Partner im RedaktionsNetzwerk Deutschland

CHRONO:MEDICINE

Dr. Jan-Frieder Harmsen
CHRONO:MEDICINE
Neueste Episode

Verfügbare Folgen

5 von 29
  • E29 - Glucocorticoids with Henriette Uhlenhaut (EBRS 2025 Spotlight 2)
    As the second spotlight for the European Biological Rhythms Society (EBRS) congress (taking place in Lübeck in Northern Germany from the 24th to 28th of August 2025), Prof. Henriette Uhlenhaut (Professor of 'Metabolic Programming' at the Technical University of Munich (TUM) and Director of the Institute for Diabetes and Endocrinology at the Helmholtz Center in Munich) talks about glucocorticoids (such as cortisol), commonly known as the “stress hormones”. We discuss how glucocorticoids regulate gene expression at many different sites within our body and how they play different roles in metabolism, immune responses and inflammation. Wehighlight that glucocorticoids are secreted in a strongly circadian manner and describe which kind of events can acutely increase cortisol levels independent of rhythmic secretion. In contrast to common belief, Henriette explains whyhigh cortisol levels are not always a bad thing, highlighting important links to fasting and caloric restriction. Lastly, Henriette shares her experience attending previous EBRS congresses and why you should consider joining it this year. Chapters:(0:00:38) Introducing the EBRS 2025 spotlights(0:03:39) Henriette Uhlenhaut(0:06:08) Basics of glucocorticoids(0:16:26) Circadian rhythm of glucocorticoids(0:23:21) How to shift the rhythm?(0:28:49) What events evoke a cortisol response? (0:36:45) Stress hormones - a fair description?(0:39:08) Cortisol vs. melatonin(0:42:16) Link to caloric restriction(0:50:25) EBRS experience(0:53:45) EBRS teaser(0:56:30) Advice for early career researchers(1:00:28) Funny anecdote(1:06:35) Outro  Studies that Henriette and I refer to:Studies on the % of genes that are regulated byglucocorticoids (liver, immune cells etc.): https://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.0010016 https://pmc.ncbi.nlm.nih.gov/articles/PMC2792167/ https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2020.572981/full  Glucocorticoids universally regulate clock genes such as Per1 inevery cell type: https://doi.org/10.1093/emboj/20.24.7128https://doi.org/10.1210/en.2012-1486 The more fasted you are, the higher your cortisol levels: https://doi.org/10.3109/10253890.2015.1121984 Light stimulates ACTH secretion = activation of thehypothalamic-pituitary-adrenal axis: https://academic.oup.com/edrv/article/41/3/bnaa002/5736359 Shifting the last meal of the day shifts cortisol secretion: https://pmc.ncbi.nlm.nih.gov/articles/PMC5483233/ Shifting sleep time shifts cortisol secretion: https://pmc.ncbi.nlm.nih.gov/articles/PMC11899833/ If the feeding time of mice is reversed, there are two peaks incorticosterone secretion: one peak driven by the central clock, and one driven by food availability: https://www.embopress.org/doi/full/10.1093/emboj/20.24.7128 Exercise can change cortisol secretion, also locally in tissues: https://link.springer.com/article/10.2165/00007256-200535050-00003#Sec4 https://journals.physiology.org/doi/full/10.1152/japplphysiol.00108.2002 Maternal stress impacts the newborn: https://doi.org/10.1016/j.biopsych.2010.05.028 Caloric restriction boosts the cortisol amplitude: https://www.cell.com/cell-reports/fulltext/S2211-1247(15)01483-7 Symptoms of rheumatoid arthritis, cough and fever show 24-hourrhythms: https://link.springer.com/chapter/10.1007/978-3-642-78734-8_35 https://www.sciencedirect.com/science/article/pii/S0091674995702121#bib27 https://www.tandfonline.com/doi/abs/10.3109/07420528809067786 Beyond 12 to 14 hours of fasting, ketone bodies are built based on liver fat and adipose tissue: https://link.springer.com/article/10.1007/s10545-014-9704-9 https://www.cell.com/trends/endocrinology-metabolism/fulltext/S1043-2760(23)00215-1  Ketogenic diet on rhythmicity in transcriptomes of metabolic organshttps://www.ncbi.nlm.nih.gov/pubmed/28877456 Contact:Henriette’s research group homepage: https://www.mls.ls.tum.de/metabolism/home/
    --------  
    1:07:42
  • E28 - The Central Clock & Melatonin with Michael Hastings (EBRS 2025 Spotlight 1)
