ABSTRACT
The ability to efficiently control charge and spin in the cuprate high-temperature superconductors is crucial for fundamental research and underpins technological development. Here, we explore the tunability of magnetism, superconductivity, and crystal structure in the stripe phase of the cuprate La[Formula: see text]Ba[Formula: see text]CuO[Formula: see text], with [Formula: see text] = 0.115 and 0.135, by employing temperature-dependent (down to 400 mK) muon-spin rotation and AC susceptibility, as well as X-ray scattering experiments under compressive uniaxial stress in the CuO[Formula: see text] plane. A sixfold increase of the three-dimensional (3D) superconducting critical temperature [Formula: see text] and a full recovery of the 3D phase coherence is observed in both samples with the application of extremely low uniaxial stress of [Formula: see text]0.1 GPa. This finding demonstrates the removal of the well-known 1/8-anomaly of cuprates by uniaxial stress. On the other hand, the spin-stripe order temperature as well as the magnetic fraction at 400 mK show only a modest decrease under stress. Moreover, the onset temperatures of 3D superconductivity and spin-stripe order are very similar in the large stress regime. However, strain produces an inhomogeneous suppression of the spin-stripe order at elevated temperatures. Namely, a substantial decrease of the magnetic volume fraction and a full suppression of the low-temperature tetragonal structure is found under stress, which is a necessary condition for the development of the 3D superconducting phase with optimal [Formula: see text]. Our results evidence a remarkable cooperation between the long-range static spin-stripe order and the underlying crystalline order with the three-dimensional fully coherent superconductivity. Overall, these results suggest that the stripe- and the SC order may have a common physical mechanism.
ABSTRACT
We present an in situ uniaxial pressure device optimized for small angle x-ray and neutron scattering experiments at low-temperatures and high magnetic fields. A stepper motor generates force, which is transmitted to the sample via a rod with an integrated transducer that continuously monitors the force. The device has been designed to generate forces up to 200 N in both compressive and tensile configurations, and a feedback control allows operating the system in a continuous-pressure mode as the temperature is changed. The uniaxial pressure device can be used for various instruments and multiple cryostats through simple and exchangeable adapters. It is compatible with multiple sample holders, which can be easily changed depending on the sample properties and the desired experiment and allow rapid sample changes.
ABSTRACT
The hydrolytic processes occurring at the surface of silicon nitride (Si3N4) bioceramic have been indicated as a powerful pathway to instantaneous inactivation of SARS-CoV-2 virus. However, the virus inactivation mechanisms promoted by Si3N4 remain yet to be elucidated. In this study, we provide evidence of the instantaneous damage incurred on the SARS-CoV-2 virus upon contact with Si3N4. We also emphasize the safety characteristics of Si3N4 for mammalian cells. Contact between the virions and micrometric Si3N4 particles immediately targeted a variety of viral molecules by inducing post-translational oxidative modifications of S-containing amino acids, nitration of the tyrosine residue in the spike receptor binding domain, and oxidation of RNA purines to form formamidopyrimidine. This structural damage in turn led to a reshuffling of the protein secondary structure. These clear fingerprints of viral structure modifications were linked to inhibition of viral functionality and infectivity. This study validates the notion that Si3N4 bioceramic is a safe and effective antiviral compound; and a primary antiviral candidate to replace the toxic and allergenic compounds presently used in contact with the human body and in long-term environmental sanitation.
ABSTRACT
We report muon spin rotation and magnetic susceptibility experiments on in-plane stress effects on the static spin-stripe order and superconductivity in the cuprate system La_{2-x}Ba_{x}CuO_{4} with x=0.115. An extremely low uniaxial stress of â¼0.1 GPa induces a substantial decrease in the magnetic volume fraction and a dramatic rise in the onset of 3D superconductivity, from â¼10 to 32 K; however, the onset of at-least-2D superconductivity is much less sensitive to stress. These results show not only that large-volume-fraction spin-stripe order is anticorrelated with 3D superconducting coherence but also that these states are energetically very finely balanced. Moreover, the onset temperatures of 3D superconductivity and spin-stripe order are very similar in the large stress regime. These results strongly suggest a similar pairing mechanism for spin-stripe order and the spatially modulated 2D and uniform 3D superconducting orders, imposing an important constraint on theoretical models.
