Journal of Circadian Rhythms最新文献

{"title":"Opening the Debate: How to Fulfill the Need for Physicians' Training in Circadian-Related Topics in a Full Medical School Curriculum.","authors":"Julia M Selfridge,&nbsp;Kurtis Moyer,&nbsp;Daniel G S Capelluto,&nbsp;Carla V Finkielstein","doi":"10.5334/jcr.ah","DOIUrl":"https://doi.org/10.5334/jcr.ah","url":null,"abstract":"<p><strong>Background: </strong>Circadian rhythms are daily changes in our physiology and behavior that are manifested as patterns of brain wave activity, periodic hormone production, recurring cell regeneration, and other oscillatory biological activities. Their importance to human health is becoming apparent; they are deranged by shift work and jet-lag and in disparate conditions such as insomnia, sleep syndromes, coronary heart attacks, and depression, and are endogenous factors that contribute to cancer development and progression.</p><p><strong>Discussion: </strong>As evidence of the circadian connection to human health has grown, so has the number of Americans experiencing disruption of circadian rhythms due to the demands of an industrialized society. Today, there is a growing work force that experiences night shift work and time-zone shifts shaping the demands on physicians to best meet the needs of patients exposed to chronic circadian disruptions. The diverse range of illness associated with altered rhythms suggests that physicians in various fields will see its impact in their patients. However, medical education, with an already full curriculum, struggles to address this issue.</p><p><strong>Summary: </strong>Here, we emphasize the need for incorporating the topic of circadian rhythms in the medical curriculum and propose strategies to accomplish this goal.</p>","PeriodicalId":15461,"journal":{"name":"Journal of Circadian Rhythms","volume":"13 ","pages":"7"},"PeriodicalIF":0.0,"publicationDate":"2015-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4835682/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34423897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sleep and Food Choice in a Dutch Student Population.","authors":"Cathalijn H C Leenaars,&nbsp;Inge P M Klinkenberg,&nbsp;Audrey Aussems,&nbsp;Nedim Borger,&nbsp;Vivian Faatz,&nbsp;Anneloes Hak,&nbsp;Ellen Houben,&nbsp;Joyce Ramackers,&nbsp;Daphne Snackers,&nbsp;Andries Kalsbeek","doi":"10.5334/jcr.ag","DOIUrl":"https://doi.org/10.5334/jcr.ag","url":null,"abstract":"<p><strong>Background: </strong>The increased risk of obesity among short sleepers is most likely explained by increased energy intake. However, food intake could not only be altered quantitavely but also qualitatively. Therefore, we performed a correlational analysis on self-reported food intake and sleep in 51 students from Maastricht and surroundings.</p><p><strong>Results: </strong>Students that slept longer had a lower caloric intake: ρ = -0.378, p = 0.006, the amount of calories consumed per minute awake remaining relatively stable. However, sleep duration did not correlate with intake of percentage fat, saturated fat, carbohydrates or protein. Average energy intake during the reported breakfasts, lunches, dinners or snacks separately did also not correlate with total sleep time.</p><p><strong>Conclusion: </strong>It seems that shorter sleep correlates with absolute caloric intake, but not with the intake of specific dietary components.</p>","PeriodicalId":15461,"journal":{"name":"Journal of Circadian Rhythms","volume":"13 ","pages":"6"},"PeriodicalIF":0.0,"publicationDate":"2015-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4831296/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34423896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intermittent Food Absence Motivates Reallocation of Locomotion and Feeding in Spotted Munia (Lonchura punctulata).","authors":"Amrita Srivastava,&nbsp;Shalie Malik,&nbsp;Garima Yadav,&nbsp;Sangeeta Rani","doi":"10.5334/jcr.af","DOIUrl":"https://doi.org/10.5334/jcr.af","url":null,"abstract":"<p><strong>Background: </strong>Daily feeding and locomotion are interrelated behaviours. The time spent in feeding and rate of food intake depends on food availability. In low food condition, the birds would show intense movement (locomotion) for a longer time throughout the day however during abundant food supply they may chose higher activity and food intake in the morning and evening only. In the present study we hypothesized that in Spotted Munia (Lonchura punctulata), intermittent food availability during day would reallocate their interrelated behaviors, the feeding (food intake) and locomotor activity patterns.