administration were significantly lower in the diabetic rats treated with 1.3 ATA than in the untreated diabetic rats. Insulin levels at fasting and 120 min after glucose administration were significantly lower in the diabetic rats treated with 1.3 ATA than in the untreated diabetic rats. Hyperbaric treatment also increased interleukin-10 (IL-10) expression in the skeletal muscle and decreased tumor necrosis factor α (TNFα) expression in adipose tissue. These results suggested that TNFα downregulation and IL-10 upregulation in diabetic rats subjected to hyperbaric treatment participate in the crosstalk between the adipose and skeletal muscle tissues and improve glucose intolerance.

Analgesic Effects of Compression at Trigger Points Are Associated With Reduction of Frontal Polar Cortical Activity as Well as Functional Connectivity Between the Frontal Polar Area and Insula in Patients With Chronic Low Back Pain: A Randomized Trial

Background

Compression of myofascial trigger points (MTrPs) in muscles is reported to reduce chronic musculoskeletal pain. Although the prefrontal cortex (PFC) is implicated in development of chronic pain, the mechanisms of how MTrP compression at low back regions affects PFC activity remain under debate. In this study, we investigated effects of MTrP compression on brain hemodynamics and EEG oscillation in subjects with chronic low back pain.

Methods

The study was a prospective, randomized, parallel-group trial and an observer and subject-blinded clinical trial. Thirty-two subjects with chronic low back pain were divided into two groups: subjects with compression at MTrPs (n = 16) or those with non-MTrPs (n = 16). Compression at MTrP or non-MTrP for 30 s was applied five times, and hemodynamic activity (near-infrared spectroscopy; NIRS) and EEGs were simultaneously recorded during the experiment.

Results

The results indicated that compression at MTrPs significantly (1) reduced subjective pain (P < 0.05) and increased the pressure pain threshold (P < 0.05), (2) decreased the NIRS hemodynamic activity in the frontal polar area (pPFC) (P < 0.05), and (3) increased the current source density (CSD) of EEG theta oscillation in the anterior part of the PFC (P < 0.05). CSD of EEG theta oscillation was negatively correlated with NIRS hemodynamic activity in the pPFC (P < 0.05). Furthermore, functional connectivity in theta bands between the medial pPFC and insula cortex was significantly decreased in the MTrP group (P < 0.05). The functional connectivity between those regions was positively correlated with subjective low back pain (P < 0.05).

Discussion

The results suggest that MTrP compression at the lumbar muscle modulates pPFC activity and functional connectivity between the pPFC and insula, which may relieve chronic musculoskeletal pain.

Trial registration

This trial was registered at University Hospital Medical Information Network Clinical Trials Registry (UMIN000033913) on 27 August 2018, at https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000038660.

P4634Acute-phase high platelet reactivity with prasugrel loading is correlated with clinical outcomes during hospitalization in acute coronary syndrome

Background/Introduction

Although high platelet reactivity (HPR) seems to be associated with adverse cardiovascular events after percutaneous coronary intervention (PCI), the relationship between post-procedure HPR with prasugrel loading and clinical outcomes in acute coronary syndrome (ACS) is still unclear. Moreover, factors contributing to HPR in ACS with prasugrel loading are also unknown.

Purpose

This study aimed to assess the impact of post-procedure HPR with prasugrel loading on clinical outcomes in ACS during hospitalization, as well as to define appropriate cut-off values and identify factors contributing to HPR.

Methods

We performed a single-centre, retrospective observational study that enrolled 132 patients who underwent emergent PCI for ACS with prasugrel loading. The P2Y12 reaction unit (PRU) value was measured immediately after PCI with the VerifyNowR System. The primary endpoint was major adverse cardiac events (MACE, defined as the composite of death, myocardial infarction, stroke, heart failure, ventricular arrhythmia needing defibrillation).

Results

Mean patient age (standard deviation) was 70.7 (±12.5) years, 76% were male, and average time from prasugrel intake to PRU calculation was 101 (±48.8) min. During a mean hospital stay of 15.4 (±8.0) days, there were 22 (16%) MACE events and 6 (4%) deaths. The post-procedure PRU value was 241±66. HPR was significantly higher in MACE group than non-MACE group [287 (±55) vs 232 (±64), p<0.001]. The ROC curve analysis of PRU for discriminating significant in-hospital MACE showed a cut off value of 293 (sensitivity: 64%, specificity: 84% [AUC=0.764, p<0.0001]). Thus, 33 patients (25%) were found to have HPR (PRU>293) immediately after emergent PCI. Kaplan-Meier curve analysis showed MACE events occurred more frequently in the HPR group than in the non-HPR group (42% vs 8%, log rank p<0.001). Multiple Cox regression analysis showed that peak creatine phosphokinase >3,000 U/L and HPR were independent predictors of MACE in patients with ACS who underwent PCI (OR 4.96, 95% CI 1.86–13.26, p=0.001, and OR 7.52, 95% CI 2.73–20.7, p<0.0001, respectively). HPR was significantly correlated with age, female sex, and reference lumen short diameter (pre-dilation) used in PCI.

