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In this episode, we’re joined by Dr. Niels Niethard from the University of Tübingen to explore what sleep looks like at the level of cortical microcircuits — and how excitation and inhibition are dynamically reconfigured across brain states. Niels walks us through how excitatory pyramidal neurons interact with distinct inhibitory interneuron populations, including somatostatin (SST) and parvalbumin (PV) cells. We discuss how these cell-type-specific interactions shift from wakefulness to non-REM sleep and into REM, creating fundamentally different circuit configurations across sleep stages. We discuss how sleep spindles, slow oscillations, and REM sleep each create distinct configurations of dendritic and somatic inhibition. Niels explains how spindle timing relative to slow oscillation peaks influences synaptic plasticity and how these processes support selective memory consolidation. The conversation also touches on his work on synaptic downscaling in cortical and hypothalamic networks, the potential link between AMPA receptor regulation and sleep pressure, and how sleep interacts with feeding-related circuits and metabolic state in mice. This episode offers a detailed, cell-type-specific perspective on how excitation and inhibition are balanced across sleep stages, revealing the microcircuit mechanisms underlying memory, synaptic downscaling, and brain homeostasis. Find out more about Dr. Niethard’s lab and see relevant publications below: Cortical circuit activity underlying sleep slow oscillations and spindles. PNAS, 2018Slow-wave sleep drives sleep-dependent renormalization of synaptic AMPA receptor levels in the hypothalamus. PLOS Biolology, 2024Cell-type specific dynamics of calcium activity in cortical circuits over the course of slow wave sleep and rapid eye movement sleep. Journal of Neuroscience, 2021 Check out our NaPS website to find out more about the podcast, our research and events. This recording is the property of the Sleep Science Podcast and not for resale.

We've gathered the NaPS lab to answer all your fascinating questions on all things sleep! A perfect bitesize episode to get stuck into the marvellous world of sleep.  1. How does sleep deprivation affect mental health? - Answered by Martha Wawrzuta Bunney, B. G. , Bunney, W. E. (2013). Mechanisms of Rapid Antidepressant Effects of Sleep Deprivation Therapy: Clock Genes and Circadian Rhythms. Biological PsychiatryFang, H., Tu, S., Sheng, J., Shao, A. (2018). Depression in sleep disturbance: A review on a bidirectional relationship, mechanisms and treatment. Journal of Cellular and Molecular Medicine2. What is narcolepsy? - Answered by Kyrillos Meshreky Leschziner G., Narcolepsy: a clinical review, Practical Neurology 2014;14:323-3313. Does the full moon affect sleep? - Answered by Al Saqib Majumder Casiraghi, L. et al. (2021). Moonstruck sleep: Synchronization of human sleep with the moon cycle under field conditions. Chaput, J. P. et al. (2016). Are Children Like Werewolves? Full Moon and Its Association with Sleep and Activity Behaviors in an International Sample of Children. Sleep Medicine4. How does a smart watch track sleep? - Answered by Yan Wang 5. What is orthosomnia? - Answered by Sophie Smith  Baron, K.G., et al. (2017) Orthosomnia: Are some patients taking the quantified self too far? J Clin Sleep Med6. What is sleep regression and how long does it last? - Answered by Mo Abdellahi Weinraub, M. et al. (2012). Patterns of developmental change in infants' nighttime sleep awakenings from 6 through 36 months of age. Developmental PsychologyBruni O. et al. (2014) Longitudinal study of sleep behavior in normal infants during the first year of life. J Clin Sleep Med7. Does Magnesium Citrate help you sleep? - Answered by Dulni Peramunugamage Magnesium for sleep, Sleep Foundation, 20258. Does dark chocolate help you sleep? - Answered by Martha Nguyen  Abdoli, E. et al. (2024). A clinical trial of the effects of cocoa rich chocolate on depression and sleep quality in menopausal women. Scientific reports,Garbarino, S., Garbarino, E., & Lanteri, P. (2022). Circadian Rhythm, Mood, and Temporal Patterns of Eating Chocolate: A Scoping Review of Physiology, Findings, and Future Directions. NutrientsMusic by Sergio Prosvirini from Pixabay Check out our NaPS website to find out more about the podcast, our research and events. This recording is the property of the Sleep Science Podcast and not for resale.

