Taro Murakami

Neuroanatomic Pathways Associated with Poststroke Affective and Apathetic Depression

OBJECTIVES Our goal was to localize lesions in poststroke depression patients using magnetic resonance imaging, based on the statistical parametric maps image analysis technique that can be used to combine image data from multiple participants and correlate these images with other data sets. METHODS Magnetic resonance imaging acquisitions were obtained from 149 poststroke patients, who were assessed for affective and apathetic symptoms using the Hospital Anxiety and Depression Scale and the Apathy Scale, respectively. We created a statistical parametric map that displayed an association between lesion location and affective and apathetic symptoms. RESULTS Among the patients with higher depressive scores, the lesion overlap centered on the brainstem, left basal ganglia, and left frontal cortex. Among the patients with higher apathy scores, the lesion overlap centered on the brainstem and bilateral striatum. The overlap lesion for both affective and apathetic depression centered mainly on the brainstem; however, the two types of depression often did not overlap. CONCLUSIONS Two core symptoms that can occur after stroke, affective and apathetic symptoms, appear to be associated with different monoaminergic neuroanatomic pathways (serotonergic and dopaminergic).

Neuroanatomic pathway associated with attentional deficits after stroke

We used magnetic resonance imaging (MRI) and the statistical parametric mapping (SPM) image analysis technique to localize lesions in post-stroke patients with attention deficits. SPM can be used to combine image data from multiple participants and correlate these images with other data sets. Magnetic resonance imaging acquisitions were obtained from 115 post-stroke patients, who were systemically assessed for attention deficits using a standardized test (the Clinical Assessment for Attention; CAT) that probes various domains of attention. We created an SPM that displayed an association between lesion location and attention deficit severity. The overlay plots were localized to the right hemisphere during a visual cancellation test, and were localized to the left hemisphere during other attention tests. Cortical lesion varied across specific test domain, whereas lesions from the thalamus to the basal ganglia on the dominant side were associated with performance across all attention tests/domains. Our findings are suggestive of a large-scale multimodal attentional network associated with the thalamus/basal ganglia.

Neuroanatomic pathways associated with monoaminergic dysregulation after stroke

We examined the complex relationship between lesion location, symptoms of depression (affective and apathetic), and monoamine dysfunction after stroke.

Retinoblastoma protein prevents staurosporine-induced cell death in a retinoblastoma-defective human glioma cell line.

Objective: To investigate the mechanism of staurosporine-induced glioma cell death and cell cycle arrest using adenovirus-mediated gene transfection, as well as the function of retinoblastoma (Rb) and genetic instability induced by staurosporine. Methods: Cell cycle regulation, cell death and nuclear abnormalities induced by staurosporine were examined using an adenovirus vector expressing Rb, p16 or p21 genes in human glioma cell lines. Results: The Rb-defective SF-539 cell line was resistant to staurosporine compared with cell lines expressing intact Rb. SF-539 glioma cells exposed to staurosporine became multinucleated and then died. Multinucleation was prevented in SF-539 cells transfected with the Rb gene, thus decreasing the death rate of these cells. Conclusions: These results imply that enforced Rb expression protects cells from genomic instability induced by staurosporine regardless of its upstream molecular effects.