Conclusion

HPR was significantly associated with adverse event during hospitalization in ACS patients. Female patients with large culprit lesion diameter were more likely to have HPR. Appropriate cut-off value of HPR in this study was 293. HPR in early-phase of ACS with prasugrel loading is a useful predictor of adverse events during hospitalization.

Neural Representation of Overlapping Path Segments and Reward Acquisitions in the Monkey Hippocampus

Disambiguation of overlapping events is thought to be the hallmark of episodic memory. Recent rodent studies have reported that when navigating overlapping path segments in the different routes place cell activity in the same overlapping path segments were remapped according to different goal locations in different routes. However, it is unknown how hippocampal neurons disambiguate reward delivery in overlapping path segments in different routes. In the present study, we recorded monkey hippocampal neurons during performance of three virtual navigation (VN) tasks in which a monkey alternately navigated two different routes that included overlapping path segments (common central hallway) and acquired rewards in the same locations in overlapping path segments by manipulating a joystick. The results indicated that out of 106 hippocampal neurons, 57 displayed place-related activity (place-related neurons), and 18 neurons showed route-dependent activity in the overlapping path segments, consistent with a hippocampal role in the disambiguation of overlapping path segments. Moreover, 75 neurons showed neural correlates to reward delivery (reward-related neurons), whereas 56 of these 75 reward-related neurons showed route-dependent reward-related activity in the overlapping path segments. The ensemble activity of reward-related neurons represented reward delivery, locations, and routes in the overlapping path segments. In addition, ensemble activity patterns of hippocampal neurons more distinctly represented overlapping path segments than non-overlapping path segments. The present results provide neurophysiological evidence of disambiguation in the monkey hippocampus, consistent with a hippocampal role in episodic memory, and support a recent computational model of "neural differentiation," in which overlapping items are better represented by repeated retrieval with competitive learning.

Superior Neuronal Detection of Snakes and Conspecific Faces in the Macaque Medial Prefrontal Cortex

Snakes and conspecific faces are quickly and efficiently detected in primates. Because the medial prefrontal cortex (mPFC) has been implicated in attentional allocation to biologically relevant stimuli, we hypothesized that it might also be highly responsive to snakes and conspecific faces. In this study, neuronal responses in the monkey mPFC were recorded, while monkeys discriminated 8 categories of visual stimuli. Here, we show that the monkey mPFC neuronal responses to snakes and conspecific faces were unique. First, the ratios of the neurons that responded strongly to snakes and monkey faces were greater than those of the neurons that responded strongly to the other stimuli. Second, mPFC neurons responded stronger and faster to snakes and monkey faces than the other categories of stimuli. Third, neuronal responses to snakes were unaffected by low-pass filtering of the images. Finally, activity patterns of responsive mPFC neurons discriminated snakes from the other stimuli in the second 50 ms period and monkey faces in the third period after stimulus onset. These response features indicate that the mPFC processes fast and coarse visual information of snakes and monkey faces, and support the hypothesis that snakes and social environments have shaped the primate visual system over evolutionary time.