ABSTRACT
We use resonant inelastic x-ray scattering to investigate charge-stripe correlations in La_{1.675}Eu_{0.2}Sr_{0.125}CuO_{4}. By differentiating elastic from inelastic scattering, it is demonstrated that charge-stripe correlations precede both the structural low-temperature tetragonal phase and the transport-defined pseudogap onset. The scattering peak amplitude from charge stripes decays approximately as T^{-2} towards our detection limit. The in-plane integrated intensity, however, remains roughly temperature independent. Therefore, although the incommensurability shows a remarkably large increase at high temperature, our results are interpreted via a single scattering constituent. In fact, direct comparison to other stripe-ordered compounds (La_{1.875}Ba_{0.125}CuO_{4}, La_{1.475}Nd_{0.4}Sr_{0.125}CuO_{4}, and La_{1.875}Sr_{0.125}CuO_{4}) suggests a roughly constant integrated scattering intensity across all these compounds. Our results therefore provide a unifying picture for the charge-stripe ordering in La-based cuprates. As charge correlations in La_{1.675}Eu_{0.2}Sr_{0.125}CuO_{4} extend beyond the low-temperature tetragonal and pseudogap phase, their emergence heralds a spontaneous symmetry breaking in this compound.
ABSTRACT
Bone structure and function are maintained by well-regulated bone metabolism and remodeling. Although the underlying molecular and cellular mechanisms are now being understood, physiological and pathological states of bone are still difficult to predict due to the complexity of intercellular signaling. We have now developed a novel in silico experimental platform, V-Bone, to integratively explore bone remodeling by linking complex microscopic molecular/cellular interactions to macroscopic tissue/organ adaptations. Mechano-biochemical couplings modeled in V-Bone relate bone adaptation to mechanical loading and reproduce metabolic bone diseases such as osteoporosis and osteopetrosis. V-Bone also enables in silico perturbation on a specific signaling molecule to observe bone metabolic dynamics over time. We also demonstrate that this platform provides a powerful way to predict in silico therapeutic effects of drugs against metabolic bone diseases. We anticipate that these in silico experiments will substantially accelerate research into bone metabolism and remodeling.
Subject(s)
Bone Remodeling/drug effects , Computer Simulation , Models, Biological , Osteopetrosis , Osteoporosis , Humans , Osteopetrosis/drug therapy , Osteopetrosis/metabolism , Osteopetrosis/pathology , Osteoporosis/drug therapy , Osteoporosis/metabolism , Osteoporosis/pathologyABSTRACT
OBJECTIVES: To describe the health information preferences in middle-aged Japanese workers based on health literacy (HL) levels and presence of medications. STUDY DESIGN: A cross-sectional study. METHODS: We performed a web-based questionnaire survey with Japanese workers aged below 60 years. HL was assessed using the total score of communicative skills (five items) and critical skills (four items) from the 14-item Health Literacy Scale. Regarding their health information preferences, participants were asked about the health information they wanted (four items), could easily understand (six items), or easily use (two items) and answered on a 4-point scale (strongly agree/agree/disagree/strongly disagree). The percentages of the affirmative responses (strongly agree or agree) were compared among tertiles based on the HL score. RESULTS: We obtained data from a total of 3387 volunteers, of whom 510 participants were on either antihypertensive, lipid-lowering, or antidiabetic drugs. Compared with the high HL and middle HL groups, low HL had fewer affirmative responses to most health information items. Health information items received 70% of affirmative responses even in the low HL level. They were visually shown by figures or pictures, highlighted by colors for important points, could be read in 1-2 min, and were accessed on the Internet, regardless of the presence of medications. Additionally, the explanation for mechanisms of medications or lifestyle to prevent or improve diseases showed high affinity in all HL levels, only for those on medications. CONCLUSIONS: This result generates a hypothesis that low HL individuals have a low interest in health information. Our data showed several possible forms of health information with high affinity based on HL levels that would help plan future population approaches.
