Neuroscience research
-
Neuroscience research · Nov 2011
RA-GEF-1 (Rapgef2) is essential for proper development of the midline commissures.
The cerebral hemispheres are directly connected by three major interhemispheric fibers: the corpus callosum, the anterior commissure, and the hippocampal commissure. RA-GEF-1 (also termed Rapgef2) is a guanine nucleotide exchange factor responsible for sustained activation of Rap1. We previously reported anatomical defects of the major forebrain commissures in the adult dorsal telencephalon-specific RA-GEF-1 conditional knockout (cKO) mice. ⋯ Wheat germ agglutinin-conjugated horseradish peroxidase retrograde tracing verifies the agenesis of the anterior commissure in cKO mice, and DiI anterograde tracing confirms the deviation of the fibers from their original tract. As for the hippocampal commissure, agenesis and hypoplasia are observed in its dorsal and ventral parts, respectively. These results indicate the essential role of RA-GEF-1 in the proper formation of the cerebral midline commissures.
-
Neuroscience research · Nov 2011
Emotional face recognition, EMG response, and medial prefrontal activity in empathic behaviour.
One important aspect of empathy is a "resonance mechanism", which includes emotional cue detection, facial mimicry (measured by electromyography, EMG) and a specific cortical response. This study explored the convergence of these three measures of affective empathy. The twenty students who took part in the study were required to empathise with the situation by entering into the other person's situation. ⋯ Second, the MPFC was implicated in facial cue detection and the subsequent autonomic response because an impaired performance on both measures was observed when this brain area was inhibited. Third, this effect increased when negative-valenced stimuli (angry and fearful faces) were presented to the subjects. These results revealed a significant effect of the MPFC on both cue detection and facial mimicry that was distinctly related to different types of emotions.
-
Neuroscience research · Nov 2011
Detection of autoantibody against extracellular epitopes of N-methyl-D-aspartate receptor by cell-based assay.
The concept of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis, a severe, potentially lethal, treatment-responsive disorder, mediated by autoantibodies against NMDAR was proposed. Because paraneoplastic anti-NMDAR encephalitis has a better prognosis after tumor resection and immunotherapy, rapid quantitative systems for detecting functional autoantibodies against extracellular epitopes of NMDAR are necessary. To detect autoantibodies recognizing extracellular epitopes of NMDAR, we stably expressed mutant NMDAR that decreases Ca(2+) permeability on a heterologous cell surface without any antagonist. ⋯ Furthermore, we were able to express mutant GluRζ1(NR1, GluN1) subunit of NMDAR alone on the cell surface and obtained direct evidence of the presence of autoantibodies recognizing extracellular epitopes of GluRζ1 and the induction of internalization by autoantibodies in serum and CSF from patients. The specificity of on-cell Western analysis was improved at 37°C. The combination of this rapid quantitative assay using our on-cell western analysis, detailed analysis of extracellular epitopes of NMDAR, and internalization assay of NMDAR will be valuable for the diagnosis, evaluation of clinical treatments, and follow-up of anti-NMDAR encephalitis.