Fungal Planet description sheets: 868-950

Novel species of fungi described in this study include those from various countries as follows: Australia, Chaetomella pseudocircinoseta and Coniella pseudodiospyri on Eucalyptus microcorys leaves, Cladophialophora eucalypti, Teratosphaeria dunnii and Vermiculariopsiella dunnii on Eucalyptus dunnii leaves, Cylindrium grande and Hypsotheca eucalyptorum on Eucalyptus grandis leaves, Elsinoe salignae on Eucalyptus saligna leaves, Marasmius lebeliae on litter of regenerating subtropical rainforest, Phialoseptomonium eucalypti (incl. Phialoseptomonium gen. nov.) on Eucalyptus grandis × camaldulensis leaves, Phlogicylindrium pawpawense on Eucalyptus tereticornis leaves, Phyllosticta longicauda as an endophyte from healthy Eustrephus latifolius leaves, Pseudosydowia eucalyptorum on Eucalyptus sp. leaves, Saitozyma wallum on Banksia aemula leaves, Teratosphaeria henryi on Corymbia henryi leaves. Brazil, Aspergillus bezerrae, Backusella azygospora, Mariannaea terricola and Talaromyces pernambucoensis from soil, Calonectria matogrossensis on Eucalyptus urophylla leaves, Calvatia brasiliensis on soil, Carcinomyces nordestinensis on Bromelia antiacantha leaves, Dendryphiella stromaticola on small branches of an unidentified plant, Nigrospora brasiliensis on Nopalea cochenillifera leaves, Penicillium alagoense as a leaf endophyte on a Miconia sp., Podosordaria nigrobrunnea on dung, Spegazzinia bromeliacearum as a leaf endophyte on Tilandsia catimbauensis, Xylobolus brasiliensis on decaying wood. Bulgaria, Kazachstania molopis from the gut of the beetle Molops piceus. Croatia, Mollisia endocrystallina from a fallen decorticated Picea abies tree trunk. Ecuador, Hygrocybe rodomaculata on soil. Hungary, Alfoldia vorosii (incl. Alfoldia gen. nov.) from Juniperus communis roots, Kiskunsagia ubrizsyi (incl. Kiskunsagia gen. nov.) from Fumana procumbens roots. India, Aureobasidium tremulum as laboratory contaminant, Leucosporidium himalayensis and Naganishia indica from windblown dust on glaciers. Italy, Neodevriesia cycadicola on Cycas sp. leaves, Pseudocercospora pseudomyrticola on Myrtus communis leaves, Ramularia pistaciae on Pistacia lentiscus leaves, Neognomoniopsis quercina (incl. Neognomoniopsis gen. nov.) on Quercus ilex leaves. Japan, Diaporthe fructicola on Passiflora edulis × P. edulis f. flavicarpa fruit, Entoloma nipponicum on leaf litter in a mixed Cryptomeria japonica and Acer spp. forest. Macedonia, Astraeus macedonicus on soil. Malaysia, Fusicladium eucalyptigenum on Eucalyptus sp. twigs, Neoacrodontiella eucalypti (incl. Neoacrodontiella gen. nov.) on Eucalyptus urophylla leaves. Mozambique, Meliola gorongosensis on dead Philenoptera violacea leaflets. Nepal, Coniochaeta dendrobiicola from Dendriobium lognicornu roots. New Zealand, Neodevriesia sexualis and Thozetella neonivea on Archontophoenix cunninghamiana leaves. Norway, Calophoma sandfjordenica from a piece of board on a rocky shoreline, Clavaria parvispora on soil, Didymella finnmarkica from a piece of Pinus sylvestris driftwood. Poland, Sugiyamaella trypani from soil. Portugal, Colletotrichum feijoicola from Acca sellowiana. Russia, Crepidotus tobolensis on Populus tremula debris, Entoloma ekaterinae, Entoloma erhardii and Suillus gastroflavus on soil, Nakazawaea ambrosiae from the galleries of Ips typographus under the bark of Picea abies. Slovenia, Pluteus ludwigii on twigs of broadleaved trees. South Africa, Anungitiomyces stellenboschiensis (incl. Anungitiomyces gen. nov.) and Niesslia stellenboschiana on Eucalyptus sp. leaves, Beltraniella pseudoportoricensis on Podocarpus falcatus leaf litter, Corynespora encephalarti on Encephalartos sp. leaves, Cytospora pavettae on Pavetta revoluta leaves, Helminthosporium erythrinicola on Erythrina humeana leaves, Helminthosporium syzygii on a Syzygium sp. bark canker, Libertasomyces aloeticus on Aloe sp. leaves, Penicillium lunae from Musa sp. fruit, Phyllosticta lauridiae on Lauridia tetragona leaves, Pseudotruncatella bolusanthi (incl. Pseudotruncatellaceae fam. nov.) and Dactylella bolusanthi on Bolusanthus speciosus leaves. Spain, Apenidiella foetida on submerged plant debris, Inocybe grammatoides on Quercus ilex subsp. ilex forest humus, Ossicaulis salomii on soil, Phialemonium guarroi from soil. Thailand, Pantospora chromolaenae on Chromolaena odorata leaves. Ukraine, Cadophora helianthi from Helianthus annuus stems. USA, Boletus pseudopinophilus on soil under slash pine, Botryotrichum foricae, Penicillium americanum and Penicillium minnesotense from air. Vietnam, Lycoperdon vietnamense on soil. Morphological and culture characteristics are supported by DNA barcodes.

Doublon-holon pairing mechanism via exchange interaction in two-dimensional cuprate Mott insulators

Coupling of charge and spin degrees of freedom is a critical feature of correlated electron oxides, as represented by the spin-related mechanism of a Cooper pair under high-T _c superconductivity. A doublon-holon pair generated on an antiferromagnetic spin background is also predicted to attract each other via the spin-spin interaction J, similar to a Cooper pair, while its evidence is difficult to obtain experimentally. Here, we investigate such an excitonic effect by electroreflectance spectroscopy using terahertz electric field pulses in undoped cuprates: Nd₂CuO₄, Sr₂CuO₂Cl₂, and La₂CuO₄. Analyses of the spectral changes of reflectivity under electric fields reveal that the splitting of odd-parity and even-parity excitons, a measure of doublon-holon binding energy, increases with J. This trend is reproduced by t-J-type model calculations, providing strong evidence of the spin-related doublon-holon pairing. Agreement with the calculations supports the s-wave symmetry of the doublon-holon pair in contrast to the d-wave Cooper pair in doped cuprates.

