p75NTR and DR6 Regulate Distinct Phases of Axon Degeneration Demarcated by Spheroid Rupture.

The regressive events associated with trophic deprivation are critical for sculpting a functional nervous system. After nerve growth factor withdrawal, sympathetic axons derived from male and female neonatal mice maintain their structural integrity for ∼18 h (latent phase) followed by a rapid and near unison disassembly of axons over the next 3 h (catastrophic phase). Here we examine the molecular basis by which axons transition from latent to catastrophic phases of degeneration following trophic withdrawal. Before catastrophic degeneration, we observed an increase in intra-axonal calcium. This calcium flux is accompanied by p75 neurotrophic factor receptor-Rho-actin-dependent expansion of calcium-rich axonal spheroids that eventually rupture, releasing their contents to the extracellular space. Conditioned media derived from degenerating axons are capable of hastening transition into the catastrophic phase of degeneration. We also found that death receptor 6, but not p75 neurotrophic factor receptor, is required for transition into the catastrophic phase in response to conditioned media but not for the intra-axonal calcium flux, spheroid formation, or rupture that occur toward the end of latency. Our results support the existence of an interaxonal degenerative signal that promotes catastrophic degeneration among trophically deprived axons.SIGNIFICANCE STATEMENT Developmental pruning shares several morphological similarities to both disease- and injury-induced degeneration, including spheroid formation. The function and underlying mechanisms governing axonal spheroid formation, however, remain unclear. In this study, we report that axons coordinate each other's degeneration during development via axonal spheroid rupture. Before irreversible breakdown of the axon in response to trophic withdrawal, p75 neurotrophic factor receptor-RhoA signaling governs the formation and growth of spheroids. These spheroids then rupture, allowing exchange of contents ≤10 kDa between the intracellular and extracellular space to drive death receptor 6 and calpain-dependent catastrophic degeneration. This finding informs not only our understanding of regressive events during development but may also provide a rationale for designing new treatments toward myriad neurodegenerative disorders.

Evidence for the Role of the Cecal Microbiome in Maintenance of Immune Regulation and Homeostasis.

OBJECTIVE (S): Our objective was to investigate alterations in the cecal microbial composition during the development of type 1 diabetes (T1D) with or without IgM therapy, and correlate these alterations with the corresponding immune profile. METHODS: (1) Female nonobese diabetic (NOD) mice treated with IgM or saline (n = 20/group) were divided into 5-week-old nondiabetic; 9 to 12-week-old prehyperglycemic stage-1; ≥13-week-old prehyperglycemic stage-2; and diabetic groups. 16S rRNA libraries were prepared from bacterial DNA and deep-sequenced. (2) New-onset diabetic mice were treated with IgM (200 µg on Days 1, 3, and 5) and their blood glucose monitored for 2 months. RESULTS: Significant dysbiosis was observed in the cecal microbiome with the progression of T1D development. The alteration in microbiome composition was characterized by an increase in the bacteroidetes:firmicutes ratio. In contrast, IgM conserved normal bacteroidetes:firmicutes ratio and this effect was long-lasting. Furthermore, oral gavage using cecal content from IgM-treated mice significantly diminished the incidence of diabetes compared with controls, indicating that IgM specifically affected mucosa-associated microbes, and that the affect was causal and not an epiphenomenon. Also, regulatory immune cell populations (myeloid-derived suppressor cells and regulatory T cells) were expanded and insulin autoantibody production diminished in the IgM-treated mice. In addition, IgM therapy reversed hyperglycemia in 70% of new-onset diabetic mice (n = 10) and the mice remained normoglycemic for the entire post-treatment observation period. CONCLUSIONS: The cecal microbiome appears to be important in maintaining immune homeostasis and normal immune responses.

The Impact of Big Data on Chronic Disease Management.

