Electrophysiological Responses Research Articles

Two chemosensory proteins in Aleurocanthus spiniferus are involved in the recognition of host VOCs

BackgroundCSPs are known for their complex and arguably obscure function(s), particularly in chemical olfaction. It is unclear which CSPs in Aleurocanthus spiniferus are involved in the identification of host VOCs. This study on A. spiniferus utilized gene expression, ligand binding, RNAi and molecular docking to determine the CSPs involved in the binding and transport of six host VOCs.ResultsFour (AspiCSP7, 9, 12 and 16) of the 12 CSPs underwent transcriptional up- or down-regulation after induction by host VOCs. AspiCSP16 can bind to six VOCs, and AspiCSP7 can bind to five except linalool. dsAspiCSP7-treated adults showed significantly lower tendency to 3-carene, hexanol, (E)-2-hexenal, and lost avoidance of (Z)-3-hexenol; the preference for 3-carene, hexanol, and the avoidance of nonanal and (Z)-3-hexenol were reduced when AspiCSP16 was knocked down. Although it is difficult to convince the results on EAG after silencing 63% of AspiCSP7 and AspiCSP16. dsAspiCSP7 and dsAspiCSP16 treatments reduced the electrophysiological (EAG) response to attractive (3-carene and hexanol), and repellent chemicals [nonanal and (Z)-3-hexenol], which demonstrated the behavioral results. Molecular docking indicated that critical hydrophobic residues, LYS-95 and ILE-59, might be involved in the binding of AspiCSP7 and AspiCSP16 to six host VOCs, respectively.ConclusionsAspiCSP7 and AspiCSP16 are involved in the recognition of host VOCs, including four attractants [(E)-2-hexenal, linalool, 3-carene, hexanol] and two repellents [nonanal and (Z)-3-hexenol]. This study will deepen the understanding of the olfactory mechanisms of host VOCs recognition by A. spiniferus and will support the development of novel compounds and RNA pesticides for controlling pests.Graphical abstract

Effect of childhood epilepsy and antiepileptic drugs on visual evoked potential response and optical coherence tomography

BackgroundEpileptic seizures arise from an excessively synchronous and sustained discharge of a group of neurons. The single feature of all epileptic syndromes is a persistent increase of neuronal excitability. Visual affection in epileptic children could be attributed to the disease itself or the use of anti-epileptic drugs, these changes may involve abnormal electro-physiological response. This biphasic study, conducted at the neuro-pediatric clinic at neurology department, aimed to investigate effect of idiopathic childhood epilepsy per se on (1) visual evoked potential and (2) optical coherence tomography and effect of selected two antiepileptic medications on them. All subjects were exposed to visual evoked potential and only cooperative subjects exposed to ocular coherence tomography before and after anti-epileptic drugs and were followed up over 2 years.ResultsThe study included 50 newly diagnosed epileptic children and 50 healthy controls, the mean P100 latency in the right eyes of the control group was 110.4 ± 3.76ms, while in the patients group was 114.94 ± 12.81ms that showed significant difference between the two groups with p value (0.020). After 2 years of treatment by levetiracetam and valproate, the mean P100 latency of the right and left eyes in the valproate group was 112.34 ± 7.05 ms and 112.59 ± 5.2 ms, respectively, and it was 114.85 ± 10.39 ms and 116.14 ± 9.84 ms, respectively, in the valproate group, which showed insignificant difference between the two groups. The mean average of retinal nerve fiber layer thickness between patients and controls was significant in both right and left eyes with p value 0.002 and < 0.001, respectively. After 1 year of treatment by levetiracetam in the first group and valproate in the second group, there was no significant difference between the two groups neither regarding retinal nerve fiber layer thickness nor ganglion cell complex in both eyes.ConclusionsThere was prolonged latency in the epileptic children before starting anti-epileptic drugs more than the control group; also there was thinning of the retinal nerve fiber layer thickness and average part of the ganglion cell complex thickness more in the epileptic children than in the healthy controls.