    In collaboration with the organizers of the 18th Congress of the European Biological Rhythms Society (EBRS) (taking place in Lübeck in Northern Germany from the 24th to 28th of August 2025), three congress speakers are interviewed to talk about their research. As the first spotlight, Prof. Michael Hastings (MRC Laboratory of Molecular Biology, Cambridge) talks about his research journey from circatidal rhythms in marine organisms to circadian and circaannual rhythms in mammals. Our main focus is on the neurochemistry within the central clock of the suprachiasmatic nucleus (SCN) enabling it to tell time. We discuss the most relevant factors that support the SCN in telling time, and what means the SCN has to synchronize other clocks within our body. With respect to melatonin, we discuss its role in sleep versus informing our body about the current season. We also talk about supplementing melatonin for specific populations. Lastly, Michael shares memories from attending previous EBRS congresses and why you should consider joining it this year.Chapters:(00:00:39) Introducing the EBRS 2025 spotlights(00:03:51) Michael Hastings(00:07:17) Circatidal rhythms(00:14:38) The central clock or SCN(00:24:47) Different zeitgebers(00:35:17) Melatonin(00:46:14) Melatonin as a sleeping aid(00:51:38) EBRS congress experience(00:58:22) Career advice(01:10:02) Funny anecdote(01:13:54) Outro Studies that Michael refers to:Reviews on circatidal rhythmshttps://doi.org/10.1016/j.cub.2008.06.041https://doi.org/10.1016/j.tig.2024.01.006 Prevalence of mutations in clock genes to make the period length shorter or longer than approx. 24 hours, rare familial sleep disordershttps://doi.org/10.1038/s41386-019-0476-7 Mice mutations support that the same enzymes are involved as in the human sleep disordershttps://www.nature.com/articles/s41583-018-0026-z Period genes in the SCN are activated by lighthttps://doi.org/10.1016/S0092-8674(00)80494-8 Caffeine can phase shift the circadian clockhttps://doi.org/10.1126/scitranslmed.aac5125 Manipulation of NPY and serotonin can shift the SCN clock https://doi.org/10.1152/ajpregu.00320.2022 Human cortisol levels increase before awakening in anticipation of wakehttps://doi.org/10.1677/JOE-07-0378 Temperature in the physiological range can act as a zeitgeber to entrain peripheral clockshttps://doi.org/10.1016/S0960-9822(02)01145-4 When interfering with neuropeptide levels within the SCN, you can entrain the SCN with temperature cycleshttps://doi.org/10.1126/science.1195262 High levels of estradiol make the SCN run fasterhttps://doi.org/10.1126/science.557840 Melatonin is a transplacental zeitgeberhttps://pubmed.ncbi.nlm.nih.gov/3780553/https://doi.org/10.1177/074873049701200603 Martha Gillette and others applied melatonin to brain slides containing the SCN, showing that this could shift the SCN clock, the sensitivity of the SCN to this melatonin effect was found to occur during daytime (when melatonin is not released naturally)https://link.springer.com/article/10.1007/s00441-002-0576-1 GWAS papers: variance of melatonin receptor are related to the type 2 diabetes andmetabolic disordershttps://www.nature.com/articles/ng.277https://www.nature.com/articles/s41574-018-0130-1Contacting Michael Hastings:Homepage: https://www2.mrc-lmb.cam.ac.uk/group-leaders/h-to-m/michael-hastings/Email: ⁠[email protected]⁠EBRS homepage:https://ebrs-online.org
    --------  
    1:14:44
  • E27 - Part 2: A good night's sleep with Christian Benedict
    In this second part, Dr. Christian Benedict (Department of Pharmaceutical Biosciences, Research and Pharmacology at Uppsala University, Sweden) explains how our sleep changes with aging and upon different challenges of adult life. We discuss the so-called gold-standard method for measuring sleep (Polysomnography, PSG) and how modern wearable technologies perform compared to PSG. In this context, Christian evaluates the potential value of measuring heart rate variability (HRV) to assess sleep quality. He also emphasizes the health threat through obstructive sleep apnea (OSA) and how to use simple self-monitoring technologies to determine if you may be affected by OSA yourself. Lastly, we acknowledge poor sleep as a general health risk but also discuss limitations and problems that can arise from overstating this. Chapters:(0:00:12) Intro(0:02:20) Aging and sleep(0:11:10) Polysomnography (PSG)(0:22:25) Sleep wearables & HRV(0:27:07) Obstructive sleep apnea(0:33:10) Limitations of wearables(0:36:41) Sleep across chronotypes(0:44:50) Poor sleep as a health risk?