Population health management and specifically chronic disease management depend on the ability of providers to prevent development of high-cost and high-risk conditions such as diabetes, heart failure, and chronic respiratory diseases and to control them. The advent of big data analytics has potential to empower health care providers to make timely and truly evidence-based informed decisions to provide more effective and personalized treatment while reducing the costs of this care to patients. The goal of this study was to identify real-world health care applications of big data analytics to determine its effectiveness in both patient outcomes and the relief of financial burdens. The methodology for this study was a literature review utilizing 49 articles. Evidence of big data analytics being largely beneficial in the areas of risk prediction, diagnostic accuracy and patient outcome improvement, hospital readmission reduction, treatment guidance, and cost reduction was noted. Initial applications of big data analytics have proved useful in various phases of chronic disease management and could help reduce the chronic disease burden.

Potentially reversible acute cerebellar toxicity associated with Minnelide.

PURPOSE: Minnelide is an experimental antineoplastic agent that is currently the subject of a phase 1 clinical trial for the treatment of pancreatic and gastrointestinal malignancies. In this study, we documented two cases of reversible acute cerebellar toxicity (REACT) associated with Minnelide and compared its radiological manifestations with other cerebellotoxic agents. METHODS: Both patients had histories of progressive metastatic cancer and participated in a phase 1 clinical trial with Minnelide. They had an MRI examination including T2WI, FLAIR and SWI, axial and coronal DWI, and ADC map on admission and follow up. RESULTS: In each patient, the initial MRI demonstrated increased signal on FLAIR and restricted diffusion in the cerebellar cortex without involvement of deep cerebellar nuclei or supratentorial areas. The presenting symptoms and the majority of imaging findings resolved on follow up MRI. CONCLUSION: To our knowledge, Minnelide has shown an uncommon radiologic pattern of isolated cerebellar cortical involvement compared to other causes of cerebellar toxicity. Since this is a new medication, physicians' familiarity with the presenting symptoms and its temporal association with the imaging findings is important.

NtERF32: a non-NIC2 locus AP2/ERF transcription factor required in jasmonate-inducible nicotine biosynthesis in tobacco.

Nicotine biosynthesis in tobacco (Nicotiana tabacum L.) is highly regulated by jasmonic acid (JA). Two nuclear loci, A and B (renamed NIC1 and NIC2) have been identified that mediate JA-inducible nicotine formation and total alkaloid accumulation. NIC2 was recently shown to be a cluster of seven genes encoding Apetala2/Ethylene-Response Factor (AP2/ERF)-domain transcription factors (TFs) in Group IX of the tobacco AP2/ERF family. Here we report the characterization of several NtERF TF genes that are not within the NIC2 locus, but required for methyl JA (MeJA)-induced nicotine biosynthesis. Expression of NtERF1, NtERF32, and NtERF121 is rapidly induced (<30 min) by MeJA treatment. All three of these TFs specifically bind the GCC box-like element of the GAG motif required for MeJA-induced transcription of NtPMT1a, a gene encoding putrescine N-methyltransferase, the first committed step in the synthesis of the nicotine pyrrolidine ring. Ectopic overexpression of NtERF32 increases expression of NtPMT1a in vivo and elevates total alkaloid contents, whereas RNAi-mediated knockdown of NtERF32 reduces the mRNA levels of multiple genes in the nicotine biosynthetic pathway including NtPMT1a and quinolinate phosphoribosyltransferase (NtQPT2), and lowers nicotine and total alkaloid levels. We conclude that NtERF32 and related ERF genes are important non-NIC2 locus associated transcriptional regulators of nicotine and total alkaloid formation.

Comparative Efficacy and Safety of Self-Expandable vs. Balloon-Expandable Stent Grafts in Visceral Artery Aneurysm Management.