Examining the Effects of Brief Mindfulness on Psychophysiological Responses and Performance in Self-Competitive Tasks

Mindfulness practice has been recognized as an effective method for reducing stress, enhancing self-awareness, and improving overall well-being, influencing various cognitive processes such as attention and self-control. While extensive research has focused on long-term mindfulness programs, recent years have seen the emergence of brief mindfulness practices. This study aims to investigate the effects of brief mindfulness on electrophysiological responses, and performance in a self-competitive context. A total of 52 participants were divided into two groups for the experiment. They were randomly assigned to one of two experimental conditions: a brief mindfulness practice (n = 29) or a control intervention (n = 23), each lasting 10 min. Initially, participants completed a cognitive task (Tower of Hanoi—ToH), followed by their respective intervention. Participants then performed the ToH task again, with encouragement to exceed their previous performance. Measures were taken for performance metrics and psychophysiological responses—including electrodermal response (EDA) and cardiovascular parameters. The results indicated that a brief mindfulness significantly enhanced performance (p &lt; 0.05), increased self-efficacy (including self-confidence and perceived task importance) prior to the ToH task, and reduced the perceived difficulty of the task upon completion. Moreover, an increase in EDA was found in the brief mindfulness group. However, no significant changes in the measured cardiovascular responses were observed. These findings suggest that brief mindfulness can effectively improve cognitive task performance by enhancing self-efficacy and reshaping task perception.

Sympathetic motor neuron dysfunction is a missing link in age-associated sympathetic overactivity

Overactivity of the sympathetic nervous system is a hallmark of aging. The cellular mechanisms behind this overactivity remain poorly understood, with most attention paid to likely central nervous system components. In this work, we hypothesized that aging also affects the function of motor neurons in the peripheral sympathetic ganglia. To test this hypothesis, we compared the electrophysiological responses and ion-channel activity of neurons isolated from the superior cervical ganglia of young (12 weeks), middle-aged (64 weeks), and old (115 weeks) mice. These approaches showed that aging does impact the intrinsic properties of sympathetic motor neurons, increasing spontaneous and evoked firing responses. A reduction of M current emerged as a major contributor to age-related hyperexcitability. Thus, it is essential to consider the effect of aging on motor components of the sympathetic reflex as a crucial part of the mechanism involved in sympathetic overactivity.

Sympathetic motor neuron dysfunction is a missing link in age-associated sympathetic overactivity.

Overactivity of the sympathetic nervous system is a hallmark of aging. The cellular mechanisms behind this overactivity remain poorly understood, with most attention paid to likely central nervous system components. In this work, we hypothesized that aging also affects the function of motor neurons in the peripheral sympathetic ganglia. To test this hypothesis, we compared the electrophysiological responses and ion-channel activity of neurons isolated from the superior cervical ganglia of young (12 weeks), middle-aged (64 weeks), and old (115 weeks) mice. These approaches showed that aging does impact the intrinsic properties of sympathetic motor neurons, increasing spontaneous and evoked firing responses. A reduction of M current emerged as a major contributor to age-related hyperexcitability. Thus, it is essential to consider the effect of aging on motor components of the sympathetic reflex as a crucial part of the mechanism involved in sympathetic overactivity.

Matthew 7:3-a response to Kingsland and Taiz (2024).

I present here a rebuttal to an article in this volume wherein Kingsland and Taiz (2024) cast aspersions about an article I have written concerning Sir Jagadis Chandra Bose (Minorsky PV, in Plant Signal Behav 16:1818030, 2021) a brilliant Bengali scientist who was a pioneer not only in physics (microwaves and semi-conductors), but also in elucidating the electrophysiological responses of plants to environmental stimuli. The charge of racism that I have levelled at Bose's most powerful and well-connected botanical adversary in the 1920s, Daniel T. MacDougal, is irrefutable: MacDougal was a racist, his racism extended to South Asians, and he used racist epithets in referring to Bose. MacDougal offered no cogent arguments against Bose's electrophysiological measurements but attacked Bose with the racist trope that South Asians were "mystics." MacDougal wielded his political and editorial clout to publicize faulty research in opposition to Bose while ignoring a sizable body of contemporaneous evidence in support of Bose's ideas. Unfortunately, given MacDougal's stature as the General Secretary of the American Association for the Advancement of Science (AAAS) and the racist tenor of the time, many Western scientists were too ready to accept uncritically MacDougal's proclamations that Bose was a fraud, an incompetent, and a "Hindoo" mystic. Bose was one of the greatest minds to ever contemplate plant function. It is high time that we, in the West, redress this historical wrong, and acknowledge Bose's enormous and revolutionary contributions to plant physiology.

