A Novel Quadrant Spatial Assay Reveals Environmental Preference in Mouse Spontaneous and Parental Behaviors.

Environmental factors have well-documented impacts on brain development and mental health. Therefore, it is crucial to employ a reliable assay system to assess the spatial preference of model animals. In this study, we introduced an unbiased quadrant chamber assay system and discovered that parental pup-gathering behavior takes place in a very efficient manner. Furthermore, we found that test mice exhibited preferences for specific environments in both spontaneous and parental pup-gathering behavior contexts. Notably, the spatial preferences of autism spectrum disorder model animals were initially suppressed but later equalized during the spontaneous behavior assay, accompanied by increased time spent in the preferred chamber. In conclusion, our novel quadrant chamber assay system provides an ideal platform for investigating the spatial preference of mice, offering potential applications in studying environmental impacts and exploring neurodevelopmental and psychiatric disorder models.

Neurolymphomatosis secondary to primary central nervous system lymphoma: illustrative case.

BACKGROUND: Neurolymphomatosis (NL) is a rare disease defined as an invasion of lymphoma into peripheral nerves, nerve roots, or nerve plexuses, including the cranial nerves. No clear treatment protocols have yet been defined for this pathology. OBSERVATIONS: A woman in her 40s had a primary central nervous system lymphoma diagnosed from an intracranial tumor biopsy and underwent chemotherapy and radiation therapy. After she complained of pain in the trunk and extremities, magnetic resonance imaging and [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) performed 25 months after initial diagnosis revealed multiple lesions in the nerve ganglia, plexuses, and peripheral nerves from the cervical to the sacral spinal cord. Cerebrospinal fluid cytology revealed atypical lymphocytes and lymphoma dissemination in the spinal cavity. Based on these findings, NL was diagnosed. An intrathecal antineoplastic regimen temporarily reduced abnormal uptake of FDG, but the lesion recurred. After additional high-dose methotrexate therapy, FDG accumulation in the previously identified lesions disappeared. However, peripheral neuropathic pain and paraplegia remained. The patient died 9 months after the initial diagnosis of NL. LESSONS: The authors reported a case of NL following primary central nervous system lymphoma. In this case, FDG-PET proved useful for diagnosis, and high-dose methotrexate therapy was temporarily effective. https://thejns.org/doi/suppl/10.3171/CASE24107.

Factors associated with decreasing diffusion-weighted imaging-positive area volume after mechanical thrombectomy in patients with large early ischemic changes.

OBJECTIVES: This study aimed to evaluate the factors associated with decreasing diffusion-weighted imaging (DWI) positive areas in patients with large early ischemic changes after mechanical thrombectomy (MT). MATERIALS AND METHODS: This retrospective single-center clinical study was conducted between January 2013 and December 2022. We included consecutive patients who underwent MT for acute large-vessel occlusion of the anterior circulation with low pretreatment DWI-Alberta Stroke Program Early Computed Tomography Scores (ASPECTS) (0-5), effective recanalization [thrombolysis in cerebral infarction (TICI) 2b or TICI3], and magnetic resonance imaging (MRI) acquired before and after MT. We measured the DWI-positive area volume before and after MT. The primary endpoint was the after/before-MT DWI-positive area-volume ratio. RESULTS: In total, 28 patients were included in this study. Eight patients (29%) had an after/before-MT DWI-positive area-volume ratio of <1. The median mean apparent diffusion coefficient (ADC) levels of the DWI-positive areas in the groups with a ratio of <1 or >1 were 717 × 106 mm2/s and 637 × 106 mm2/s, respectively (p = 0.011). Multivariate logistic regression analysis showed that ADC level (OR, 1.020 [95% confidence intervals (CIs), 1.001-1.040]; p = 0.040) was an independent predictor of a decreased DWI-positive area after MT. There was a negative correlation between the mean ADC level and the after/before-MT DWI-positive area-volume ratio (p < 0.001, |ρ| = 0.650), and the mean pretreatment ADC cutoff level was 649 × 106 mm2/s (area under the curve (AUC) = 0.806) for predicting a volume ratio of <1. CONCLUSIONS: The mean ADC level before-MT correlated with the after/before-MT DWI-positive area-volume ratio. A mean pretreatment ADC cutoff level of 649 × 106 mm2/s predicted a decreased DWI-positive area after MT.