Keita Tsujimura

Rett syndrome (RTT) is a severe neurological disorder, with impaired brain development caused by mutations in MECP2; however, the underlying mechanism remains elusive. We know from previous work that MeCP2 facilitates the processing of a specific microRNA, miR-199a, by associating with the Drosha complex to regulate neuronal functions. Here, we show that the MeCP2/miR-199a axis regulates neural stem/precursor cell (NS/PC) differentiation. A shift occurs from neuronal to astrocytic differentiatio

Proper dendritic elaboration of neurons is critical for the formation of functional circuits during brain development. Defects in dendrite morphogenesis are associated with neuropsychiatric disorders, and microRNAs are emerging as regulators of aspects of neuronal maturation such as axonal and dendritic growth, spine formation, and synaptogenesis. Here, we show that miR-214 plays a pivotal role in the regulation of dendritic development. Overexpression of miR-214 increased dendrite size and comp

Proper brain development requires the precise coordination and orchestration of various molecular and cellular processes and dysregulation of these processes can lead to neurological diseases. In the past decades, post-transcriptional regulation of gene expression has been shown to contribute to various aspects of brain development and function in the central nervous system. MicroRNAs (miRNAs), short non-coding RNAs, are emerging as crucial players in post-transcriptional gene regulation in a va

Rett syndrome (RTT) is a severe progressive neurodevelopmental disorder characterized by various neurological symptoms. Almost all RTT cases are caused by mutations in the X-linked methyl-CpG-binding protein 2 ( MeCP2 ) gene, and several mouse models have been established to understand the disease. However, the neuroanatomical abnormalities in each brain region of RTT mouse models have not been fully understood. Here, we investigated the global and local neuroanatomy of the Mecp2 gene-deleted RT

Proper development and function of the central nervous system require precise regulation of gene expression. MicroRNAs (miRNAs), a group of small non-coding RNAs that can negatively regulate gene expression at the post-transcriptional level, are critical regulators of neuronal development, and dysregulation of microRNAs has been implicated in various neurological disorders. Changes in microRNA expression and repertoire are related to the emergence of social and behavioral variations in closely r

Autism spectrum disorder is a neurodevelopmental condition characterized by reduced social communication and repetitive behaviors. Altered neurogenesis, including disturbed neuronal migration, has been implicated in autism spectrum disorder. Using diffusion MRI, we previously identified neuronal migration pathways in the human fetal brain and hypothesized that similar pathways persist into adulthood, with differences in volume and microstructural characteristics between individuals with autism s

One of the great advantages of fetal heart screening using the 3 vessels and trachea (3VT) view is to acquire intra thoracic information especially of the trachea. We illustrate this by describing 3 cases of double aortic arch (DAA) detected in low risk pregnancies. CASE 1. At 18 weeks gestation, we suspected a vascular ring, indicated by the U sign in the 3VT view. At 25 weeks, we found in addition, a narrowing of the left aortic arch (LAA). The fetus was diagnosed with DAA with a dominant righ

We show 2 cases of TAPVD detected in routine screening for fetal cardiac malformations. Case 1: A 32-year-old woman, G1P1, was screened at 19 weeks. An abnormal vessel was detected between the left atrium (LA) and descending aorta (dAo). Color Doppler demonstrated a connection between the vessel and the right and left pulmonary veins (PVs), indicative of TAPVD. A detailed scan at a tertiary care center revealed that the vessel was connected to the supra vena cava (SVC), leading to a diagnosis of

Vascular ring is an aortic arch anomaly. The trachea and esophagus are entrapped by the abnormal aortic arch vessels. Symptoms are breathing and swallowing difficulties, and some cases have severe findings of tracheomalacia. It is extremely difficult to diagnose in the postnatal period because of nonspecific symptoms. On the other hand, in the fetal period, it is easier to check for aortic arch anomaly by use of the three-vessels and trachea (3VT) view. We illustrate the importance of the 3VT vi