Subject(s)
Consumer Behavior/statistics & numerical data , Consumer Health Information , Health Literacy/statistics & numerical data , Adult , Cross-Sectional Studies , Employment/statistics & numerical data , Female , Humans , Internet , Japan , Male , Middle Aged , Noncommunicable Diseases/prevention & control , Surveys and QuestionnairesABSTRACT
Organogenesis is a self-organizing process of multiple cells in three-dimensional (3D) space, where macroscopic tissue deformations are robustly regulated by multicellular autonomy. It is clear that this robust regulation requires cells to sense and modulate 3D tissue formation across different scales, but its underlying mechanisms are still unclear. To address this question, we developed a versatile computational model of 3D multicellular dynamics at single-cell resolution and combined it with the 3D culture system of pluripotent stem cell-derived optic-cup organoid. The complementary approach enabled quantitative prediction of morphogenesis and its corresponding verification and elucidated that the macroscopic 3D tissue deformation is fed back to individual cellular force generations via mechanosensing. We hereby conclude that mechanical force plays a key role as a feedback regulator to establish the robustness of organogenesis.
Subject(s)
Models, Theoretical , Morphogenesis , Organ Culture Techniques/methods , Organogenesis , Retina/cytology , Stress, Mechanical , HumansABSTRACT
KRAS mutations occur in 30-40% of all cases of human colorectal cancer (CRC). However, to date, specific therapeutic agents against KRAS-mutated CRC have not been developed. We previously described the generation of mouse models of colon cancer with and without Kras mutations (CDX2P-G22Cre;Apc(flox/flox); LSL-Kras(G12D) and CDX2P-G22Cre;Apc(flox/flox) mice, respectively). Here, the two mouse models were compared to identify candidate genes, which may represent novel therapeutic targets or predictive biomarkers. Differentially expressed genes in tumors from the two mouse models were identified using microarray analysis, and their expression was compared by quantitative reverse transcription-PCR (qRT-PCR) and immunohistochemical analyses in mouse tumors and surgical specimens of human CRC, with or without KRAS mutations, respectively. Furthermore, the functions of candidate genes were studied using human CRC cell lines. Microarray analysis of 34 000 transcripts resulted in the identification of 19 candidate genes. qRT-PCR analysis data showed that four of these candidate genes (Clps, Irx5, Bex1 and Rcan2) exhibited decreased expression in the Kras-mutated mouse model. The expression of the regulator of calcineurin 2 (RCAN2) was also observed to be lower in KRAS-mutated human CRC. Moreover, inhibitory function for cancer cell proliferation dependent on calcineurin was indicated with overexpression and short hairpin RNA knockdown of RCAN2 in human CRC cell lines. KRAS mutations in CRC lead to a decrease in RCAN2 expression, resulting in tumor proliferation due to derepression of calcineurin-nuclear factor of activated T cells (NFAT) signaling. Our findings suggest that calcineurin-NFAT signal may represent a novel molecular target for the treatment of KRAS-mutated CRC.
ABSTRACT
In the hole-doped cuprates, a small number of carriers suppresses antiferromagnetism and induces superconductivity. In the electron-doped cuprates, on the other hand, superconductivity appears only in a narrow window of high-doped Ce concentration after reduction annealing, and strong antiferromagnetic correlation persists in the superconducting phase. Recently, Pr(1.3-x)La0.7Ce(x)CuO4 (PLCCO) bulk single crystals annealed by a protect annealing method showed a high critical temperature of around 27 K for small Ce content down to 0.05. Here, by angle-resolved photoemission spectroscopy measurements of PLCCO crystals, we observed a sharp quasi-particle peak on the entire Fermi surface without signature of an antiferromagnetic pseudogap unlike all the previous work, indicating a dramatic reduction of antiferromagnetic correlation length and/or of magnetic moments. The superconducting state was found to extend over a wide electron concentration range. The present results fundamentally challenge the long-standing picture on the electronic structure in the electron-doped regime.