Electrophysiology in ophthalmology

Electrophysiological examinations are used in ophthalmology to determine the functionality of the neurons of the visual pathway. As electrophysiological examinations are independent of the subjective perception and response of the patient, they are considered to be objective functional diagnostics of vision. Electroretinography (ERG) is used to examine the retina (especially the photoreceptors), electro-oculography (EOG) is used to examine the functionality of the retinal pigment epithelium and visually evoked potentials (VEP) are used to evaluate the integrity of the entire visual pathway. Abnormalities in electrophysiological responses should always be interpreted in the context of other functional and morphological findings.

Female contact sex pheromone recognition in the German cockroach (Blattella germanica) is mediated by two male antennae-enriched sensory neuron membrane proteins.

The German cockroach Blattella germanica is a notorious urban health pest that has developed resistance to multiple pesticides. Thus, novel non-lethal pest control agents are urgently needed. Olfaction interference via disruption of sex pheromone recognition-related genes offers a promising approach. The German cockroach has a unique courtship behavior in which female adults emit contact sex pheromones (CSPs) in response to antennal touching, which subsequently triggers distinctive male sex behavioral responses. Due to the limited volatility of CSPs, the molecular mechanisms underlying their recognition and the specific olfactory pathways activated remain poorly defined. Although the odorant receptor coreceptor (Orco) is critical for most insect olfaction, sensory neuron membrane proteins (SNMPs), in particular SNMP1, also play crucial roles in sex pheromone recognition in moths and flies. While multiple SNMP1 homologs have been identified in multiple insect species, they have yet to be fully functionally characterized in cockroaches. In this study, RNA-interference (RNAi)-mediated knockdown of BgerOrco reduced both the electrophysiology responses and courtship behaviors of males, indicating CSP perception proceeds via an olfaction pathway. Similar RNAi knockdown of BgerSNMP1e and BgerSNMP1d, which are predominantly expressed in male antennae, revealed critical roles in perceiving the major component of the Blattella germanica CSP blend. Unlike BgerSNMP1e, BgerSNMP1d was also found to function in the perception of the minor CSP component. Molecular docking analyses revealed no differences in the binding affinities of BgerSNMP1d for the major and minor CSP components, whereas the binding affinities of BgerSNMP1e displayed clear selectivity for the major component. Our results show that the olfactory pathway is critical for CSP recognition and that two male-enriched SNMP genes, BgerSNMP1e and BgerSNMP1d, are crucial factors mediating the male response to CSP stimulation in German cockroaches. This study lays a foundation for studying the mechanisms of CSP recognition and provides novel molecular targets with potential to be exploited as disruptors of courtship behavior. © 2024 Society of Chemical Industry.

Identifying Multiomic Signatures of X-Linked Retinoschisis-Derived Retinal Organoids and Mice Harboring Patient-Specific Mutation Using Spatiotemporal Single-Cell Transcriptomics.

