Eiko Uezu

Effects of short nap and exercise on elderly people having difficulty in sleeping.

The purpose of the present study was to examine the effects of short nap and exercise on the sleep quality of elderly people who reported difficulty in sleeping. ‘Interventions’ such as short nap after lunch and moderate‐intensity exercise in the evening were carried out for 4 weeks. After the ‘interventions’, wake time after sleep onset significantly decreased and sleep efficiency significantly increased, which showed that sleep quality was improved. The frequency of nodding in the evening significantly decreased. These results demonstrated that the proper awakening maintenance in the evening was effective in improving sleep quality. After the ‘intervention’, mental health was also improved with improving sleep quality.

Short naps and exercise improve sleep quality and mental health in the elderly

Abstract The effects of short naps and exercise on the sleep quality and mental health of elderly people was investigated. ‘Interventions’ by short naps after lunch and exercise of moderate intensity in the evening were carried out for 4 weeks. After the ‘intervention’, awake time after sleep onset decreased significantly and sleep efficiency increased significantly, demonstrating that sleep quality had improved. Also, the frequency of nodding in the evening decreased significantly. These results demonstrate that proper awakening maintenance in the evening was effective in improving sleep quality. After the ‘intervention’, mental health and volition and physical health had also improved with improving sleep quality.

Active transport pumps of HVA and DOPAC in dopaminergic nerve terminals.

The effect of the membrane potential on the efflux of HVA and DOPAC from DA neurons was studied in anesthetized (1% halothane in gas mixture of 70% N2O and 30% O2) cats. Extracellular DA, HVA and DOPAC were measured continuously from the putamen, the hypothalamus, the thalamus, the raphe nuclei and the cortex using brain microdialysis technique combined with HPLC-ED monoamine measurements. HVA and DOPAC concentrations were highest in the putamen and lowest in the cerebral cortex. Extracellular HVA levels exceed those of the DOPAC. Increases in the extracellular potassium from 4 to 120 mM invariably produced decreases of the extracellular HVA and DOPAC in all the tested brain regions. These decreases were inversely proportional to the extracellular potassium concentration. Thus, it is concluded that the HVA and the DOPAC are extruded from inside the cell to the extracellular space by active mechanisms of transport similar to that reported for 5-HIAA in serotonergic neurons.

Effects of Hemerocallis on sleep in mice

Abstract Freeze‐dried flowers of the Akinowasuregusa (Hemerocallis fulva L. var. sempervirona M. Hotta), a Hemerocallis genus of the lily family, were fed to C57BL strain mice. The slow wave sleep and paradoxical sleep of the Hemerocallis‐treated group increased during the dark period. The differences between the control group and the Hemerocallis‐treated group were significant (P < 0.05). The Hemerocallis feeding did not cause a change in sleep time during the light period. As a result, there was no significant change in the sleep‐time percentage over a 24‐h period.

Efflux of 5-HIAA form 5-HT neurons: A membrane potential-dependent process

The effect of the membrane potential on the efflux of 5-HIAA from 5-HT neurons was studied in anesthetized (halothane: 1% in gas mixture of N2O: 70% and O2: 30%) cats. The endogenous 5-HT and its metabolite 5-HIAA were measured continuously from the cortex, the thalamus, the hypothalamus and the raphe nuclei using brain microdialysis technique combined with HPLC-ED monoamine measurements. Membrane potential variations were induced by changing the extracellular concentration of potassium through the microdialysis membrane. The levels of the extracellular 5-HIAA varied according to the different regions of the brain, being highest in the hypothalamus and lowest in the cerebral cortex. Increases in the extracellular potassium from 4 to 120 mM invariably produced a decrease of the extracellular 5-HIAA in all the tested brain regions. This decrease was inversely proportional to the logarithm of extracellular potassium concentration. Thus, it is postulated that the 5-HIAA is moved from inside the cell to extracellular space by an active mechanism of transport electrically coupled to the membrane potential.

Survey of sleep-health and lifestyle of the elderly in Okinawa.

A total of 788 people (aged from 60 to 93 years) living in the Okinawa prefecture, renowned for the long life expectancy of its citizens, were randomly chosen as subjects. A questionnaire based on lifestyle and sleep‐health was distributed. Following this, subjects were chosen in groups of nine from the good sleep‐health group and then from the poor sleep‐health group based on the results of the survey; their physical activities were then recorded using actigraphs for 1 week. This study suggested that lifestyle, such as exercise, walking and short naps, occupies an important position in the maintenance and improvement of sleep‐health. It also verified the reliability of the sleep‐health risk index and the questionnaire.