(0:55:19) Outro Studies that Christian refers to:Meta-analysis (2004) PSG data over the lifespanhttps://pubmed.ncbi.nlm.nih.gov/15586779/ Paper on app findings of almost a million people asked on “how long do you sleep?”https://pubmed.ncbi.nlm.nih.gov/36509747/ Studies on PSG vs. some commercial wearables ?https://jcsm.aasm.org/doi/10.5664/jcsm.7128 Sleep apnea: Spotlight article with Jesse Cooks and Jonathan Cedernaeshttps://pubmed.ncbi.nlm.nih.gov/33180697/ Lancet Respiratory Medicine review, 425 million people suffer from moderate to severeobstructive sleep apneahttps://pubmed.ncbi.nlm.nih.gov/31300334/ Ad-hoc sleep apnea screening in patients admitted to the hospital, 80% are not aware of ithttps://pubmed.ncbi.nlm.nih.gov/19186102/ Australian study using a measurement pillow to track sleep apneahttps://www.atsjournals.org/doi/full/10.1164/rccm.202107-1761OC Christian’s work (2015) those who have over 40 years regular sleep problems have an increased risk for Alzheimer’shttps://pubmed.ncbi.nlm.nih.gov/25438949/ Studies comparing people with kids and without kids, those with kids live longerhttps://jech.bmj.com/content/71/5/424  How to contact Christian Benedict:Email: [email protected]: https://www.linkedin.com/in/christian-benedict-a25b1615a/
    --------  
    55:54
  • E26 - Part 1: A good night's sleep with Christian Benedict
    Dr. Christian Benedict (Senior Lecturer & Associate Professor at the Department of Pharmaceutical Biosciences, Research and Pharmacology at Uppsala University, Sweden) talks about how to study sleep and its relevance for our overall health. In this first part, Christian introduces us to different definitions of sleep. Together, we try to decipher the concept of sleep quality or in other words how to judge if somebody had a good night’s sleep or not. Christian also summarizes the research around the optimal duration of sleep and discusses the relevanceof spending time in different sleep stages.Chapters:(0:00:12) Intro(0:03:41) Christian Benedict’s career path(0:13:06) What is sleep?(0:24:09) Sleep stages & sleep quality (0:34:06) Sleep quantity/duration(0:42:08) Outro & Teaser to Part 2 Studies that Christian refers to:Aversive tobacco smoke during non-REM sleephttps://pubmed.ncbi.nlm.nih.gov/25392505/Epileptic patients and sleep deprivationhttps://pubmed.ncbi.nlm.nih.gov/29106402/Correlations between time in different sleep stages and daytime alertness are not that good, contradictory evidencehttps://pubmed.ncbi.nlm.nih.gov/10678518/Epworthsleepiness scale and sleep stages are not well correlatedhttps://pubmed.ncbi.nlm.nih.gov/19110886/ People struggling with sleep do not necessarily differ in PSG-derived sleep stage outcomes from normally sleeping peoplehttps://pubmed.ncbi.nlm.nih.gov/29402512/ Peer feedback can impact your retrospective judgement of your last night of sleephttps://pubmed.ncbi.nlm.nih.gov/24417326/https://pubmed.ncbi.nlm.nih.gov/33204201/American Society for Sleep Medicine, 7-9 hours, probably 6 and 10 hours are also finehttps://www.thensf.org/wp-content/uploads/2020/10/NSF-SleepDurationTiming_Background-1200x1312-1.jpg Shorter or longer than these 6-10 hours is mostly associated with poor health outcomeshttps://pubmed.ncbi.nlm.nih.gov/11825133/ Christian’s work on interindividual responses in brain health outcomes to sleep losshttps://pubmed.ncbi.nlm.nih.gov/36088460/ Studies showing that people who think they cope well with sleep loss are actually not doing wellhttps://pubmed.ncbi.nlm.nih.gov/29383809/ How to contact Christian Benedict:Email: [email protected]: https://www.linkedin.com/in/christian-benedict-a25b1615a/
    --------  
    43:33
  • E25 - Part 2: Improving health & sleep through daylight with Christian Cajochen