Subject(s)
Adenocarcinoma/diagnosis , Adenocarcinoma/pathology , Biopsy, Fine-Needle/adverse effects , Endosonography/adverse effects , Image-Guided Biopsy/adverse effects , Pancreatic Neoplasms/diagnosis , Pancreatic Neoplasms/pathology , Stomach Neoplasms/etiology , Stomach Neoplasms/pathology , Adenocarcinoma/surgery , Aged , Dilatation, Pathologic , Female , Gastrectomy , Humans , Neoplasm Invasiveness , Pancreatectomy , Pancreatic Ducts/pathology , Pancreatic Neoplasms/surgery , Stomach Neoplasms/surgery , Treatment OutcomeABSTRACT
BACKGROUND: The energy requirements of free-ranging marine mammals are challenging to measure due to cryptic and far-ranging feeding habits, but are important to quantify given the potential impacts of high-level predators on ecosystems. Given their large body size and carnivorous lifestyle, we would predict that northern elephant seals (Mirounga angustirostris) have elevated field metabolic rates (FMRs) that require high prey intake rates, especially during pregnancy. Disturbance associated with climate change or human activity is predicted to further elevate energy requirements due to an increase in locomotor costs required to accommodate a reduction in prey or time available to forage. In this study, we determined the FMRs, total energy requirements, and energy budgets of adult, female northern elephant seals. We also examined the impact of increased locomotor costs on foraging success in this species. RESULTS: Body size, time spent at sea and reproductive status strongly influenced FMR. During the short foraging migration, FMR averaged 90.1 (SE = 1.7) kJ kg(-1)d(-1) - only 36 % greater than predicted basal metabolic rate. During the long migration, when seals were pregnant, FMRs averaged 69.4 (±3.0) kJ kg(-1)d(-1) - values approaching those predicted to be necessary to support basal metabolism in mammals of this size. Low FMRs in pregnant seals were driven by hypometabolism coupled with a positive feedback loop between improving body condition and reduced flipper stroking frequency. In contrast, three additional seals carrying large, non-streamlined instrumentation saw a four-fold increase in energy partitioned toward locomotion, resulting in elevated FMRs and only half the mass gain of normally-swimming study animals. CONCLUSIONS: These results highlight the importance of keeping locomotion costs low for successful foraging in this species. In preparation for lactation and two fasting periods with high demands on energy reserves, migrating elephant seals utilize an economical foraging strategy whereby energy savings from reduced locomotion costs are shuttled towards somatic growth and fetal gestation. Remarkably, the energy requirements of this species, particularly during pregnancy, are 70-80 % lower than expected for mammalian carnivores, approaching or even falling below values predicted to be necessary to support basal metabolism in mammals of this size.
ABSTRACT
Differential cross sections of isoscalar and isovector spin-M1 (0(+)â1(+)) transitions are measured using high-energy-resolution proton inelastic scattering at E(p)=295 MeV on (24)Mg, (28)Si, (32)S, and (36)Ar at 0°-14°. The squared spin-M1 nuclear transition matrix elements are deduced from the measured differential cross sections by applying empirically determined unit cross sections based on the assumption of isospin symmetry. The ratios of the squared nuclear matrix elements accumulated up to E(x)=16 MeV compared to a shell-model prediction are 1.01(9) for isoscalar and 0.61(6) for isovector spin-M1 transitions, respectively. Thus, no quenching is observed for isoscalar spin-M1 transitions, while the matrix elements for isovector spin-M1 transitions are quenched by an amount comparable with the analogous Gamow-Teller transitions on those target nuclei.
Subject(s)
Herpes Zoster/drug therapy , Immunologic Memory/immunology , Lichenoid Eruptions/etiology , T-Lymphocytes/immunology , 2-Aminopurine/administration & dosage , 2-Aminopurine/analogs & derivatives , Antigens, CD/immunology , Antigens, Differentiation, T-Lymphocyte/immunology , Antiviral Agents/administration & dosage , Famciclovir , Herpes Zoster/immunology , Herpes Zoster/pathology , Humans , Lectins, C-Type/immunology , Lichenoid Eruptions/immunology , Lichenoid Eruptions/pathology , Male , Middle Aged , RecurrenceABSTRACT
BACKGROUND: We have previously reported a hybrid procedure that uses a combination of laparoscopic mobilization of the liver and subsequent hepatectomy under direct vision in living donor liver transplantation (LDLT). We present the details of this hybrid procedure and the outcomes of the procedure. METHODS: Between January 1997 and August 2014, 204 LDLTs were performed at Nagasaki University Hospital. Among them, 67 recent donors underwent hybrid donor hepatectomy. Forty-one donors underwent left hemihepatectomy, 25 underwent right hemihepatectomy, and 1 underwent posterior sectionectomy. First, an 8-cm subxiphoid midline incision was made; laparoscopic mobilization of the liver was then achieved with a hand-assist through the midline incision under the pneumoperitoneum. Thereafter, the incision was extended up to 12 cm for the right lobe and posterior sector graft and 10 cm left lobe graft procurement. Under direct vision, parenchymal transection was performed by means of the liver-hanging maneuver. The hybrid procedure for LDLT recipients was indicated only for selected cases with atrophic liver cirrhosis without a history of upper abdominal surgery, significant retroperitoneal collateral vessels, or hypertrophic change of the liver (n = 29). For total hepatectomy and splenectomy, the midline incision was sufficiently extended. RESULTS: All of the hybrid donor hepatectomies were completed without an extra subcostal incision. No significant differences were observed in the blood loss or length of the operation compared with conventional open procedures. All of the donors have returned to their preoperative activity level, with fewer wound-related complaints compared with those treated with the use of the conventional open procedure. In recipients treated with the hybrid procedure, no clinically relevant drawbacks were observed compared with the recipients treated with a regular Mercedes-Benz-type incision. CONCLUSIONS: Our hybrid procedure was safely conducted with the same quality as the conventional open procedure in both LDLT donors and recipients.