PURPOSE: This study assesses the efficacy and safety of self-expandable (SE) versus balloon-expandable (BE) stent grafts for managing visceral artery aneurysms (VAAs), focusing on procedural success and complication rates. MATERIALS AND METHODS: We conducted a retrospective analysis of VAA patients treated at our institution from April 2006 to September 2021. The study reviewed patient demographics, aneurysm characteristics, treatment details, and outcomes, including endoleaks. RESULTS: Among the 23 patients analyzed, splenic artery aneurysms represented 44% of cases. Fifteen patients were treated with balloon-expandable stent grafts (BE SGs), and eight patients were treated with self-expandable stent grafts (SE SGs). For saccular aneurysms, the average neck size was 10.10 ± 8.70 mm in the BE group versus 18.50 ± 3.40 mm in the SE group (p = 0.23), with an average sac size of 20.10 ± 18.9 mm in the BE group versus 15.60 ± 12.7 mm in the SE group (p = 0.16). The average sac-to-neck ratio was 1.69 ± 2.23 in the BE group versus 1.38 ± 0.33 in the SE group (p = 0.63). The BE group exhibited a significantly higher endoleak rate (60%) compared to the SE group (12.5%; p = 0.03). CONCLUSIONS: While further investigation is needed to fully assess the outcomes of stent graft treatment for VAAs, initial data show a significantly higher endoleak rate with BE SGs compared to SE SGs. The SE SGs may offer better outcomes due to their superior ability to conform to tortuous and mobile visceral arteries.

Irreversible Electroporation as a Valid Treatment Option for Hepatic Epithelioid Hemangioendothelioma: An International Multicenter Experience.

PURPOSE: Hepatic epithelioid hemangioendothelioma (HEHE) is a rare tumor with currently no established standard of care. This international multicenter retrospective study assesses the use of percutaneous irreversible electroporation (IRE) as an ablative tool to treat HEHE and provides a clinical overview of the current management and role of IRE in HEHE treatment. MATERIAL AND METHODS: Between 2017 and 2023, 14 patients with 47 HEHE tumors were treated with percutaneous IRE using CT-scan guidance in 23 procedures. Baseline patient and tumor characteristics were evaluated. Primary outcome measures included safety and effectiveness, analyzed using Common Terminology Criteria for Adverse Events (CTCAE) and treatment response by mRECIST criteria. Secondary outcome measures included technical success, post-treatment tumor sizes and length of hospital stay. Technical success was defined as complete ablation with an adequate ablative margin (intentional tumor free ablation margin > 5 mm). RESULTS: IRE treatment resulted in technical success in all tumors. Following a median follow-up of 15 months, 30 tumors demonstrated a complete response according to mRECIST criteria. The average tumor size pre-treatment was 25.8 mm, accompanied by an average reduction in tumor size by 7.5 mm. In 38 out of 47 tumors, there was no evidence of local recurrence. In nine tumors, residual tumor was present. There were no cases of progressive disease. Median length of hospital stay was one day. Only one grade 3 CTCAE event occurred, a pneumothorax requiring chest tube placement. CONCLUSION: The current study provides evidence that IRE is a safe and efficacious minimally invasive treatment option for HEHE.

The practical limits of high-quality magnetic resonance imaging for the diagnosis and classification of trigeminal neuralgia.

BACKGROUND: Neurovascular compression (NVC) has been the primary hypothesis for the underlying mechanism of classical trigeminal neuralgia (TN). However, a substantial body of literature has emerged highlighting notable exceptions to this hypothesis. The purpose of this study is to assess the reliability and diagnostic accuracy of high resolution, high contrast MRI-determined neurovascular contact for TN. METHODS: We performed a retrospective, randomized, and blinded parallel characterization of neurovascular interaction and diagnosis in a population of TN patients and controls using four expert reviewers. Performance statistics were calculated, as well as assessments for generalizability using shuffled bootstraps. RESULTS: Fair to moderate agreement (ICC: 0.32-0.68) about diagnosis between reviewers was observed using MRIs from 47 TN patients and 47 controls. On average reviewers performed no better than chance when diagnosing participants, with an accuracy of 0.57 (95% CI 0.40, 0.59) per patient. CONCLUSION: While MRI is useful in determining structural causes in secondary TN, expert reviewers do no better to only slightly better than chance with distinguishing TN with MRI, despite moderate agreement. Further, the causal role of NVC for TN is not clear, limiting the applicability of MRI to diagnose or prognosticate treatment of TN.

