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K Hikishima,
K Sawada,
A Y Murayama,
Y Komaki,
K Kawai,
N Sato,
T Inoue,
T Itoh,
S Momoshima,
A Iriki,
H J Okano,
E Sasaki,
H Okano
[show abstract]
[hide abstract]
ABSTRACT: The developmental anatomy of the brain is largely directed by neural-based cues. Despite this knowledge, the developmental trajectory of the primate brain has not yet been fully characterized. To realize this goal, the advance in noninvasive imaging methods and new brain atlases are essential. The common marmoset (Callithrix jacchus), a small New World primate, is widely used in neuroscience research. The recent introduction of transgenic techniques has enabled the marmoset to be used as a genetically modifiable primate model for brain development. Here, a magnetic resonance (MR) histology technique involving the use of ultra-high-resolution ex vivo magnetic resonance imaging (MRI) was performed to identify the developmental anatomy of the marmoset brain at different time points from gestational week 8 (GW8) through to birth. The data allowed the generation of a multidimensional atlas of brain structures at different developmental stages. Furthermore, in utero MRI techniques were developed to noninvasively monitor brain development during the embryonic and fetal stages. The multidimensional atlas and the MRI tools developed herein are anticipated to further our understanding of the developing primate brain.
Neuroscience 10/2012; · 3.38 Impact Factor
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K Hikishima,
M M Quallo,
Y Komaki,
M Yamada,
K Kawai,
S Momoshima,
H J Okano,
E Sasaki,
N Tamaoki,
R N Lemon,
A Iriki,
H Okano
[show abstract]
[hide abstract]
ABSTRACT: Advanced magnetic resonance (MR) neuroimaging analysis techniques based on voxel-wise statistics, such as voxel-based morphometry (VBM) and functional MRI, are widely applied to cognitive brain research in both human subjects and in non-human primates. Recent developments in imaging have enabled the evaluation of smaller animal models with sufficient spatial resolution. The common marmoset (Callithrix jacchus), a small New World primate species, has been widely used in neuroscience research, to which voxel-wise statistics could be extended with a species-specific brain template. Here, we report, for the first time, a tissue-segmented, population-averaged standard template of the common marmoset brain. This template was created by using anatomical T(1)-weighted images from 22 adult marmosets with a high-resolution isotropic voxel size of (0.2 mm)(3) at 7-Tesla and DARTEL algorithm in SPM8. Whole brain templates are available at International Neuroinformatics Japan Node website, http://brainatlas.brain.riken.jp/marmoset/.
NeuroImage 10/2010; 54(4):2741-9. · 5.89 Impact Factor
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H Hashimoto,
T Arai,
A Mori,
K Kawai, K Hikishima,
Y Ohnishi,
T Eto,
M Ito,
K Hioki,
R Suzuki, [......],
M Saito,
Y Ueyama,
H Okano,
T Yamauchi,
N Kubota,
K Ueki,
K Tobe,
N Tamaoki,
T Kadowaki,
K Kosaka
[show abstract]
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ABSTRACT: Current Japanese and American diets and Japanese diet immediately after the War were converted to laboratory animal diets. As a result, current laboratory animal diet (CA-1, CLEA) unexpectedly resembled the diet of Japanese after the War. This is considered to result in an under-evaluation of diabetes research using laboratory animals at present. Therefore, changes in insulin signals caused by current Japanese and American diets were examined using IRS-2 deficient mice ( IRS2(-/-) mice) and mechanisms of aggravation of type 2 diabetes due to modern diets were examined. IRS2(-/-) mice at 6 weeks of age were divided into three groups: Japanese diet (Jd) group, American diet (Ad) group and CA-1 diet [regular diet (Rd)] group. Each diet was given to the dams from 7 days before delivery. When the IRS2(-/-) mice reached 6 weeks of age, the glucose tolerance test (GTT), insulin tolerance test (ITT) and organ sampling were performed. The sampled organs and white adipose tissue were used for analysis of RNA, enzyme activity and tissues. In GTT and ITT, the Ad group showed worse glucose tolerance and insulin resistance than the Rd group. Impaired glucose tolerance of the Jd group was the same as that of the Rd group, but insulin resistance was worse than in the Rd group. These results were caused an increase in fat accumulation and adipocytes in the peritoneal cavity by lipogenic enzyme activity in the liver and muscle, and the increase in TNFalpha of hypertrophic adipocyte origin further aggravated insulin resistance and the increase in resistin also aggravated the impaired glucose tolerance, leading to aggravation of type 2 diabetes. The Japanese and American diets given to the IRS2(-/-) mice, which we developed, showed abnormal findings in some IRS2(-/-) mice but inhibited excessive reactions of insulin signals as diets used in ordinary nutritional management.
Experimental and Clinical Endocrinology & Diabetes 08/2009; 117(10):577-86. · 1.69 Impact Factor