Effects of dietary phosphatidylcholine on memory in memory deficient mice with low brain acetylcholine concentration.

Data concerning the effect of phosphatidylcholine (PCh) administration on the improvement of memory in senile dementia of Alzheimer type are inconsistent, probably due to the different conditions under which studies were conducted. Animal studies provide a good model, but data on this is limited. We studied the effect of PCh on memory in memory deficient mice (Dull mice) with low brain acetylcholine (ACh) concentration and normal mice. Mice were fed 24% casein diet (control) or this diet supplemented with 2 or 8% egg yolk PCh from gestation (Experiment 1) and after weaning (Experiment 2). Memory acquisition and retention were studied by step-down type passive avoidance performance at 8 and 10 weeks old, respectively. Control group of Dull mice had poorer memories than that of the normal mice in Experiments 1 and 2. On the 2% PCh diet, Dull mice improved memory acquisition and retention in Experiment 1 and retention in Experiment 2. On the 8% PCh diet in Dull mice there was improvement of memory and retention in Experiment 1, but no effect was observed in Experiment 2 (P > 0.05). In the normal mice, the 2% PCh diet did not affect memory acquisition and retention, however on the 8% PCh diet, there was no or adverse effect. These results suggest that dietary supplementation of egg yolk PCh improves memory of Dull mice, particularly when given from gestation and that the 2% PCh diet elicits better response than the 8% PCh diet.

Effects of dietary nucleoside-nucleotide mixture on memory in aged and young memory deficient mice

Intestinal mucosa, bone marrow hematopoietic cells and brain have limited capacity for the de novo synthesis of nucleosides (NSs) and nucleotides (NTs). Whereas the role of dietary NS and NT in the former two tissues is known, it is not known in the brain. Therefore we studied the effect of dietary NS and NT mixture on memory in aged mice (Experiment 1) and young memory deficient mice (Experiment 2). Memory retention was studied by step-through type passive avoidance performance (maximum 180 seconds). In Experiment 1 aged (7 month old) senescence accelerated mice (SAM) were fed 20% casein diet (control) or this diet supplemented with 0.5% NS/NT mixture for 12 weeks. Memory was studied 1, 2 and 3 days after the electric shock (punishment). In Experiment 2, young (1 month old) memory deficient mice (Dull mice) and normal mice (ddY mice) were fed the same diets as those in Experiment 1 for 12 weeks. Memory retention was studied 1 and 3 days after the punishment. In the aged SAM the average time of avoidance and also the percentages of successful memory 2 and 3 days after the punishment were significantly higher in the NS/NT diet group than the control diet group (P < 0.05). In the Dull mice percentage of successful memory was higher in the NS/NT diet group than in the control group 3 days after the punishment, however, such an effect was not observed in the normal mice. These results suggest that insufficient endogenous supply of NSs and NTs may be responsible for the factor of memory deficiency with aging or of genetical memory deficiency, which can be improved by the dietary administration of NSs and NTs.

H+-ATPase and transport of DOPAC, HVA, and 5-HIAA in monoamine neurons

The effects of N-methylmaleimide (N-MtM), a vacuolar H(+)-ATPase inhibitor, were evaluated in the putamen of the cat to study the in vivo transport mechanisms of dopamine (DA), 5-hydroxytryptamine (5-HT), and their metabolites 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and 5-hydroxyindolacetic acid (5-HIAA), using the brain focal microdialysis technique combined with HPLC. The addition of N-MtM to the perfusate altered invariably the flux of the DOPAC, HVA, and 5-HIAA in a similar pattern, resulting in a decrease of the extracellular levels of such metabolites, its extent being N-MtM concentration dependent, thus indicating that the mechanism(s) of such a decrease is (are) related most likely to decreased transport from the intracellular to the extracellular space as the consequence of the inhibition of the vacuolar H(+)-ATPase of DA and 5-HT neurons by the N-MtM. Furthermore, N-MtM masked the release of DA and 5-HT produced by KCl 120 mmol/l. Indeed, N-MtM increased the extracellular levels of such transmitters to values exceeding 4 to 6 times of those produced by KCl 120 mmol/l alone, which suggests that vacuolar H(+)-ATPase is probably involved also in the retention and/or reuptake process of DA and 5-HT.