</p><p><strong>Methods: </strong>Two groups of birds (N = 6 each) were kept individually in activity cages under 12L:12D. Group 1 (Control; C) had ad libitum food but group 2 (Treatment; T) had food for 6 hours only (2 h presence followed by 2 h absence; 2P:2A) during 12 hour light period. In the first week, group 2 received food with 'lights on' (TI; ZT 0-2, 4-6 and 8-10; where ZT 0= zeitgeber time 0, time of lights ON). In the following week, the food was given 2 hours after 'lights on' (TII; ZT 2-4, 6-8, 10-12). The food intake and locomotor activity under each condition were observed.</p><p><strong>Results: </strong>The results showed that locomotor activity was induced during food deprivation and suppressed during food availability. Also the food deprivation led to increased food intake.</p><p><strong>Conclusion: </strong>Our results suggest that intermittent food availability/deprivation reallocates the locomotor activity and food intake in Spotted Munia.</p>","PeriodicalId":15461,"journal":{"name":"Journal of Circadian Rhythms","volume":"13 ","pages":"5"},"PeriodicalIF":0.0,"publicationDate":"2015-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4831298/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34423895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diurnal Preference Predicts Phase Differences in Expression of Human Peripheral Circadian Clock Genes.","authors":"Andrew Ferrante,&nbsp;David Gellerman,&nbsp;Ahmet Ay,&nbsp;Kerri Pruitt Woods,&nbsp;Allan Michael Filipowicz,&nbsp;Kriti Jain,&nbsp;Neil Bearden,&nbsp;Krista Kenyon Ingram","doi":"10.5334/jcr.ae","DOIUrl":"https://doi.org/10.5334/jcr.ae","url":null,"abstract":"<p><strong>Background: </strong>Circadian rhythms play an integral role in human behavior, physiology and health. Individual differences in daily rhythms (chronotypes) can affect individual sleep-wake cycles, activity patterns and behavioral choices. Diurnal preference, the tendency towards morningness or eveningness among individuals, has been associated with interpersonal variation in circadian clock-related output measures, including body temperature, melatonin levels and clock gene mRNA in blood, oral mucosa, and dermal fibroblast cell cultures.</p><p><strong>Methods: </strong>Here we report gene expression data from two principal clock genes sampled from hair follicle cells, a peripheral circadian clock. Hair follicle cells from fourteen individuals of extreme morning or evening chronotype were sampled at three time points. RNA was extracted and quantitative PCR assays were used to measure mRNA expression patterns of two clock genes, Per3 and Nr1d2.</p><p><strong>Results: </strong>We found significant differences in clock gene expression over time between chronotype groups, independent of gender or age of participants. Extreme evening chronotypes have a delay in phase of circadian clock gene oscillation relative to extreme morning types. Variation in the molecular clockwork of chronotype groups represents nearly three-hour phase differences (Per3: 2.61 hours; Nr1d2: 3.08 hours, both: 2.86) in circadian oscillations of these clock genes.</p><p><strong>Conclusions: </strong>The measurement of gene expression from hair follicles at three time points allows for a direct, efficient method of estimating phase shifts of a peripheral circadian clock in real-life conditions. The robust phase differences in temporal expression of clock genes associated with diurnal preferences provide the framework for further studies of the molecular mechanisms and gene-by-environment interactions underlying chronotype-specific behavioral phenomena, including social jetlag.</p>","PeriodicalId":15461,"journal":{"name":"Journal of Circadian Rhythms","volume":"13 ","pages":"4"},"PeriodicalIF":0.0,"publicationDate":"2015-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4832819/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34423894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Functional Data Analysis Approach for Circadian Patterns of Activity of Teenage Girls.","authors":"Ruzong Fan,&nbsp;Victoria Chen,&nbsp;Yunlong Xie,&nbsp;Lanlan Yin,&nbsp;Sungduk Kim,&nbsp;Paul S Albert,&nbsp;Bruce Simons-Morton","doi":"10.5334/jcr.ac","DOIUrl":"https://doi.org/10.5334/jcr.ac","url":null,"abstract":"<p><strong>Background: </strong>Longitudinal or time-dependent activity data are useful to characterize the circadian activity patterns and to identify physical activity differences among multiple samples. Statistical methods designed to analyze multiple activity sample data are desired, and related software is needed to perform data analysis.