Conserved functional control, but distinct regulation, of cell proliferation in rice and Arabidopsis leaves revealed by comparative analysis of GRF-INTERACTING FACTOR 1 orthologs.

Regulation of cell proliferation is crucial for establishing the shape of plant leaves. We have identified MAKIBA3 (MKB3), a loss-of-function mutant of which exhibits a narrowed- and rolled-leaf phenotype in rice. MKB3 was found to be an ortholog of Arabidopsis ANGUSTIFOLIA3 (AN3), which positively regulates cell proliferation. The reduced leaf size of mkb3 plants with enlarged cells and the increased size of MKB3-overexpressing leaves with normal-sized cells indicate that MKB3 is a positive regulator of leaf proliferation and that mkb3 mutation triggers a compensation syndrome, as does Arabidopsis an3 Expression analysis revealed that MKB3 is predominantly expressed on the epidermis of leaf primordia, which is different from the location of AN3 A protein movement assay demonstrated that MKB3 moves from an MKB3-expressing domain to a non-expressing domain, which is required for normal leaf development. Our results suggest that rice MKB3 and Arabidopsis AN3 have conserved functions and effects on leaf development. However, the expression pattern of MKB3 and direction of protein movement are different between rice and Arabidopsis, which might reflect differences in leaf primordia development in these two species.

Neurocognitive profile of euthymic Japanese patients with bipolar disorder.

AIM: Neurocognitive impairment is one of the core symptoms of bipolar disorder (BD). The MATRICS Cognitive Consensus Battery (MCCB) is a potential consensus assessment tool to evaluate cognitive function in patients with BD. Here, we report on cognitive deficits evaluated using the MCCB Japanese version (MCCB-J) in euthymic Japanese patients with BD, and compare them with scores in previous studies. METHODS: We compared neurocognitive function in 25 patients with euthymic BD and 53 healthy controls (HC). Additionally, we searched all available databases for studies that have evaluated cognitive function in BD using the MCCB, and conducted a meta-analysis. RESULTS: Canonical discriminant analysis revealed significant differences in MCCB-J domain scores between BD and HC. Patients with BD performed significantly worse on visual learning, social cognition, speed of processing, and MCCB composite scores. Our meta-analysis revealed that patients with BD performed worse than HC, as reflected by MCCB composite scores and scores on all seven cognitive domains. However, there are differences in the cognitive deficits identified in previous studies compared with our participants, particularly social cognition. CONCLUSION: As reported in previous studies, neurocognitive deficits were observed in Japanese euthymic BD patients assessed using the MCCB-J. Further study is needed to clarify whether differences in social cognition between this study and previous studies are a result of coping mechanisms for social settings in Japanese populations.

Preattentive dysfunction in patients with bipolar disorder as revealed by the pitch-mismatch negativity: a magnetoencephalography (MEG) study.

OBJECTIVES: Mismatch negativity (MMN) and its magnetic counterpart (MMNm) are thought to reflect an automatic process that detects a difference between an incoming stimulus and the sensory memory trace of preceding stimuli. In patients with schizophrenia, an attenuation of the MMN/MMNm amplitude has been repeatedly reported. Heschl's gyrus (HG) is one of the major generators of MMN and the functional alteration of HG has been reported in patients with bipolar disorder. The present study investigated the pitch-MMNm in patients with bipolar disorder using whole-head 306-ch magnetoencephalography (MEG). METHODS: Twenty-two patients and 22 healthy controls participated in this study. Subjects were presented with two types of auditory stimulus sequences. One consisted of 1,000 Hz standards (probability = 90%) and 1,200 Hz deviants (probability = 10%), and the other consisted of 1,000 Hz standards (90%) and 1,200 Hz deviants (10%). These two tasks were each performed twice. Event-related brain responses to standard tones were subtracted from responses to deviant tones. RESULTS: Patients with bipolar disorder showed a significant bilateral reduction in magnetic global field power (mGFP) amplitudes (p = 0.02) and dipole moments of the MMNm (p = 0.04) compared with healthy controls. Patients with admission experience showed significantly reduced mGFP amplitudes of MMNm compared with patients without admission experience (p = 0.004). Additionally, patients with more severe manic symptoms had smaller mGFP amplitudes of MMNm (ρ = -0.50, p = 0.05). CONCLUSIONS: The results of this study suggest that patients with bipolar disorder may exhibit preattentive auditory dysfunction indexed by reduced pitch-MMNm responses. Pitch-MMNm could be a potential trait marker reflecting the global severity of bipolar disorder.