Understanding the dopaminergic system is a priority in neurobiology and neuropharmacology. Dopamine receptors are involved in the modulation of fundamental physiological functions, and dysregulation of dopaminergic transmission is associated with major neurological disorders. However, the available tools to dissect the endogenous dopaminergic circuits have limited specificity, reversibility, resolution, or require genetic manipulation. Here, we introduce azodopa, a novel photoswitchable ligand that enables reversible spatiotemporal control of dopaminergic transmission. We demonstrate that azodopa activates D₁-like receptors in vitro in a light-dependent manner. Moreover, it enables reversibly photocontrolling zebrafish motility on a timescale of seconds and allows separating the retinal component of dopaminergic neurotransmission. Azodopa increases the overall neural activity in the cortex of anesthetized mice and displays illumination-dependent activity in individual cells. Azodopa is the first photoswitchable dopamine agonist with demonstrated efficacy in wild-type animals and opens the way to remotely controlling dopaminergic neurotransmission for fundamental and therapeutic purposes.

Dural-based lymphomas are rare extranodal non-Hodgkin lymphomas that span from indolent primary dural entities, most commonly the extranodal marginal zone (mucosa-associated lymphoid tissue) lymphoma, to aggressive variants that are primary or represent secondary involvement from systemic lymphoma. They overlap radiologically with benign meningiomas, dural metastases, and immune-mediated pachymeningitis, creating a risk of anchoring bias, delayed diagnosis, and unnecessarily extensive resections when limited tissue sampling would be sufficient for diagnosis. We conducted a structured narrative review to synthesize the epidemiology, clinico-pathological classification, imaging phenotypes, and management principles of dural lymphomatous disease. This study will especially focus on primary dural lymphoma (PDL) with additional discussion of secondary dural involvement. Emphasis is placed on the clinical value of a multiparametric diagnostic approach that integrates computed tomography contrast-enhanced magnetic resonance imaging with functional techniques, and fluorodeoxyglucose positron emission tomography/computed tomography for systemic staging and for distinguishing truly localized primary dural lymphoma from secondary involvement. Potential diagnostic pitfalls related to somatostatin receptor–based tracer uptake will also be discussed. We introduced a pragmatic operational framework based on four clinico-biological clusters, translated into a step-by-step decision algorithm that prioritizes timely biopsy and comprehensive hematologic staging to guide surgical strategy. Given the absence of dedicated, multidisciplinary guidance for dural-based lymphomas, this algorithm is intended as a reproducible foundation for consensus recommendations and future multicenter validation.

BACKGROUND AND OBJECTIVES: Circumferential defects of the dural sleeve of exiting lumbar nerve roots may occur after incidental durotomy, trauma, or deliberate opening of the root cuff during resection of nerve sheath tumors. Standard onlay duraplasty can control cerebrospinal fluid (CSF) leakage but does not restore the tubular dural-epineural conduit. We describe a collagen-matrix cuff technique for root sleeve reconstruction and report our initial institutional experience. METHODS: This single-center, retrospective case series includes 9 consecutive reconstructions performed between January 2022 and October 2025 for intraoperatively recognized circumferential defects of exiting lumbar nerve root sleeves not amenable to safe primary suturing. The cohort comprised 6 iatrogenic root sleeve defects occurring during elective lumbar procedures (including instrumented and noninstrumented decompressive and/or stabilizing surgeries), 2 post-traumatic cases, and 1 elective tumor case presented as the illustrative case (L3 nerve root ganglioneuroma resection). Clinical records, intraoperative notes, and imaging were reviewed retrospectively. Minimum clinical and MRI follow-up was 6 months for all patients. Adjunctive lumbar drainage was used in one iatrogenic case. RESULTS: In all cases, a bovine pericardium–derived collagen matrix was prehydrated, tailored, positioned under the root, sutured proximally to the dural margin at the root axilla, and wrapped to form a tubular cuff bridging the dural sac to the epineural segment, with distal reinforcement using fat and fibrin sealant. No patient required reoperation for CSF leak or pseudomeningocele. There were no cases of symptomatic nerve root herniation or new permanent neurological deficit. Radicular symptoms were stable or improved at the last follow-up. CONCLUSION: Collagen-matrix cuff reconstruction is a simple, anatomically oriented option for circumferential lumbar root sleeve defects when primary closure is not feasible. In this initial single-center experience, the technique provided stable reconstruction without CSF-related complications and may represent a useful adjunct in selected complex root sleeve injuries.