X-linked retinoschisis (XLRS) is an inherited retinal disorder with severe retinoschisis and visual impairments. Multiomics approaches integrate single-cell RNA-sequencing (scRNA-seq) and spatiotemporal transcriptomics (ST) offering potential for dissecting transcriptional networks and revealing cell-cell interactions involved in biomolecular pathomechanisms. Herein, a multimodal approach is demonstrated combining high-throughput scRNA-seq and ST to elucidate XLRS-specific transcriptomic signatures in two XLRS-like models with retinal splitting phenotypes, including genetically engineered (Rs1emR209C) mice and patient-derived retinal organoids harboring the same patient-specific p.R209C mutation. Through multiomics transcriptomic analysis, the endoplasmic reticulum (ER) stress/eukryotic initiation factor 2 (eIF2) signaling, mTOR pathway, and the regulation of eIF4 and p70S6K pathways are identified as chronically enriched and highly conserved disease pathways between two XLRS-like models. Western blots and proteomics analysis validate the occurrence of unfolded protein responses, chronic eIF2α signaling activation, and chronic ER stress-induced apoptosis. Furthermore, therapeutic targeting of the chronic ER stress/eIF2α pathway activation synergistically enhances the efficacy of AAV-mediated RS1 gene delivery, ultimately improving bipolar cell integrity, postsynaptic transmission, disorganized retinal architecture, and electrophysiological responses. Collectively, the complex transcriptomic signatures obtained from Rs1emR209C mice and patient-derived retinal organoids using the multiomics approach provide opportunities to unravel potential therapeutic targets for incurable retinal diseases, such as XLRS.

Electrophysiological and olfactory behavioural responses of mature Stilpnotia candida to a mixture of volatiles from Populus×beijingensis

Electrophysiological and olfactory behavioural responses of mature Stilpnotia candida to a mixture of volatiles from Populus×beijingensis

Reward processing dominates the brain during feedback evaluation: Electrophysiological evidence.

During reinforcement learning, people learn based on both positive and negative feedback. Researchers have revealed the reward positivity (RewP) that reflects positive feedback evaluation, however, no electrophysiological indicator has been found to explain negative feedback processing. In reinforcement learning, people would like to expect the positive feedback after a choice, which might explain why previous studies usually found neural responses for reward processing, while the negative feedback processing seems absent. However, no study has designed a task to separate positive and negative feedback processing to measure the corresponding electrophysiological responses. Thus, the present study designed gain processing-advantaged (GA) and loss processing-advantaged (LA) contexts using a modified gambling task to measure specific neural responses to gain processing and loss processing. Electroencephalography (EEG) data were processed using time-domain and time-frequency analyses. The results revealed the RewP and delta oscillation following gain feedback in the GA context, while no negativity or other components specific to loss processing was found, even in the loss condition of LA context. The current results indicate that reward processing dominates the brain during feedback evaluation, whereas loss processing can't be captured by electrophysiological signal.

Diffusive secondary injuries in neuronal networks following a blast impact: A morphological and electrophysiological study using a TBI-on-a-Chip model

Traumatic brain injury (TBI) is a worldwide health issue. Increasing prevalence of blast-induced TBI (bTBI), a predominantly combat-related injury, is an alarming trend necessitating a better understanding of the associated pathogenesis to develop treatments. Further, most bTBI injuries are mild and undiagnosed, permitting secondary biochemical injuries to propagate beyond possible intervention. Unfortunately, few treatment options are available due to a limited understanding of the underlying mechanisms. Additional investigative tools are urgently needed to elucidate the mechanisms behind immediate and long-term bTBI-induced damage. Therefore, we introduce “bTBI-on-a-Chip,” an in vitro blast injury model, capable of simultaneous morphological, biochemical, and bioelectrical assessments before, during, and after blast injury. We show correlated increases in markers of oxidative stress (acrolein) and inflammation (TNF-α) accompanied by electrophysiological deficits post-blast injury. Additionally, we show that these pathological consequences are mitigated by acrolein scavenging. We also show that injury products released by cultures post-injury diffuse through culture media and instigate biochemical injury in uninjured neuronal networks. Furthermore, we show that acrolein, a diffusive component of post-TBI secondary injury, is sufficient to increase inflammation in uninjured cultures. These findings validate bTBI-on-a-Chip as an appropriate model for recapitulating and investigating blast injury in vitro by showing its capabilities of recreating primary and secondary bTBI, monitoring biochemical and electrophysiological responses to injury, and screening possible pharmacological interventions post-injury. We expect that this model could provide insights into the pathological biochemical mechanisms that will be critical in developing future diagnostic and treatment strategies for bTBI patients. Statement of SignificanceThe findings in the current study validate bTBI-on-a-Chip as an appropriate model for recapitulating and investigating blast injury in vitro by demonstrating its capabilities of recreating primary and secondary bTBI, monitoring biochemical and electrophysiological responses to injury, and screening possible pharmacological interventions post-injury. We expect that this model could provide insights into the pathological biochemical mechanisms that will be critical in developing future diagnostic and treatment strategies for bTBI patients.