Subject(s)
Hepatectomy/methods , Laparoscopy/methods , Liver Transplantation , Living Donors , Tissue and Organ Harvesting/methods , Adult , Aged , Female , Humans , Liver Cirrhosis/pathology , Male , Middle Aged , SplenectomyABSTRACT
BACKGROUND: The aim of this study was to evaluate the influence of previous local treatment on the E-cadherin (E-cad) expression in cases of hepatocellular carcinoma (HCC) after living donor liver transplantation (LDLT) within the Milan criteria. METHODS: Seventy-four of 204 patients with HCC underwent LDLT between 1997 and 2014. Previous local treatment for HCC was performed for 121 lesions in 47 patients (47/74, 63.5%). Histological and immunohistochemical E-cad expression analyses were conducted on the basis of the whole-liver histological examination technique. RESULTS: The interval to LDLT after the initial and last treatments was 24 months (2-206) and 10.5 months (1-58), respectively. Preoperative imaging showed necrosis in 92 (92/121, 76.0%) lesions caused by the effects of local treatment, whereas the histological examinations revealed viable HCC cells in 22 (22/92, 23.9%) lesions, demonstrating well or moderate differentiation without vascular invasion. Immunohistochemically, the expression of E-cad was maintained in 17 viable (17/22, 77.3%) lesions. There were no signs of malignant transformation or sarcomatous changes in the HCCs treated with previous therapy. The recipients who maintained an E-cad expression in the lesion with local treatment showed no recurrence or distant metastasis after LDLT. CONCLUSIONS: HCC cells remained in approximately 20% of the evaluated lesions, even those exhibiting necrosis on imaging of the explanted cirrhotic liver. However, the expression of E-cad was maintained in most of these lesions. Furthermore, there were no significant differences in the rate of recurrence after LDLT between the patients who did and those did not receive previous local treatment for HCC.
Subject(s)
Cadherins/metabolism , Carcinoma, Hepatocellular/metabolism , Liver Neoplasms/metabolism , Adult , Aged , Carcinoma, Hepatocellular/pathology , Carcinoma, Hepatocellular/surgery , Female , Humans , Liver Neoplasms/pathology , Liver Neoplasms/surgery , Liver Transplantation/methods , Living Donors , Male , Middle Aged , Risk FactorsABSTRACT
PURPOSE: To estimate the feasibility and limitations of incomplete cytoreductive surgery and modern systemic chemotherapy in patients with synchronous peritoneal carcinomatosis from colorectal cancer and to identify risk factors for death and factors associated with the patient prognosis. METHODS: Sixty-five consecutive patients underwent surgery for synchronous peritoneal carcinomatosis from colorectal cancer at Hiroshima University, Japan between 1992 and 2012. The clinical, histological, and survival data were analyzed for independent risk factors and prognostic factors. The patients were retrospectively stratified into two groups according to the extent of surgery: complete cytoreductive surgery or incomplete cytoreductive surgery. RESULTS: The median survival times in the complete and incomplete cytoreductive surgery groups were 29.8 and 10.0 months, respectively. Receiving systemic chemotherapy alone was an independent risk factor for death in the incomplete cytoreductive surgery group (P < 0.001). Oxaliplatin and molecular-targeted drug (cetuximab or bevacizumab) therapies were also independent prognostic factors (P < 0.001), whereas irinotecan therapy was not a prognostic factor (P = 0.494). CONCLUSION: Oxaliplatin and molecular-targeted drug therapies improved the overall survival in patients undergoing incomplete cytoreductive surgery. Future trials for patients with synchronous peritoneal carcinomatosis from colorectal cancer should be undertaken, with patients stratified according to treatment with complete cytoreductive surgery or incomplete cytoreductive surgery with modern chemotherapy.