Pressure-tuning the quantum spin Hamiltonian of the triangular lattice antiferromagnet Cs2CuCl4

Quantum triangular-lattice antiferromagnets are important prototype systems to investigate numerous phenomena of the geometrical frustration in condensed matter. Apart from highly unusual magnetic properties, they possess a rich phase diagram (ranging from an unfrustrated square lattice to a quantum spin liquid), yet to be confirmed experimentally. One major obstacle in this area of research is the lack of materials with appropriate (ideally tuned) magnetic parameters. Using Cs₂CuCl₄ as a model system, we demonstrate an alternative approach, where, instead of the chemical composition, the spin Hamiltonian is altered by hydrostatic pressure. The approach combines high-pressure electron spin resonance and r.f. susceptibility measurements, allowing us not only to quasi-continuously tune the exchange parameters, but also to accurately monitor them. Our experiments indicate a substantial increase of the exchange coupling ratio from 0.3 to 0.42 at a pressure of 1.8 GPa, revealing a number of emergent field-induced phases.

Theoretical studies of quantum magnetism typically assume idealised lattices with freely tunable parameters, which are difficult to realise experimentally. Zvyagin et al. perform challenging measurements at high pressures to tune and to accurately monitor the exchange parameters of a triangular lattice antiferromagnet.

Non-restorative Sleep Caused by Autonomic and Electroencephalography Parameter Dysfunction Leads to Subjective Fatigue at Wake Time in Shift Workers

Sleep is a physiological state that plays important role in the recovery of fatigue. However, the relationship between the physiological status of sleep and subjective fatigue remains unknown. In the present study, we hypothesized that the non-recovery of fatigue at wake time due to non-restorative sleep might be ascribed to changes in specific parameters of electroencephalography (EEG) and heart rate variability (HRV) in poor sleepers. Twenty healthy female shift-working nurses participated in the study. Subjective fatigue was assessed using the visual analog scale (VAS) at bedtime and wake time. During sleep on the night between 2 consecutive day shifts, the EEG powers at the frontal pole, HRV based on electrocardiograms, and distal-proximal gradient of skin temperature were recorded and analyzed. The results indicated that the subjects with high fatigue on the VAS at wake time exhibited (1) a decrease in deep non-rapid eye movement (NREM) (stageN3) sleep duration in the first sleep cycle; (2) a decrease in REM latency; (3) a decrease in ultra-slow and delta EEG powers, particularly from 30 to 65 min after sleep onset; (4) a decrease in the total power of HRV, particularly from 0 to 30 min after sleep onset; (5) an increase in the very low frequency component of HRV; and (6) a smaller increase in the distal-proximal gradient of skin temperature, than those of the subjects with low fatigue levels. The correlational and structural equation modeling analyses of these parameters suggested that an initial decrease in the total power of HRV from 0 to 30 min after sleep onset might inhibit the recovery from fatigue during sleep (i.e., increase the VAS score at wake time) via its effects on the ultra-slow and delta powers from 30 to 65 min after sleep onset, stageN3 duration in the first sleep cycle, REM latency, and distal-proximal gradient of skin temperature. These findings suggest an important role of these physiological factors in recovery from fatigue during sleep, and that interventions to modify these physiological factors might ameliorate fatigue at wake time.

Microwave oscillator using piezoelectric thin-film resonator aiming for ultraminiaturization of atomic clock

We developed a microwave oscillator and a micro electromechanical systems-based rubidium cell for the miniaturization of atomic clocks. A thin-film bulk acoustic resonator (FBAR) having a resonant frequency of the fundamental mode in the 3.5 GHz band was employed instead of a crystal resonator. It delivers a clock transition frequency of Rb atoms of 3.417 GHz without the need for a complicated frequency multiplication using a phase-locked loop. This topology considerably reduces the system scale and power consumption. For downsizing the atomic clock system toward the chip level as well as mass production, a microfabricated gas cell containing Rb and N₂ gases was also developed. These microcomponents were incorporated into an atomic clock test bench, resulting in a clock operation with a short-term frequency instability of 2.1 × 10^-11 at 1 s. To the best of our knowledge, this is the first report of a coherent population trapping clock operation using an FBAR-based microwave oscillator as well as a microfabricated gas cell.