New insight into the molecular etiopathogenesis of konzo: Cyanate could be a plausible neurotoxin contributing to konzo, contrary to thiocyanate

IntroductionChronic cassava-derived cyanide poisoning is associated with the appearance of konzo, a tropical spastic paraparesis due to selective upper motor neuron damage. Whether the disease is caused by a direct action of cyanide or its metabolites is still an open question. This preliminary study assessed the neurotoxic effects of thiocyanate (SCN) and cyanate (OCN), two cyanide metabolites hypothesized to be plausible toxic agents in konzo. MethodsCultured mouse neuroblastoma (Neuro-2A) and human neuroblastoma (SH-SY5Y) cell lines were incubated (24, 48, and 72hours) in sodium OCN or sodium SCN in a disease-relevant concentration range. Cell viability, caspase (3, 8, and 9) activities, and reactive oxygen species (ROS) generation were evaluated using appropriate assay kits. Additionally, electrophysiological responses induced by OCN and SCN in primary spinal cord neurons (from Sprague Dawley rats) were assessed by whole-cell patch-clamp techniques. ResultsBoth OCN and SCN were toxic in a dose-dependent way, even if SCN toxicity appeared at very high concentrations (30mM, corresponding to more than 100-fold higher than normal plasmatic levels), contrary to OCN (0.3-3mM). OCN was markedly more toxic in a poor culture medium (MEM; IC50 = 3.2mM) compared to a glucose- and amino acid-rich medium (DMEM; IC50=7.6mM). OCN treatment increased the ROS generation by 8.9 folds, as well as the Caspase-3, Caspase-8, and Caspase-9 activities by 3.2, 2.5, and 2.6 folds, respectively. Finally, OCN (and SCN to a lesser extent) induced depolarizing currents in primary spinal cord neurons, through an activation of ionotropic glutamate receptors. ConclusionOur results suggest OCN as the most plausible neurotoxic agent involved in konzo, while SCN toxicity could be questioned at such high concentrations. Also, they support apoptosis, oxidative stress, and excitotoxicity as probable mechanisms of OCN neurotoxicity.

Antennal sensilla of Cyclocephala barrerai (Coleoptera: Melolonthidae): morphology, sexual dimorphism, allometric relationships, and function.

Scarab beetles use pheromones and volatiles to search for their partners and host plants. The perception of these compounds occurs in the beetle antennae, particularly in the sensilla. Relatively few studies have morphologically and physiologically characterized the sensilla of scarab beetles. Cyclocephala barrerai Martínez is a beetle distributed in Mexico. Male beetles have larger antennal lamellae than females, and in both cases, the size of this structure is related to their weight. Previous studies have reported that both sexes are attracted to bacterial volatiles isolated from the female genital chambers. Female cuticular hydrocarbons may act as a sexual contact pheromone. However, antennal sensilla and their electrophysiological responses to behaviorally relevant compounds remain to be investigated. Here, we describe and report the types, allometric relationships, and functions of sensilla found in the lamellae of both C. barrerai sexes. Sensilla were identified, classified, measured, and counted to identify intra and intersexual relationships. The single sensillum recordings showed that plant volatiles, hydrocarbons, and heat stimulated receptor neurons. We identified 2 new types of sensilla basiconica in the scape. Males have more and larger antennal sensilla placodea IV, which specializes in detecting pheromones, plant volatiles, and heat. Females have a greater diversity of sensilla.

Auditory and vestibular function in mitochondrial patients harbouring the m.3243A>G variant.