</p><p><strong>Methods: </strong>This paper introduces a functional data analysis (fda) approach to perform a functional analysis of variance (fANOVA) for longitudinal circadian activity count data and to investigate the association of covariates such as weight or body mass index (BMI) on physical activity. For multiple age group adolescent school girls, the fANOVA approach is developed to study and to characterize activity patterns. The fANOVA is applied to analyze the physical activity data of three grade adolescent girls (i.e., grades 10, 11, and 12) from the NEXT Generation Health Study 2009-2013. To test if there are activity differences among girls of the three grades, a functional version of the univariate F-statistic is used to analyze the data. To investigate if there is a longitudinal (or time-dependent activity count) difference between two samples, functional t-tests are utilized to test: (1) activity differences between grade pairs; (2) activity differences between low-BMI girls and high-BMI girls of the NEXT study.</p><p><strong>Results: </strong>Statistically significant differences existed among the physical activity patterns for adolescent school girls in different grades. Girls in grade 10 tended to be less active than girls in grades 11 & 12 between 5:30 and 9:30. Significant differences in physical activity were detected between low-BMI and high-BMI groups from 8:00 to 11:30 for grade 10 girls, and low-BMI group girls in grade 10 tended to be more active.</p><p><strong>Conclusions: </strong>The fda approach is useful in characterizing time-dependent patterns of actigraphy data. For two-sample data defined by weight or BMI values, fda can identify differences between the two time-dependent samples of activity data. Similarly, fda can identify differences among multiple physical activity time-dependent datasets. These analyses can be performed readily using the fda R program.</p>","PeriodicalId":15461,"journal":{"name":"Journal of Circadian Rhythms","volume":"13 ","pages":"3"},"PeriodicalIF":0.0,"publicationDate":"2015-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4831276/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34423893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rhythmic Trafficking of TRPV2 in the Suprachiasmatic Nucleus is Regulated by Prokineticin 2 Signaling.","authors":"Katherine J Burton,&nbsp;Xiaohan Li,&nbsp;Jia-Da Li,&nbsp;Wang-Ping Hu,&nbsp;Qun-Yong Zhou","doi":"10.5334/jcr.ad","DOIUrl":"https://doi.org/10.5334/jcr.ad","url":null,"abstract":"<p><p>The mammalian circadian clock is composed of single-cell oscillators. Neurochemical and electrical signaling among these oscillators is important for the normal expression of circadian rhythms. Prokineticin 2 (PK2), encoding a cysteine-rich secreted protein, has been shown to be a critical signaling molecule for the regulation of circadian rhythms. PK2 expression in the suprachiasmatic nucleus (SCN) is highly rhythmic, peaking during the day and being essentially absent during the night. Mice with disrupted PK2 gene or its receptor PKR2 display greatly reduced rhythmicity of broad circadian parameters such as locomotor activity, body temperature and sleep/wake patterns. PK2 has been shown to increase the firing rate of SCN neurons, with unknown molecular mechanisms. Here we report that TRPV2, an ion channel belonging to the family of TRP, is co-expressed with PKR2 in the SCN neurons. Further, TRPV2 protein, but not TRPV2 mRNA, was shown to oscillate in the SCN in a PK2-dependent manner. Functional studies revealed that TRPV2 enhanced signaling of PKR2 in calcium mobilization or ion current conductance, likely via the increased trafficking of TRPV2 to the cell surface. Taken together, these results indicate that TRPV2 is likely part of the downstream signaling of PK2 in the regulation of the circadian rhythms. </p>","PeriodicalId":15461,"journal":{"name":"Journal of Circadian Rhythms","volume":"13 ","pages":"2"},"PeriodicalIF":0.0,"publicationDate":"2015-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4832818/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34423892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Circadian Pattern of Melatonin MT1 and MT2 Receptor Localization in the Rat Suprachiasmatic Nucleus.","authors":"Nermien