Subject(s)
Antineoplastic Agents/therapeutic use , Colorectal Neoplasms/therapy , Cytoreduction Surgical Procedures/methods , Molecular Targeted Therapy , Neoplasms, Multiple Primary , Organoplatinum Compounds/therapeutic use , Peritoneal Neoplasms/therapy , Aged , Colorectal Neoplasms/mortality , Combined Modality Therapy , Female , Follow-Up Studies , Humans , Male , Middle Aged , Oxaliplatin , Peritoneal Neoplasms/mortality , Prognosis , Retrospective Studies , Survival RateABSTRACT
BACKGROUND: The survival of human immunodeficiency virus (HIV)-infected patients has significantly improved since the introduction of antiretroviral therapy (ART). However, the mortality due to hepatitis C virus (HCV)-related liver disease has not been reduced in HIV/HCV-coinfected patients, and HCV has recently become the most significant cause of death in HIV/HCV-coinfected patients. Liver transplantation might be one of the treatments of choice in such cases, but it is very difficult to evaluate the immune status of these patients due to ART, anti-HCV treatment, and HIV-related immunocompromised state. AIM: The aim of this study was to evaluate the immune status in HIV/HCV-coinfected patients using the Cylex ImmuKnow assay, which was designed to monitor the global immune status by measuring the adenosine triphosphate (ATP) levels produced by activated CD4+ T cells. METHODS: Twenty-eight HIV/HCV-coinfected patients were included in this study. We evaluated their immune activity using the ImmuKnow assay, and compared the data with those of HCV mono-infected patients indicated for liver transplantation as well as healthy controls. RESULTS: The ATP levels of HIV/HCV-coinfected patients were significantly higher than those of HCV mono-infected liver transplant recipients (P < .001), and were significantly lower than those of healthy controls (P = .001). CONCLUSION: The ImmuKnow assay was considered to be a useful tool to evaluate the immune status of HIV/HCV-coinfected patients.
Subject(s)
HIV Infections/immunology , Hepatitis C/immunology , Adenosine Triphosphate/metabolism , HIV Infections/complications , HIV Infections/metabolism , Hepatitis C/complications , Hepatitis C/metabolism , HumansABSTRACT
Gamow-Teller (GT) transitions in atomic nuclei are sensitive to both nuclear shell structure and effective residual interactions. The nuclear GT excitations were studied for the mass number A = 42, 46, 50, and 54 "f-shell" nuclei in ((3)He, t) charge-exchange reactions. In the (42)Ca â (42)Sc reaction, most of the GT strength is concentrated in the lowest excited state at 0.6 MeV, suggesting the existence of a low-energy GT phonon excitation. As A increases, a high-energy GT phonon excitation develops in the 6-11 MeV region. In the (54)Fe â (54)Co reaction, the high-energy GT phonon excitation mainly carries the GT strength. The existence of these two GT phonon excitations are attributed to the 2 fermionic degrees of freedom in nuclei.
ABSTRACT
Cyclin-dependent kinase 5 (Cdk5) is a serine/threonine kinase, and its kinase activity is dependent upon its association with either of the activating subunits p35 or p39, which are mainly expressed in neurons. We previously reported that Cdk5 knockout (KO) mice exhibit perinatal lethality, defective neuronal migration, and abnormal positioning of neurons in the facial motor nucleus and inferior olive in the hindbrain and Purkinje cells (PCs) in the cerebellum. In this study, we focused on the analysis of the role of Cdk5 in cerebellar development. For this purpose we generated midbrain-hindbrain-specific Cdk5 conditional knockout (MHB-Cdk5 KO) mice because the cerebellum develops postnatally, whereas Cdk5 KO mice die perinatally. Histological analysis of the MHB-Cdk5 KO mice revealed a significant size reduction of the cerebellum. In addition, profound disturbance of inward migration of granule cells (GC) was observed in the developing cerebellum. A normal dendritic development of the Purkinje cells (PCs) was disturbed in MHB-Cdk5 KO mice. Cultured Cdk5-null PCs showed similar dendritic abnormalities. These results indicate that Cdk5/p35 plays an important role in neuronal migration of PCs and GCs and dendrite formation of PCs in cerebellar development.