Hearing impairment is a frequent clinical feature in patients with mitochondrial disease harbouring the pathogenic variant, m.3243A>G. However, auditory neural dysfunction, its perceptual consequences and implications for patient management are not established. Similarly, the association with vestibular impairment has not yet been explored. This case-control study investigated in 12 adults with genetically confirmed m.3243A>G adults [9 females; 45.5 ± 16.3 years (range 18-66); 47.1 ± 21.5 hearing level, dB] compared with 12 age, sex and hearing level-matched controls with sensory (cochlear level) hearing loss [9 females; 46.6 ± 11.8 years (range 23-59); 47.7 ± 25.4 hearing level, dB]. Participants underwent a battery of electroacoustic, electrophysiologic and perceptual tests, which included pure tone audiometry, otoacoustic emissions, auditory brainstem responses, auditory temporal processing measures, monaural/binaural speech perception, balance and vestibular testing and self-reported questionnaires (dizziness and hearing disability). Our findings showed evidence of auditory neural abnormality and perceptual deficits greater than expected for cochlear pathology. Compared with matched controls with sensory hearing loss, adults with mitochondrial disease harbouring m.3243A>G had abnormal electrophysiologic responses from the VIII nerve and auditory brainstem (P = 0.005), an impaired capacity to encode rapidly occurring acoustic signal changes (P = 0.005), a reduced ability to localize sound sources (P = 0.028) and impaired speech perception in background noise (P = 0.008). Additionally, vestibular dysfunction (P = 0.011), greater perceived dizziness (P = 0.001) and reduced stance time (balance, P = 0.009) were also seen in participants with m.3243A>G mitochondrial disease when compared with matched counterparts. This pilot study revealed that auditory evaluation including evoked potential responses from the auditory nerve/brainstem and speech perception in noise tests should form an important part of the management for individuals with m.3243A>G-related mitochondrial disease. Those presenting with hearing impairment and symptoms concerning balance and dizziness should undergo vestibular testing and appropriate management.

Blunted anterior midcingulate response to reward in opioid users is normalized by prefrontal transcranial magnetic stimulation.

Abnormalities in goal-directed behavior, mediated by mesocorticolimbic reward function and structure, contribute to worse clinical outcomes including higher risk of treatment dropout and drug relapse in opioid users (OU). In a sham-controlled randomized study design, we measured whether robot-assisted 10Hz transcranial magnetic stimulation (TMS) applied to the prefrontal cortex was able to modulate anterior midcingulate cortex (MCC) electrophysiological response to rewards, in OU and matched healthy controls. We show that OU exhibit a blunted anterior MCC reward response, compared to healthy controls (t(39) = 2.62, p = 0.01, d = 0.84), and that this is normalized following 10-Hz excitatory TMS (t (36) = .82, p = 0.42, d = 0.17). Excitatory TMS modulated the putative reward function of the MCC in OU. Further work with increased sample sizes and TMS sessions is required to determine whether restoring MCC reward function increases reward-directed behaviors, which may enhance treatment success through the maintenance of treatment goals.

Energy stress induced cardiac autophagy detection via a chronic and dynamic cardiomyocytes-based biosensing platform

Hypoglycemia is a common complication which occurs during the treatment of diabetes, closely associated with cardiovascular events. A sudden decrease in blood glucose increases the risk of arrhythmia, which can lead to sudden cardiac death. This event is usually accompanied by abnormal electrophysiological activities in cardiomyocytes. However, traditional models do not efficiently reflect real-time cardiomyocyte electrophysiological changes under various glucose deprivation conditions in a large-scale and high-throughput manner. Therefore, we need to develop a new biosensing platform to aid in related scientific research. In this study, a cardiomyocyte-based biosensor was developed for real-time, noninvasive monitoring of the electrophysiological responses of cardiomyocytes under different glucose concentrations. The findings show that low-glucose conditions result in abnormal electrophysiology in cardiomyocytes, but autophagy enables cells to survive this adversity. Inhibition of autophagy exacerbates electrophysiological abnormalities, and long-term glucose starvation causes irreversible damage to cardiomyocytes. The proposed chronic and dynamic cardiomyocyte-based biosensing platform provides a new tool for understanding the effects of hypoglycemia on the in vitro cardiomyocyte-based heart model, revealing that autophagy has the potential to be an alternative treatment for diabetes and hypoglycemia.