In this episode, we welcome neuroscientist Michele Bellesi from the University of Camerino to explore the fascinating world of glial cells and their dynamic role in sleep.  Michele guides us through the four types of glial cells: Astrocytes: Regulators of synaptic function and help form the blood brain barrier (BBB)Oligodendrocytes: Crucial for myelination and fast signal transmissionMicroglia: The brain's immune sentinels, important for responding to infection and injury as well as shaping the synaptic landscapeEpendymal Cells: Involved in cerebrospinal fluid (CSF) production and CFS movement around the brainWe dive into how each of these cells types behaves differently across wake, sleep and sleep deprivation and the impacts on each cell types function. Find out more about Michele's work here and see relevant papers below. The role of sleep and wakefulness in myelin plasticity, 2019, GliaSleep loss promotes astrocytic phagocytosis and microglial activation in mouse cerebral cortex, 2017, Journal of Neuroscience Effects of sleep and wake on astrocytes: clues from molecular and ultrastructural studies, 2015, BMC Biology Check out our NaPS website to find out more about the podcast, our research and events. This recording is the property of the Sleep Science Podcast and not for resale.

Can sleep help us unlearn biases and make our memories more positive? Implicit biases are unconscious stereotypes that influence our judgments and decisions - like assuming a particular gender for a specific job role. But what if we could change these biases? In this episode, we explore how manipulations of sleep might help reshape our implicit attitudes. We speak with Professor Xiaoqing Hu, a leading researcher in the use of Targeted Memory Reactivation (TMR) during sleep to alter implicit bias and make memories more positive. Xiaoqing shares his journey of applying Implicit Association Tasks (IATs) to sleep research, and how conflict biases, congruent vs. incongruent data, and task design play a role in measuring and modifying bias. We also dive into the nitty gritty of memory consolidation in sleep — examining how REM and NREM stages contribute to emotional memory consolidation, and how recency vs. saliency affects which memories get updated. Prof. Hu discusses his groundbreaking study demonstrating the ability to update unwanted emotional memories during sleep, and we explore the potential for applying this research to clinical populations. We also consider how individual schemas might influence the effectiveness of TMR across different people. If you would like to find out more about Prof. Hu's work, please see the lab website here. You can find relevant papers below: Unlearning implicit social biases during sleep, 2015Updating memories of unwanted emotions during human sleep, 2022Targeted memory reactivation during sleep influences social bias as a  function of slow-oscillation phase and delta power, 2023Reactivating cue approached positive personality traits during sleep promotes positive self-referential processing, 2024Aversive memories can be weakened during human sleep via the reactivation of positive interfering memories. 2024Disarming emotional memories using Targeted Memory Reactivation during Rapid Eye Movement sleep, 2024Targeted memory reactivation in REM but not SWS selectively reduces arousal responses, 2021 Glossary IAT - Implicit Association Task  - a test used to measure the strength of automatic associations between our concepts that we may not be consciously aware of.  TMR - Targeted Memory Reactivation - A technique used to modify memory processing, through the use of presenting cues (audio or smell) that were associated with learning, whilst a person sleeps. These cues can modify select memories and in recent research is being used in emotional memory.  __________________________________ Host Professor Penny Lewis Produced by Sophie Smith Check out our NaPS website to find out more about the podcast, our research and events. This recording is the property of the Sleep Science Podcast and not for resale.

We're joined by Hongi Ngo, who developed a revolutionary technique for manipulating sleep oscillations during his PhD.  Closed-loop Auditory Stimulation (CLAS), which uses bursts of pink noise which are carefully timed to a particular phase of an existing brain oscillation to either boost or dampen the target oscillation.  It has been used to selectively strengthen or weaken memories, improve the immune response, reduce epileptic seizures, and even potentially to slow down age related cognitive decline. Hongi tells us how he got got the idea for CLAS, explains how it works, and tells us about some of his existing studies.  He talks about combining CLAS with Targeted Memory Reactivation (TMR) and discusses the ideas for future of brain modulation methods with techniques such as transcranial magnetic stimulation (TMS).  Some of the key papers discussed are: Auditory closed-loop stimulation of the sleep slow oscillation enhances memory (2013) Auditory closed-loop stimulation of EEG slow oscillations strengthens sleep and signs of its immune-supportive function (2017) Thalamic spindles promote memory formation during sleep thrugh triple phase-locking of cortical, thalamic and hippocampal rhythms (2017) Examining the optimal timing for closed-loop auditory stimulation of slow-wave sleep in young and older adults (2019) Auditory stimulation during sleep suppresses spike activity in benign epilepsy with centrotemporal spikes (2021) Shaping overnight consolidation via slow-oscillation closed-loop targeted memory reactivation (2022) Check out our NaPS website to find out more about the podcast, our research and events. This recording is the property of the Sleep Science Podcast and not for resale.