Background/Objectives: Differentiating tumour recurrence from treatment-related changes (TRC) after multimodal treatment of high-grade gliomas (HGGs) remains challenging because of the overlap in imaging findings on conventional magnetic resonance. This study compared the diagnostic performance of the main static semiquantitative O-(2-[¹⁸F]fluoroethyl)-L-tyrosine positron emission tomography ([¹⁸F]FET-PET) parameters and assessed the diagnostic contribution of qualitative tracer uptake. Methods: This retrospective single-centre study included 77 scans from 61 adult patients with previously resected and chemoradiotherapy-treated HGGs undergoing [¹⁸F]FET-PET for suspected recurrence. Standardised uptake values (SUVs), tumour-to-background ratios (TBRs), and metabolic tumour volume (MTV) were analysed. Recurrence was determined using a composite histopathological and clinical–radiological reference standard. Diagnostic performance was assessed using receiver operating characteristic analysis, Youden-derived cut-offs and DeLong comparisons. Internal validation was performed by using patient-grouped five-fold cross-validation, in which cut-offs were re-derived within each training partition and applied to the held-out partition. Results: Forty-nine scans were classified as recurrence and 28 as TRC. All semiquantitative parameters except MTV were significantly higher in recurrent disease after false-discovery-rate correction. TBR mean ratio showed the highest accuracy (AUC, 0.80; cut-off, 1.85; sensitivity, 77.6%; specificity, 75.0%), followed by SUV max (AUC, 0.793). Neither prespecified comparison among TBR parameters was significant. The presence of pathological uptake achieved 100% sensitivity, 42.9% specificity, 100% NPV, and 79.2% accuracy. MTV was non-discriminative (AUC, 0.499). SUV max differed significantly between scanners (p = 0.008). Conclusions: Static semiquantitative [¹⁸F]FET-PET parameters, except MTV, showed comparable moderate-to-good performance for distinguishing recurrence from TRC. TBRmean may represent a pragmatic primary marker due to its background normalisation reduction of scanner-related variability. Guideline-recommended thresholds should be regarded as reference values requiring local validation and, when appropriate, centre- and protocol-specific calibration.

Dural-based lymphomas are rare extranodal non-Hodgkin lymphomas that span from indolent primary dural entities, most commonly extranodal marginal zone (mucosa-associated lymphoid tissue) lymphoma, to aggressive variants that are primary or represent secondary involvement from systemic lymphoma. They overlap radiologically with benign meningiomas, dural metastases, and immune-mediated pachymeningitis, creating a risk of anchoring bias, delayed diagnosis, and unnecessarily extensive resections when limited tissue sampling would be sufficient for diagnosis. We conducted a structured narrative review to synthesize the epidemiology, clinico-pathological classification, imaging phenotypes, and management principles of dural lymphomatous disease. This study will especially focus on primary dural lymphoma (PDL) with additional discussion of secondary dural involvement. Emphasis is placed on the clinical value of a multiparametric diagnostic approach that integrates computed tomography contrast-enhanced magnetic resonance imaging with functional techniques, and fluorodeoxyglucose positron emission tomography/computed tomography for systemic staging and for distinguishing truly localized primary dural lymphoma from secondary involvement. Potential diagnostic pitfalls related to somatostatin receptor–based tracer uptake will also be discussed. We introduced a pragmatic operational framework based on four clinico-biological clusters, translated into a step-by-step decision algorithm that prioritizes timely biopsy and comprehensive hematologic staging to guide surgical strategy. Given the absence of dedicated, multidisciplinary guidance for dural-based lymphomas, this algorithm is intended as a reproducible foundation for consensus recommendations and future multicenter validation.