Brain electrical patterns associated with pleasure and emotion induced by tonal and atonal music.

Several studies in the last 40 years have used electroencephalography (EEG) to recognize patterns of brain electrical activity correlated with emotions evoked by various stimuli. For example, the frontal alpha and theta asymmetry models to distinguish musical emotions and musical pleasure, respectively. Since these studies have used mainly tonal music, in this study, we decided to incorporate both tonal (n = 8) and atonal (n = 8) musical stimuli to observe the subjective and electrophysiological responses associated with valence, arousal, pleasure, and familiarity, from 25 nonmusician Mexican adults (10 females, 15 males; M = 37.8 years old, SD = 15.1). Our results showed that atonal music was perceived as less familiar and pleasurable than tonal music, according to the average subjective ratings. Interestingly, greater right hemispheric activity (alpha suppression) was associated with atonal music listening. Additionally, there was an increase of theta power at the right frontal cortex (F4) correlated with a decrease of pleasure ratings, in line with the frontal theta asymmetry (FTA) model. Finally, according to the model of frontal alpha asymmetry (FAA) to distinguish musical emotions, activation (alpha suppression) of the left frontal cortex (F3) was correlated with greater valence and arousal-that is, joyful music. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Chemical Mechanism of Exogenous Jasmonic Acid-Induced Resistance in Rose Against Spodoptera exigua (Lepidoptera: Noctuidae)1

Abstract Jasmonic acid (JA) plays an important role in the indirect plant-mediated interactions between rose powdery mildew (Podosphaera pannosa [Wallr.: Fr.] de Bary) and Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae) on their shared host Rosa chinensis Jacquin. Bioassays showed that the total number of eggs laid by S. exigua on rose twigs decreased significantly after the twigs were treated with exogenous JA. Gas chromatography coupled with mass spectrometry (GC-MS) showed that the volatile organic chemicals (VOCs) from roses, including alkanes, terpenes, aldehydes, ketones, alcohols, and esters, were significantly changed following treatment with JA. Based on gas chromatography-electroantennographic detection (GC-EAD) and GC-MS analysis, the electrophysiological responses of S. exigua moths could be elicited by 8 compounds from the JA-induced roses, including 3-carene, 1-dodecanol, methyl stearate, 1-tetradecanol, hexadecane, eucalyptol, β-myrcene, and 1-iodododecane. Among these chemicals, the first 6 exhibited significant repellent activity to ovipositional behaviors of the gravid moths, while the latter 2 were attractive. The inhibition index of methyl stearate at a concentration of 15 mg/ml reached 65.12%. On the other hand, the quantity of the first 6 chemicals increased significantly and the latter two decreased due to the JA induction. These results reveal a new mechanism for resistance in rose plants against S. exigua. After JA induction, the rose plants appear to up-regulate the biosynthesis of the chemicals with repellent activities against S. exigua and, in the meantime, down-regulate the attractant chemicals.

The modulation of reward expectancy on the processing of near-miss outcomes: An ERP study

A near-miss is a situation in which a gambler almost wins but falls short by a small margin, which motivates gambling by making it feel like success is within reach. Existing research has extensively investigated the influence of contextual information on near-miss outcome processing; however, the impact of reward expectancy has received limited attention thus far. To address this gap, we utilized the wheel of fortune task and event-related potential technique (ERP) to quantify the electrophysiological responses associated with gambling outcomes at different levels of reward expectancy. Behaviorally, near-miss outcomes elicited a greater occurrence of counterfactual thoughts, feelings of regret, and heightened anticipation of rewards for subsequent trials compared to full-miss outcomes. ERP findings indicated that in contrast to full-miss outcomes, near-miss outcomes diminished feedback-related negativities (FRNs) and amplified P300s when reward expectancy was low, but amplified FRNs and diminished P300s when reward expectancy was high. These findings provide valuable insights into the neural mechanisms underlying the processing of outcome proximity and reward expectancy.