Association between napping and cognitive impairment: A systematic review and meta-analysis.

STUDY OBJECTIVES: Increasing evidence suggests that napping is associated with cognitive impairment and dementia, but the conclusions are inconsistent. Moreover, the extent of the risk is uncertain. We therefore conducted a systematic review and meta-analysis to quantify the connection between napping and cognitive impairment. METHODS: We performed a systematic search of PubMed, EMBASE, Web of Science, and Cochrane Library for studies that were published up to June 2023, and assessed associations between napping and cognitive impairment. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated as the effect sizes for all studies. Heterogeneity and potential publication biases were assessed. RESULTS: A total of 4535 papers were retrieved, with 20 reports assessing the relationships between napping and cognitive impairment. Pooled analysis indicated that napping was associated with dementia (OR = 1.14; 95% CI: 1.07-1.21). Importantly, we found that those napping longer than 30, 45, and 60 min/day were 35%, 41%, and 40%, respectively, more likely to have an increased risk of cognitive impairment (30 min: OR = 1.35; 95% CI: 1.24-1.48; 45 min: OR = 1.41; 95% CI: 1.27-1.58; 60 min: OR = 1.40; 95% CI: 1.26-1.56). North America and Europe showed that associations existed between napping and cognitive impairment (North America: OR = 1.15; 95% CI: 1.04-1.27; Europe: OR = 1.13; 95% CI: 1.08-1.18). CONCLUSIONS: This meta-analysis indicated associations between long napping durations and cognitive impairment or dementia, suggesting that longer napping might be a potential risk factor of adverse cognitive outcomes.

Comparison of Microbial Diversity and Composition in Jejunum and Colon of the Alcohol-dependent Rats.

Alcohol dependence is a global public health problem, yet the mechanisms of alcohol dependence are incompletely understood. The traditional view has been that ethanol alters various neurotransmitters and their receptors in the brain and causes the addiction. However, an increasing amount of experimental evidence suggests that gut microbiota also influence brain functions via gut-to-brain interactions, and may therefore induce the development of alcohol use disorders. In this study, a rat model of alcohol dependence and withdrawal was employed, the gut microbiota composition was analyzed by high-throughput 16S rRNA gene sequencing, and the metagenome function was predicted by PICRUSt software. The results suggested that chronic alcohol consumption did not significantly alter the diversity and richness of gut microbiota in the jejunum and colon, but rather markedly changed the microbiota composition structure in the colon. The phyla Bacteroidetes and eight genera including Bacteroidales S24-7, Ruminococcaceae, Parabacteroides, Butyricimonas, et al were drastically increased, however the genus Lactobacillus and gauvreauii in the colon were significantly decreased in the alcohol dependence group compared with the withdrawal and control groups. The microbial functional prediction analysis revealed that the proportions of amino acid metabolism, polyketide sugar unit biosynthesis and peroxisome were significantly increased in the AD group. This study demonstrated that chronic alcohol consumption has a dramatic effect on the microbiota composition structure in the colon but few effects on the jejunum. Inducement of colonic microbiota dysbiosis due to alcohol abuse seems to be a factor of alcohol dependence, which suggests that modulating colonic microbiota composition might be a potentially new target for treating alcohol addiction.

Effects of aminooxyacetic acid on the learning and memory ability and its possible mechanism in rats with chronic alcoholism / 中国应用生理学杂志