Food-induced dopamine signaling in AgRP neurons promotes feeding.

Obesity comorbidities such as diabetes and cardiovascular disease are pressing public health concerns. Overconsumption of calories leads to weight gain; however, neural mechanisms underlying excessive food consumption are poorly understood. Here, we demonstrate that dopamine receptor D1 (Drd1) expressed in the agouti-related peptide/neuropeptide Y (AgRP/NPY) neurons of the arcuate hypothalamus is required for appropriate responses to a high-fat diet (HFD). Stimulation of Drd1 and AgRP/NPY co-expressing arcuate neurons is sufficient to induce voracious feeding. Delivery of a HFD after food deprivation acutely induces dopamine (DA) release in the ARC, whereas animals that lack Drd1 expression in ARCAgRP/NPY neurons (Drd1AgRP-KO) exhibit attenuated foraging and refeeding of HFD. These results define a role for the DA input to the ARC that encodes acute responses to food and position Drd1 signaling in the ARCAgRP/NPY neurons as an integrator of the hedonic and homeostatic neuronal feeding circuits.

A new reference line for coronal head CT to align with MRI: development of a standardised approach.

BACKGROUND AND PURPOSE: There are great variations in how different technologists create the different imaging planes that can make a precise comparison of computed tomography and magnetic resonance imaging difficult. We aimed to identify a reference line for the coronal images on a computed tomography topography parallel to the posterior borderline of the brainstem (PB), matching standard coronal magnetic resonance imaging planes. METHODS: We retrospectively reviewed computed tomography topography images of 80 consecutive patients to determine a computed tomography plane to match the PB on magnetic resonance imaging. These included the tuberculum sella (TS)-anterior arch of the C1 vertebra (C1), TS-tip of dens axis (D), dorsum sellae (DS)-C1 and DS-D. We compared these methods of prescribing the coronal computed tomography plane to coronal magnetic resonance imaging planes by measuring the angles between TS-C1 and PB, TS-M and PB, DS-C1 and PB, DS-D and PB on midsagittal brain magnetic resonance images. Bland-Altman plots were created to assess intra-observer reliability. RESULTS: The angles between the PB line and each topogram-determined line are as follows: TS-C1, 10.40° ± 4.86°; TS-D, 22.46° ± 5.23°; DS-C1, 3.01° ± 3.16°; and DS-D, 11.53° ± 4.10°. The mean angles between the DS-C1 and the PB lines were significantly smaller than the mean angle between any other line (DS-D, TS-C1, or TS-D, all P < 0.001). Intra-observer agreement regarding the angular position of the reformatted coronal images on the lateral scout image was excellent (intraclass correlation coefficient >0.900, P < 0.05). CONCLUSIONS: The DS-C1 is almost parallel to the PB and easily identifiable on the lateral scout topography of brain computed tomography. Utilising the DS-C1 line as the baseline for brain computed tomography could allow better corroboration with coronal magnetic resonance imaging angulation.

Recanalization and Reconstruction of a Chronically Occluded Inferior Vena Cava Through an Existing Transjugular Intrahepatic Portosystemic Shunt in the Setting of Budd-Chiari Syndrome.

Budd-Chiari syndrome (BCS) results from the occlusion or flow reduction in the hepatic veins or inferior vena cava and can be treated with transjugular intrahepatic portosystemic shunt when hepatic vein recanalization fails.1-3 Hypercoagulable patients with primary BCS are predisposed to development of new areas of thrombosis within the TIPS shunt or IVC. This case details a patient with BCS, pre-existing TIPS extending to the right atrium, and chronic retrohepatic IVC thrombosis who underwent sharp recanalization of the IVC with stenting into the TIPS stent bridging the patient until his subsequent hepatic transplantation.