    In the second part with Prof. Christian Cajochen (Head of the Centre for Chronobiology at the University of Basel in Switzerland), contributing to the Daylight Awareness Week (28th of October - 2nd of November 2024), we continue our discussion around the impact of daylight on our health, with a special focus on sleep. Christian summarizes the negative effects of bright electric light exposure on sleep and other health outcomes. On the other hand, he highlights the importance of daylight and alternatively increased electric light intensities during daytime for sleep. We also discuss how seasonal changes in daylight affect us more than we think. Christian gives insights into a real-world example of how switching to dynamic lighting at the workplace changed people’s wellbeing. And lastly, we discuss if a medical pill could eventually replace the health effects of daylight. More information about the Daylight Awareness Week: ⁠https://daylight.academy/daylight-awareness-week-2024/⁠ Chapters: (0:00:12) Intro & Daylight Awareness Week (0:00:48) Topics of this episode series (0:02:13) Introduction to sleep (0:04:15) Evening electric light & sleep (0:09:42) Daylight & sleep (0:15:47) Seasonal effects of daylight (0:20:33) Can higher light intensities during daytime reduce negative effects of evening light? (0:25:47) How to tackle the lack of daylight as a society? (0:36:00) Take-home message on daylight & health (0:37:39) Christian’s career goals & future research (0:41:15) Funny anecdotes (0:47:18) Outro & Teaser to Part 2 Studies that Christian refers to: Evening administration of melatonin and bright light: Interactions on the EEG during sleep and wakefulness https://doi.org/10.1046/j.1365-2869.1998.00106.x Blue Blocker Glasses as a Countermeasure for Alerting Effects of Evening Light-Emitting Diode Screen Exposure in Male Teenagers https://doi.org/10.1016/j.jadohealth.2014.08.002 Evaluating the Association between Artificial Light-at-Night Exposure and Breast and Prostate Cancer Risk in Spain (MCC-Spain Study) https://doi.org/10.1289/EHP1837 Camping Study: “Circadian Entrainment to the Natural Light-Dark Cycle across Seasons and the Weekend” 10.1016/j.cub.2016.12.041 Effect of daylight LED on visual comfort, melatonin, mood, waking performance and sleep https://doi.org/10.1177/1477153519828419 Positive Effect of Daylight Exposure on Nocturnal Urinary Melatonin Excretion in the Elderly: A Cross-Sectional Analysis of the HEIJO-KYO Study https://doi.org/10.1210/jc.2012-1873 Effect of Bright Light and Melatonin on Cognitive and Noncognitive Function in Elderly Residents of Group Care Facilities: A Randomized Controlled Trial https://doi.org/10.1001/jama.299.22.2642 Preprint article: “Sex and seasonal variations in melatonin suppression, and alerting response to light” https://doi.org/10.1101/2024.10.18.619012 Light therapy in non-seasonal depression: An update meta-analysis https://doi.org/10.1016/j.psychres.2020.113247 Pre-print article: “Afternoon to early evening bright light exposure reduces later melatonin production in adolescents” https://doi.org/10.1101/2024.10.02.616112 Regular Caffeine Intake Delays REM Sleep Promotion and Attenuates Sleep Quality in Healthy Men https://doi.org/10.1177/07487304211013995 Evidence that the Lunar Cycle Influences Human Sleep 10.1016/j.cub.2013.06.029 How to contact Christian Cajochen: Email: [email protected] Twitter: @ollen44 LinkeIn: https://www.linkedin.com/in/christian-cajochen-1435258/
    --------  
    48:28

Weitere Gesundheit und Fitness Podcasts

Über CHRONO:MEDICINE

In the CHRONO:MEDICINE podcast (formerly known as 247Muscle), your host (Dr. Jan-Frieder Harmsen) interviews scientists in the field of chronobiology, circadian rhythm, skeletal muscle physiology, exercise performance and sleep. The podcast aims to provide translational knowledge from research findings for students, researchers and the generally interested public.
Podcast-Website

Höre CHRONO:MEDICINE, Alle meine Eltern – Der Real Talk mit Evelyn Weigert und viele andere Podcasts aus aller Welt mit der radio.at-App

Hol dir die kostenlose radio.at App

  • Sender und Podcasts favorisieren
  • Streamen via Wifi oder Bluetooth
  • Unterstützt Carplay & Android Auto
  • viele weitere App Funktionen
Rechtliches
Social
v7.20.1 | © 2007-2025 radio.de GmbH
Generated: 7/4/2025 - 5:17:06 AM