OBJECTIVE@#To investigate the effects of aminooxyacetic acid (AOAA) on learning and memory ability and possible mechanisms in rats with chronic alcoholism.@*METHODS@#Sixty SD male rats were randomly divided into three groups on average.The model group rats and the remedy group rats were fed with the water containing (v/v) 6% alcohol for 28 days.After 14 days, the remedy group rats were treated with AOAA (5 mg/kg·d) by intraperitoneal injection once a day for 14 days and the other two group rats were treated with the equal amount of saline by intraperitoneal injection every day.Five days before the end of the experiment, the water maze test was carried out to test the learning and memory ability of rats for 5 days.Subsequently, the content of HS, the activity of ATP enzyme and the expression of 5-HT in hippocampus were measured.@*RESULTS@#Compared with the rats in the control group, the latency and the swimming distance of the 2nd to the 4th day, the content of HS in hippocampus of rats in the model group were all increased, the mitochondrial ATP enzyme activity in hippocampus and the positive expression of 5-HT in hippocampus CA1 and CA3 of rats in the model group were decreased (<0.01).Compared with the rats in the model group, the latency and the swimming distance of the 2nd to the 4th day, the content of HS in hippocampus of the rats in the remedy group were decreased, the mitochondrial ATP enzyme activity in hippocampus and the positive expression of 5-HT in hippocampus CA1 and CA3 of rats in the model group were increased (<0.01).@*CONCLUSIONS@#AOAA could alleviate the symptoms of chronic alcoholism rats, which may be related to the effects of AOAA on the content of HS, the mitochondrial enzyme activity and the expression of 5-HT in hippocampus.

Effects of polydatin on learning and memory and Cdk5 kinase activity in the hippocampus of rats with chronic alcoholism / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To observe the effects of polydatin on learning and memory and cyclin-dependent kinase 5 (Cdk5) kinase activity in the hippocampus of rats with chronic alcoholism.</p><p><b>METHODS</b>Forty rats were randomly divided into 4 groups: control group, chronic alcoholism group, low and high polydatin group. The rat chronic alcoholism model was established by ethanol 3.0 g/(kg · d) (intragastric administration). The abstinence scoring was used to evaluate the rats withdrawal symptoms; cognitive function was measured by Morris water maze experiment; Cdk5 protein expression in the hippocampus was detected by immunofluorescence; Cdk5 kinase activity in the hippocampus was detected by liquid scintillation counting method.</p><p><b>RESULTS</b>The abstinence score, escape latency, Cdk5 kinase activity in chronic alcoholism group rats were significantly higher than those of control group (P < 0.05). The abstinence score, escape latency in high polydatin group rats were significantly lower than those of chronic alcoholism group (P < 0.05); Cdk5 kinase activity in high and low polydatin group rats was significantly lower than that of chronic alcoholism group( P < 0.05); immunofluorescence showed that the Cdk5 positive cells of chronic alcoholism group were significantly increased compared with control group (P < 0.05), and the Cdk5 positive cells of polydatin groups were significantly decreased compared with chronic alcoholism group ( P < 0.05).</p><p><b>CONCLUSION</b>Polydatin-reduced the chronic alcoholism damage may interrelate with regulation of Cdk5 kinase activity.</p>

Molecular phylogenetic evidence for paraphyly of Ceratovacuna and Pseudoregma (Hemiptera, Hormaphidinae) reveals late Tertiary radiation.

Ceratovacuna and Pseudoregma are important groups in Cerataphidini (Hemiptera, Hormaphidinae) that not only produce soldier aphids in galls on the primary hosts but also produce horned soldiers on the herbaceous secondary hosts. However, due to sampling bias in previous studies, the phylogenetic relationships of these two genera remain inconclusive. In this study, based on more extensive sampling and examination of both mitochondrial (cytochrome c oxidase subunit I (COI); cytochrome b (Cytb)) and nuclear (elongation factor-1α (EF-1α); long-wavelength opsin (LWO)) genes, we reconstructed the phylogenetic relationships of Ceratovacuna and Pseudoregma. Phylogenetic analyses, along with morphological evidence, suggested that these two genera belong to the paraphyletic groups with species clustered into three main groups. The monophyly of Ceratovacuna and Pseudoregma as a whole was generally supported by all analyses. Monophyly of Pseudoregma was also supported. The estimated divergence times demonstrated that diversification of Ceratovacuna and Pseudoregma occurred approximately at 10 mya. The relatively low resolution for the basal relationships of the three main clades may indicate that these two genera have experienced a rapid radiation along with speciation burst of their secondary hosts during the late Tertiary.