E Waly,&nbsp;Richard Hallworth","doi":"10.5334/jcr.ab","DOIUrl":"https://doi.org/10.5334/jcr.ab","url":null,"abstract":"<p><p>The suprachiasmatic nucleus (SCN) is the master circadian pacemaker. The pineal hormone melatonin is involved in the regulation of circadian phase. As a part of the circadian system, its synthesis and secretion is under SCN control. On the other hand, melatonin feeds back on the SCN to regulate its function. Melatonin has two specific windows of time at which it regulates SCN function, namely dusk and dawn. It has been suggested that melatonin exerts its effect on the SCN during that specific window of time via one or both of its specific receptors, MT1 or MT2. The hypothesis that the density of these receptors varies across the circadian cycle was tested. Using immunohistochemistry with receptor-specific antibodies, the localization and distribution of melatonin receptors MT1 and MT2 was studied in the SCN at different Zeitgeber times (ZT): ZT 11-13 (dusk), 23-01 (dawn), 5-7 (mid-day), and 17-19 (midnight). Our results show that MT1 receptor density significantly increased at dusk relative to dawn and midnight (p<0.01 and p<0.001 respectively). Although MT1 receptors were widespread in the SCN and parts of the optic chiasm at dusk, they were restricted to the SCN during the mid-day period. MT2 receptors were not detected in the SCN. Thus, we find that melatonin receptor MT1 density and distribution varies with circadian time. This creates a time window during which melatonin can affect the operation of the SCN. We also find that melatonin regulates SCN function via MT1 receptors with a minimal role for MT2. </p>","PeriodicalId":15461,"journal":{"name":"Journal of Circadian Rhythms","volume":"13 ","pages":"1"},"PeriodicalIF":0.0,"publicationDate":"2015-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4831275/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34423891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prevalence of Insomnia and Sleep Patterns among Liver Cirrhosis Patients","authors":"H. Al-Jahdali, A. Al Enezi, Ahmed E. Anwar, A. Al-Harbi, S. Baharoon, A. Aljumah, A. Shimemeri, K. Abdullah","doi":"10.5334/jcr.aa","DOIUrl":"https://doi.org/10.5334/jcr.aa","url":null,"abstract":"Background: Few studies are available regarding the prevalence of sleep disturbance in cirrhotic patients without overt hepatic encephalopathy. This study aimed to assess the prevalence of insomnia in stable liver cirrhosis patients who are attending the outpatient clinics at King Abdulaziz Medical City, Riyadh (KAMC-KFNGH). Methods: A cross-sectional study enrolled 200 stable patients with confirmed liver cirrhosis. We used the ICSD-2 definition to assess the prevalence of insomnia. We also collected information about sleep patterns, demographic data, the underlying cause of liver cirrhosis and the severity of liver cirrhosis using Child-Pugh scores (CTP). Results: The mean age was 58.9 (SD ± 12.2) years. Hepatitis C was the most common (60.2%) cause of liver cirrhosis among respondents. The prevalence of insomnia was 42% (84/200). Univarite analysis shows association between coffee intake and the presence of insomnia (56.9% vs. 35.9%, p-value = 0.006). The prevalence of insomnia was higher in hepatitis C (51.7%) compared to hepatitis B (36.8%) and other hepatitis (15%), p-value = 0.001. There was a significant relationship between severity of liver cirrhosis (CTP-A, CTP-C, CTP-B) and prevalence of insomnia: 55%, 36.1% and 32.1% respectively, p-value = 0.009. Insomniac patients were significantly older than non-insomniac (61.6 ± 12.0 vs. 57.0 ± 12.0 years, p = 0.008). Results from the multivariate stepwise analysis showed coffee intake (OR=2.7), hepatitis C (OR = 7.2), CTP-A (OR = 1.9), excessive daytime sleepiness (OR = 5.3) and short sleep duration (OR = 5.7) were the most strongly associated with the presence of insomnia. Conclusion: Our study showed a high prevalence of insomnia in patients with liver cirrhosis.","PeriodicalId":15461,"journal":{"name":"Journal of Circadian Rhythms","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2014-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70675045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Daily blood feeding rhythms of laboratory-reared North American Culex pipiens.","authors":"Megan L Fritz,&nbsp;Edward D Walker,&nbsp;Aaron J Yunker,&nbsp;Ian Dworkin","doi":"10.1186/1740-3391-12-1","DOIUrl":"https://doi.org/10.1186/1740-3391-12-1","url":null,"abstract":"<p><strong>Background: </strong>Blood feeding by free-living insect vectors of disease is rhythmic and can be used to predict when infectious bites will occur. These daily rhythms can also be targeted by control measures, as in insecticide-treated nets. Culex pipiens form pipiens and C.p. f. molestus are two members of the Culex pipiens assemblage and vectors of West Nile Virus throughout North America. Although Culex species vector human pathogens and parasites, the daily blood feeding rhythms of C.p. f. molestus, to our knowledge, have not been studied. We described and compared the daily blood feeding rhythms of three laboratory-reared populations of Culex pipiens, one of which has confirmed molestus ancestry. We also examined the plasticity of blood feeding time for these three populations.</p><p><strong>Results: </strong>For most (>70%) C.p. f. pipiens and C.p. f. molestus collected from metropolitan Chicago, IL, blood feeding took place during scotophase. Peak blood feeding occurred in mid-scotophase, 3-6 hours after lights off. For C.p. f. pipiens originating from Pennsylvania, most mosquitoes (> 90%) blood fed during late photophase and early scotophase. C.p. f. molestus denied a blood meal during scotophase were less likely to blood feed during early photophase (< 20%) than were C.p. f. pipiens from Chicago (> 50%). C.p. f. pipiens from Pennsylvania were capable of feeding readily at any hour of photo- or scotophase.</p><p><strong>Conclusions: </strong>Daily blood feeding rhythms of C.p. f. molestus are similar to those of C.p. f. pipiens, particularly when populations originate from the same geographic region. However, the timing of blood feeding is more flexible for C.p. f. pipiens populations relative to C.p. f. molestus.</p>","PeriodicalId":15461,"journal":{"name":"Journal of Circadian Rhythms","volume":"12 1","pages":"1"},"PeriodicalIF":0.0,"publicationDate":"2014-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/1740-3391-12-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32052182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Daily cycling of nitric oxide synthase (NOS) in the hippocampus of pigeons (C. livia).","authors":"Aline V Machado-Nils,&nbsp;Larissa Om de Faria,&nbsp;André S Vieira,&nbsp;Simone A Teixeira,&nbsp;Marcelo N Muscará,&nbsp;Elenice Am Ferrari","doi":"10.1186/1740-3391-11-12","DOIUrl":"https://doi.org/10.1186/1740-3391-11-12","url":null,"abstract":"<p><strong>Background: </strong>Nitric oxide synthase (NOS) is essential for the synthesis of nitric oxide (NO), a non-conventional neurotransmitter with an important role in synaptic plasticity underlying processes of hippocampus-dependent memory and in the regulation of biological clocks and circadian rhythms. Many studies have shown that both the NOS cytosolic protein content and its enzymatic activity present a circadian variation in different regions of the rodent brain, including the hippocampus. The present study investigated the daily variation of NOS enzymatic activity and the cytosolic content of nNOS in the hippocampus of pigeons.</p><p><strong>Results: </strong>Adult pigeons kept under a skeleton photoperiod were assigned to six different groups. Homogenates of the hippocampus obtained at six different times-of-day were used for NOS analyses. Both iNOS activity and nNOS cytosolic protein concentrations were highest during the subjective light phase and lowest in the subjective dark phase of the circadian period. ANOVA showed significant time differences for iNOS enzymatic activity (p < 0.05) and for nNOS protein content (p < 0.05) in the hippocampus. A significant daily rhythm for both iNOS and nNOS was confirmed by analysis with the Cosinor method (p < 0.05). The present findings indicate that the enzymatic activity of iNOS and content of nNOS protein in the hippocampus of pigeons exhibit a daily rhythm, with acrophase values occurring during the behavioral activity phase.</p><p><strong>Conclusions: </strong>The data corroborate the reports on circadian variation of NOS in the mammalian hippocampus and can be considered indicative of a dynamic interaction between hippocampus-dependent processes and circadian clock mechanisms.</p>","PeriodicalId":15461,"journal":{"name":"Journal of Circadian Rhythms","volume":" ","pages":"12"},"PeriodicalIF":0.0,"publicationDate":"2013-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/1740-3391-11-12","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40280867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}