Splenic Artery Embolization for Treatment of Iatrogenic Kasabach-Merritt Phenomenon Following Failed Endovascular Splenic Artery Aneurysm Repair.

Stent grafts are utilized to treat and exclude visceral arterial aneurysms while preserving flow through the vessel. Stent-associated thrombocytopenia is a rare complication not typically seen with modern stents. The following case describes the clinical presentation of stent kinking and consumptive coagulopathy. Stent-associated microangiopathic hemolytic anemia was inferred from protracted workup and exclusion of alternative diagnoses. Despite the risk of arterial puncture in the setting of profound thrombocytopenia, the patient was successfully treated with stent embolization with near immediate rebound in platelet count. This case report documents the presentation of rare stent-associated thrombocytopenia leading to challenging diagnostic evaluation and necessitating high-risk intervention.

The Potential for Undue Patient Exposure during the Use of Telementoring Technology.

Background Surgical telementoring holds great promise for safe and effective patient care and medical education, but recording and streaming audio and video introduces the potential for exposure of patient information. Physicians maintain an ethical responsibility to protect the privacy of patients, and privacy violations may carry significant legal liability. Despite the legal treatment of violations as discrete, methods for quantifying and characterizing the exposure of patient information during procedural recordings are lacking. This study is the first to quantify the potential risk for violation of privacy when using a wearable, telementoring technology capable of video and audio recording during surgical procedures in various locations including the operating room, interventional radiology suite, and the intensive care unit. Methods A head-mounted recording device, Google Glass™, was used to record routine neurosurgical and critical care procedures in a convenience sample of patients. Periods of maximal risk, including the beginning of procedures, were targeted. Recordings were manually coded for discrete instances of exposure of directly identifying information and indirectly identifying information. Results Twenty-two procedures were recorded for a total of 12 hours, during which 807 directly identifiable exposures were found. The overall average rate of exposure was 1.13 exposures per minute. Most exposures were full-face images (90%), names (7%), or phone numbers (3%). Indirectly identifying exposures were found to be tattoos, genitals, and caretaker names. The rate of exposures was found to be lower in the operating room (OR) when compared to the intensive care unit (ICU) or interventional radiology (IR) suite (p = 0.0376). Conclusions High rates of potential privacy violations were discovered and found to be related the location of the procedure. Sterile draping of the face prior to recording, when appropriate, would mitigate most exposure risk, though patient names and unique tattoos may be an underappreciated source of potential exposure. This study establishes the most conservative baseline to compare techniques for preventing exposure of patient information on telementoring or video/audio recording/streaming platforms.

Regulation of degenerative spheroids after injury.

Neuronal injury leads to rapid, programmed disintegration of axons distal to the site of lesion. Much like other forms of axon degeneration (e.g. developmental pruning, toxic insult from neurodegenerative disorder), Wallerian degeneration associated with injury is preceded by spheroid formation along axons. The mechanisms by which injury leads to formation of spheroids and whether these spheroids have a functional role in degeneration remain elusive. Here, using neonatal mouse primary sympathetic neurons, we investigate the roles of players previously implicated in the progression of Wallerian degeneration in injury-induced spheroid formation. We find that intra-axonal calcium flux is accompanied by actin-Rho dependent growth of calcium rich axonal spheroids that eventually rupture, releasing material to the extracellular space prior to catastrophic axon degeneration. Importantly, after injury, Sarm1-/- and DR6-/-, but not Wlds (excess NAD+) neurons, are capable of forming spheroids that eventually rupture, releasing their contents to the extracellular space to promote degeneration. Supplementation of exogenous NAD+ or expressing WLDs suppresses Rho-dependent spheroid formation and degeneration in response to injury. Moreover, injured or trophically deprived Sarm1-/- and DR6-/-, but not Wlds neurons, are resistant to degeneration induced by conditioned media collected from wild-type axons after spheroid rupture. Taken together, these findings place Rho-actin and NAD+ upstream of spheroid formation and may suggest that other mediators of degeneration, such as DR6 and SARM1, mediate post-spheroid rupture events that lead to catastrophic axon disassembly.