Changes of protein kinase A expressions in central amygdaloid nuclei during the process of chronic morphine-induced conditioned place aversion in rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To explore neurobiological mechanisms of the withdrawal-induced aversion. The changes of protein kinase A were measured in central amygdaloid nucleic (CeA) of conditioned place aversion (CPA) model rats.</p><p><b>METHODS</b>(1) All 72 male SD rats were divided into three groups, model group (MN group), and control group (MS group and SN group). MN group was injected with morphine,6.5 days, 10 mg/kg, intraperitoneally (ip), twice per day, naloxone injection, 0.3 mg/kg, ip, along with conditioned place aversion training, to develop the CPA model. The MS group was administrated equivalent volume of morphine and saline. Also the SN group was injected with equivalent volume of saline and naloxone. (2) During the process of morphine-induced CPA, the expression of protein kinase A was assayed with immunohistochemistry in the CeA.</p><p><b>RESULTS</b>In the MN group, protein kinase A expressions in the CeA occurred adaptive changes at different points of CPA (P < 0.05). Protein kinase A expressions after establishment(Day7,134.43 +/- 4.481, P < 0.05), and after extinction (Day 13, 141.01 +/- 3.360, P < 0.01), and after reinstatement (Day 14,137.18 +/- 40.330, P < 0.05) were also lower than those before the establishment of the CPA (Day 5, 124.48 +/- 6.722). However, PKA expressions were not significantly different both in MS group (P > 0.05)and SN group (P > 0.05).</p><p><b>CONCLUSION</b>(1) Protein kinase A expression, in turn regulating the aversion expression, in the CeA probably is a key pathway contributing to the development of CPA. (2) The neuroadaptation mediated by protein kinase A may be one of the important molecular underpinnings of CPA.</p>

Dopamine D2 receptor and transportor corrected in the medial prefrontal contex of morphine-induced conditioned place preference in Sprague-Dawley rats / 中南大学学报(医学版)

OBJECTIVE@#To investigate the expression of dopamine D2 receptors (D2R) and dopamine transportors (DAT) located in the medial prefrontal contex (mPFC) in high and low conditioned place preference (CPP) rats, and to unveil the possible mechanism leading to different CPP susceptibilities.@*METHODS@#One hundred and sixty male Sprague-Dawley rats were randomly assigned into an experiment group (n = 130) and a control group (n = 30). The experiment group was re-classified into 2 groups according to CPP values:high preference group (HP group) and low preference group (LP group). According to the execution time-points after the last administration, the HP and LP group was classified into a 3-hour group (3 h), a 72-hour group (J3d), and a 14-day group (J14d), respectively. At 3 hours, 72 hours, and 14 days after the final injection, rats were killed and cardio-perfused, and the brains were removed and sliced up coronarily. The mRNA levels of D2R and DAT in mPFC were determined with in situ hybridization.@*RESULTS@#There were no significant differences of pretest scores staying at the non-preference chamber among the groups(P = 0.470). However, the test scores of the CPP time stayed at pretest natural preference in the HP group were significantly higher than those of the LP group(P = 0.000). In 3h, J3d, and J14d groups,the expressions of D2R mRNA in the HP group (125.43 +/- 2.90 approximately 142.92 +/- 3.32) were lower than those of LP group (122.25 +/- 2.20 approximately 136.67 +/-5.39) (P = 0.000). In 3h and J3d,the expressions of DAT mRNA in the HP group (157.00 +/- 3.55 approximately 145.15 +/- 3.69) were significantly lower than those of the LP group (150.69 +/- 3.12 approximately 138.84 +/- 3.99) (P = 0.000). In J14d, there were no differences among 3 groups in mPFC (P = 0.458).@*CONCLUSION@#D2R and DAT may be correlated closely and underlie the different susceptibilities to morphine induced CPP.