EEG resting-state networks in Alzheimer’s disease associated with clinical symptoms

Alzheimer’s disease (AD) is a progressive neuropsychiatric disease affecting many elderly people and is characterized by progressive cognitive impairment of memory, visuospatial, and executive functions. As the elderly population is growing, the number of AD patients is increasing considerably. There is currently growing interest in determining AD’s cognitive dysfunction markers. We used exact low-resolution-brain-electromagnetic-tomography independent-component-analysis (eLORETA-ICA) to assess activities of five electroencephalography resting-state-networks (EEG-RSNs) in 90 drug-free AD patients and 11 drug-free patients with mild-cognitive-impairment due to AD (ADMCI). Compared to 147 healthy subjects, the AD/ADMCI patients showed significantly decreased activities in the memory network and occipital alpha activity, where the age difference between the AD/ADMCI and healthy groups was corrected by linear regression analysis. Furthermore, the age-corrected EEG-RSN activities showed correlations with cognitive function test scores in AD/ADMCI. In particular, decreased memory network activity showed correlations with worse total cognitive scores for both Mini-Mental-State-Examination (MMSE) and Alzheimer’s Disease-Assessment-Scale-cognitive-component-Japanese version (ADAS-J cog) including worse sub-scores for orientation, registration, repetition, word recognition and ideational praxis. Our results indicate that AD affects specific EEG-RSNs and deteriorated network activity causes symptoms. Overall, eLORETA-ICA is a useful, non-invasive tool for assessing EEG-functional-network activities and provides better understanding of the neurophysiological mechanisms underlying the disease

Different Characteristics of Cognitive Impairment in Elderly Schizophrenia and Alzheimer's Disease in the Mild Cognitive Impairment Stage

We compared indices of the revised version of the Wechsler Memory Scale (WMS-R) and scaled scores of the five subtests of the revised version of the Wechsler Adult Intelligence Scale (WAIS-R) in 30 elderly schizophrenia (ES) patients and 25 Alzheimer's disease (AD) patients in the amnestic mild cognitive impairment (aMCI) stage (AD-aMCI). In the WMS-R, attention/concentration was rated lower and delayed recall was rated higher in ES than in AD-aMCI, although general memory was comparable in the two groups. In WAIS-R, digit symbol substitution, similarity, picture completion, and block design scores were significantly lower in ES than in AD-aMCI, but the information scores were comparable between the two groups. Delayed recall and forgetfulness were less impaired, and attention, working memory and executive function were more impaired in ES than in AD-aMCI. These results should help clinicians to distinguish ES combined with AD-aMCI from ES alone

Developmental Responses of 2-cell Embryos to Oxygen Tension and Bovine Serum Albumin in Wistar Rats

To improve rat embryo culture conditions, responses of Wistar 2-cell embryos from 2 breeders to oxygen tension (5 vs. 20%) and bovine serum albumin (BSA) (0 vs. 3 mg/ml) were examined using rat 1-cell embryo culture medium (mR1ECM). Supplementation of 3 mg/ml BSA significantly stimulated and accelerated development to the blastocyst and expanded blastocyst stages during 72 and 96 hr culture, while reduced oxygen tension stimulated cell division. Fetus development after transfer of blastocysts obtained from 72 hr culture under 5% O2 with BSA was significantly higher than those cultured under atmospheric oxygen without BSA. However, the nuclear numbers of in vitro cultured blastocysts and fetus development after embryo transfer were still significantly lower than in vivo developed blastocysts, indicating the current culture condition is still suboptimal

Application of assisted reproductive technologies (ARTs) for radiobiological research

In radiation biology, experiments using animals are inevitable for understanding radiation effects at whole body level. Especially, use of genetically modified (GM) mice in radiation biology has been explosively increased in the last two decades, and an efficient system for maintenance of these animals has become a crucial issue in many radiobiological research institutes. In the National Institute of Radiological Sciences, the Advanced Animal Research Section has been collaborating with many research groups to facilitate whole animal experiments by application of assisted reproductive technologies (ARTs). The ARTs applicable to radiation research includes (1) production of new radiosensitve GM animals, (2) short and long term cryopreservation of embryos, (3) synchronous production of large number of animals, (4) domestic and international shipping of animals by way of cryopreserved embryos, and (5) cleaning of animals infected with various pathogens. An example of practical application of ARTs is simultaneous production of large animal colony by in vitro fertilization-embryo transfer (IVF-ET) system. This technique fits well for reproduction of GM mice, such as gpt-delta transgenic mice and aprt (adenine phosphorribosyltransferase) heterozygous mice used frequently for investigating radiation-induces mutagenesis in various tissues. Because of infertility derived from behavioral defect in aprt deficient homozygous (-/-) animals, they have to be bred in the colony of the heterozygous (+/-) and wild type (+/+) parents. However, maintenance of +/- animals requires laborious maintenance of both +/- and +/+ mice followed by genotyping. By application of IVF-ET to +/+ females and only two -/- males, we successfully obtained large stock of +/- aprt embryos (>500). These embryos were cryopreserved and, upon request, predetermined number of animals can be supplied without genotyping, resulting in maintenance of animals less expensively, less laboriously and more efficiently than conventional methods. Although we found some limitations in ARTs for practical application, we are currently making effort to improve our ARTs further for radiation research.13th International Congress of Radiation Researc

Neuropsychiatric Symptoms in Patients with Idiopathic Normal Pressure Hydrocephalus

Objective: To clarify the characteristics of neuropsychiatric symptoms in patients with idiopathic normal pressure hydrocephalus (iNPH)