Dopamine Signaling in the Suprachiasmatic Nucleus Enables Weight Gain Associated with Hedonic Feeding.

The widespread availability of energy-dense, rewarding foods is correlated with the increased incidence of obesity across the globe. Overeating during mealtimes and unscheduled snacking disrupts timed metabolic processes, which further contribute to weight gain. The neuronal mechanism by which the consumption of energy-dense food restructures the timing of feeding is poorly understood. Here, we demonstrate that dopaminergic signaling within the suprachiasmatic nucleus (SCN), the central circadian pacemaker, disrupts the timing of feeding, resulting in overconsumption of food. D1 dopamine receptor (Drd1)-null mice are resistant to diet-induced obesity, metabolic disease, and circadian disruption associated with energy-dense diets. Conversely, genetic rescue of Drd1 expression within the SCN restores diet-induced overconsumption, weight gain, and obesogenic symptoms. Access to rewarding food increases SCN dopamine turnover, and elevated Drd1-signaling decreases SCN neuronal activity, which we posit disinhibits downstream orexigenic responses. These findings define a connection between the reward and circadian pathways in the regulation of pathological calorie consumption.

Beta-tubulin isotype classes II and V expression patterns in nonsmall cell lung carcinomas.

Previous studies suggest that beta-tubulin isotype protein levels could be useful as indicators of nonsmall cell lung cancer (NSCLC) aggressiveness. However, measurement of protein amounts in tissue samples by staining techniques is semiquantitative at best. Since technologies for measuring mRNA levels have become more efficient and quantitative, we wanted to determine whether beta-tubulin message levels may be useful as biomarkers. Quantitative real-time RT-PCR was used to measure the seven classes of beta-tubulin isotypes, stathmin and MAP4 mRNA levels in 64 NSCLC and 12 normal lung tissue samples. We found significantly higher fractions of beta-tubulin classes II and V mRNA compared to the other isotypes in all lung tumor samples (P < 0.05). In addition, the ratio of beta-tubulin classes II/V mRNA was significantly higher in NSCLCs compared to normal lung tissues (P < 0.001). The data suggest that the ratio of beta-tubulin classes II and V mRNA could be useful as a biomarker for NSCLC tumor differentiation and/or NSCLC aggressiveness. Furthermore, the ratio of MAP4 to stathmin mRNA was found to be higher in diseased lung tissues compared to normal lung tissues, suggesting this ratio might also be used as a clinically relevant biomarker for NSCLCs.

Utility of Likert scale (Deauville criteria) in assessment of Chemoradiotherapy response of primary oropharyngeal squamous cell Cancer site.

INTRODUCTION: The aim of this study is to determine whether Likert scale (Deauville criteria) can be used to classify oropharyngeal squamous cell cancer (OPSCC) patients as 'responders' and 'nonresponders' by utilizing FDG-PET/CT for primary tumor site. The second aim is to compare the performance of methods used in interpretation of posttreatment PET/CT scans (Likert scale, SUVmax, ratios of SUVmax primary lesion to mediastinum 'SUVmax P/M' and SUVmax primary lesion to liver 'SUVmax P/L') in predicting treatment response. METHODS: Seventy-seven PET/CT scans were assessed by Deauville criteria, five-point Likert scale. SUVmax of primary lesion, SUVmax primary to mediastinum and SUVmax primary to liver ratios on first follow-up PET/CT were measured and calculated. Pathology results, clinical and imaging follow-up were used as standart reference. RESULTS: Sensitivity, specificity, positive predictive and negative predictive value of Likert scale were found to be 80%, 89.5%, 53.3% and 96.8% respectively. When Likert scale and PET parameters were compared, no statistically significant difference was found. Receiver operating characteristic (ROC) was used to determine the optimal cut-off points for SUVmax (found as 4) and for ratios (SUVmax P/M = 1.67and SUVmax P/L = 1.7) with the highest specificity and NPV. CONCLUSION: Likert scale adequately categorize patients as 'responders' and 'non-responders'. Since its NPV is high and interpretation is relatively easy, it can be utilized to evaluate OPSCC response to treatment in first follow up FDG PET/CT.

