149 words) 18

Protein engineering and experiment design: JSM, LLL Hippocampal slice imaging: TPJ, DAR Visual cortex volume imaging: KP, ON Mouse epilepsy model: YS, VM, ML, DMK Mitochondria experiments: ELK, NJL Zebrafish: TK, MBA Abstract (150 words)Current techniques for monitoring GABA, the primary inhibitory neurotransmitter in vertebrates, cannot follow ephemeral transients in intact neural circuits. We applied the design principles used to create iGluSnFR, a fluorescent reporter of synaptic glutamate, to develop a GABA sensor using a protein derived from a previously unsequenced Pseudomonas fluorescens strain. Structure-guided mutagenesis and library screening led to a usable iGABASnFR (∆F/Fmax ~ 2.5, Kd ~ 9 µM, good specificity, adequate kinetics). iGABASnFR is genetically encoded, detects single action potential-evoked GABA release events in culture, and produces readily detectable fluorescence increases in vivo in mice and zebrafish. iGABASnFR enabled tracking of: (1) mitochondrial GABA content and its modulation by an anticonvulsant; (2) swimming-evoked GABAergic transmission in zebrafish cerebellum; (3) GABA release events during inter-ictal spikes and seizures in awake mice; and (4) GABAergic tone decreases during isoflurane anesthesia. iGABASnFR will permit high spatiotemporal resolution of GABA signaling in intact preparations.

Background: The presence of high-density starry dots around the intracerebral hemorrhage (ICH), which we termed as a satellite sign, is occasionally observed in CT. The relationship between ICH with a satellite sign and its functional outcome has not been identified. This study aimed to determine whether the presence of a satellite sign could be an independent prognostic factor for patients with ICH. Methods: Patients with acute spontaneous ICH were retrospectively identified and their initial CT scans were reviewed. A satellite sign was defined as scattered high-density lesions completely separate from the main hemorrhage in at least the single axial slice. Functional outcome was evaluated using the modified Rankin Scale (mRS) at discharge. Poor functional outcome was defined as mRS scores of 3-6. Univariate and multivariate logistic regression analyses were applied to assess the presence of a satellite sign and its association with poor functional outcome. Results: A total of 241 patients with ICH were enrolled in the study. Of these, 98 (40.7%) had a satellite sign. Patients with a satellite sign had a significantly higher rate of poor functional outcome (95.9%) than those without a satellite sign (55.9%, p < 0.0001). Multivariate logistic regression analysis revealed that higher age (OR 1.06; 95% CI 1.03-1.10; p = 0.00016), large hemorrhage size (OR 1.06; 95% CI 1.03-1.11; p = 0.00015), and ICH with a satellite sign (OR 13.5; 95% CI 4.42-53.4; p < 0.0001) were significantly related to poor outcome. A satellite sign was significantly related with higher systolic blood pressure (p = 0.0014), higher diastolic blood pressure (p = 0.0117), shorter activated partial thromboplastin time (p = 0.0427), higher rate of intraventricular bleeding (p < 0.0001), and larger main hemorrhage (p < 0.0001). Conclusions: The presence of a satellite sign in the initial CT scan is associated with a significantly worse functional outcome in ICH patients.

BackgroundCryptococcal meningoencephalitis (CM) causes cerebral infarction, typically, lacunar infarction in the basal ganglia. However, massive cerebral infarction leading to death is rare and its pathophysiology is unclear. We report a case of CM causing massive cerebellar infarction, which led to cerebral herniation and death.Case presentationA 56-year-old man who suffered from dizziness and gait disturbance for one month was admitted to our hospital and subsequently diagnosed with a cerebellar infarction. He had a past medical history of hepatitis type B virus infection and hepatic failure. Although the findings on magnetic resonance imaging (MRI) imitated an arterial infarction of the posterior inferior cerebellar artery, an accompanying irregular peripheral edema was observed. The ischemic lesion progressed, subsequently exerting a mass effect and leading to impaired consciousness. External and internal decompression surgeries were performed. Cryptococcus neoformans was confirmed in the surgical specimen, and the patient was diagnosed with CM. In addition, venule congestion in the parenchyma was observed with extensive fibrosis and compressed veins in the subarachnoid space. The patient died 26 days after admission. Autopsy revealed that pathological changes were localized in the cerebellum.Conclusion C. neoformans can induce extensive fibrosis of the subarachnoid space, which may compress small veins mechanically inducing venule congestion and massive cerebral infarction. In such cases, the clinical course can be severe and even rapidly fatal. An atypical pattern of infarction on MRI should alert clinicians to the possibility of C. neoformans infection.