Death Receptor 6 Promotes Wallerian Degeneration in Peripheral Axons.

Axon degeneration during development is required to sculpt a functional nervous system and is also a hallmark of pathological insult, such as injury [1, 2]. Despite similar morphological characteristics, very little overlap in molecular mechanisms has been reported between pathological and developmental degeneration [3-5]. In the peripheral nervous system (PNS), developmental axon pruning relies on receptor-mediated extrinsic degeneration mechanisms to determine which axons are maintained or degenerated [5-7]. Receptors have not been implicated in Wallerian axon degeneration; instead, axon autonomous, intrinsic mechanisms are thought to be the primary driver for this type of axon disintegration [8-10]. Here we survey the role of neuronally expressed, paralogous tumor necrosis factor receptor super family (TNFRSF) members in Wallerian degeneration. We find that an orphan receptor, death receptor 6 (DR6), is required to drive axon degeneration after axotomy in sympathetic and sensory neurons cultured in microfluidic devices. We sought to validate these in vitro findings in vivo using a transected sciatic nerve model. Consistent with the in vitro findings, DR6-/- animals displayed preserved axons up to 4 weeks after injury. In contrast to phenotypes observed in Wlds and Sarm1-/- mice, preserved axons in DR6-/- animals display profound myelin remodeling. This indicates that deterioration of axons and myelin after axotomy are mechanistically distinct processes. Finally, we find that JNK signaling after injury requires DR6, suggesting a link between this novel extrinsic pathway and the axon autonomous, intrinsic pathways that have become established for Wallerian degeneration.

Effect of protein orientation on electron transfer between photosynthetic reaction centers and carbon electrodes.

A new type of monolayer of photosynthetic reaction centers (RC) with the primary donor facing the carbon electrode has been constructed using a new bifunctional linker and genetically engineered protein. Comparison of protein in two different orientations with linkers binding to the opposite sides of the protein demonstrates the possibility of utilizing the constructed surfaces as photoelectronic devices. The results show improvement of the electron transfer efficiency when RC is bound with the primary donor (P) facing the electrode (P-side). In either protein orientation, electron transfer within the protein is unidirectional and when applying a voltage RC operates as a photorectifier. Electron transfer between the protein and carbon electrodes in the constructed devices is most likely occurring by tunneling.

Genetically targeted magnetic control of the nervous system.

Optogenetic and chemogenetic actuators are critical for deconstructing the neural correlates of behavior. However, these tools have several limitations, including invasive modes of stimulation or slow on/off kinetics. We have overcome these disadvantages by synthesizing a single-component, magnetically sensitive actuator, "Magneto," comprising the cation channel TRPV4 fused to the paramagnetic protein ferritin. We validated noninvasive magnetic control over neuronal activity by demonstrating remote stimulation of cells using in vitro calcium imaging assays, electrophysiological recordings in brain slices, in vivo electrophysiological recordings in the brains of freely moving mice, and behavioral outputs in zebrafish and mice. As proof of concept, we used Magneto to delineate a causal role of striatal dopamine receptor 1 neurons in mediating reward behavior in mice. Together our results present Magneto as an actuator capable of remotely controlling circuits associated with complex animal behaviors.