How are memories represented in the brain and how can we model this? Professor Anna Schapiro from University of Pennsylvania as we discuss her work on computational modelling of sleep and memory. In this episode, we discuss several kinds of Neural Network models as well as diving into the history of Jay McClleland's Complementary Learning Systems theory and Anna's recent work on combining neural network modeling with EEG.  Find out more about Anna Schapiro and her research group here. Links to articles discussed in this episode: Why there are Complementary Learning Systems in the hippocampus and neocortexMethods for reducing interference in the Complementary Learning Systems modelSelf-recovery of memory via generative replayA unifying account of reply as context-driven memory reactivationHost: Penny Lewis Editor: Sophie Smith Check out our NaPS website to find out more about the podcast, our research and events. This recording is the property of the Sleep Science Podcast and not for resale.

How does our sleep change as we age and what could this mean for memory and cognition? In this episode, we discuss with Professor Rebecca Spencer her research  exploring how our sleep patterns evolve over the course of our lives.  We explore the phenomenon of infantile amnesia - why we can't remember our earliest childhood experiences - and unpack the theories behind it. We discuss how hippocampal development changes as we age and how this links to memory consolidation and sleep. We also dive into Rebecca's work on emotional processing in children and how naps and sleeping are able to aid in emotional regulation.  Rebecca runs the Somneuro Lab at the University of Massachusetts Amherst. Find out more about Rebecca and her research group here. Links to studies in the episode: Napping reduces emotional attention bias during early childhoodUnhealthy diet is associated with poor sleep in preschool-aged childrenTelevision use and its effects on sleep in early childhood Host: Professor Penny Lewis Editor: Sophie Smith Check out our NaPS website to find out more about the podcast, our research and events. This recording is the property of the Sleep Science Podcast and not for resale.

In this deep dive episode, we look at how sleep onset can help creativity.  With our amazing guest speakers, Professor Bob Stickgold, Dr Adam Horowitz, Professor Delphine Oudiette and Dr Celia Lacaux, we take a look at their work on creativity, dreams and N1 sleep.  Together, we discuss different definitions of creativity, what defines N1 and what it is about N1 that makes it prime time for creative processing.  Find out more about our guest speakers: Professor Bob StickgoldDr Adam HorowitzProfessor Delphine OudietteDr Celia LacauxPapers from the episode: Sleep onset is a creative sweetspot Replaying the Game: Hypnagogic Images in Normals and AmnesicsDormio: A targeted dream incubation device Host: Professor Penny Lewis Editor: Sophie Smith  Check out our NaPS website to find out more about the podcast, our research and events. This recording is the property of the Sleep Science Podcast and not for resale.

Sleepwalking, sleep talking, night terrors - how do they occur and why do some people have them more than others? Join us as we discuss with Professor Francesca Siclari her work looking at non-REM parasomnias and the link to dreaming. We discuss the various forms that non-REM parasomnias can take, how they differ between adults and children and what the potential consequences of them can be.  Find out more about Francesca and her research group here. Here are links to some of the studies: Conscious experiences during non-REM parasomniasShared EEG correlates between non-REM parasomnia experiences and dreamsConsciousness in non-REM-parasomnia episodes  Host: Professor Penny Lewis Producer & Editor: Sophie Smith  Check out our NaPS website to find out more about the podcast, our research and events. This recording is the property of the Sleep Science Podcast and not for resale.

To kickstart season 3 of the Sleep Science Podcast, we have the lab behind the podcast, NaPS Lab, to answer some great sleep-related questions from our listeners. Thanks to everyone who sent in questions! 1. What is lucid dreaming? - Answered by Mo Abdellahi Lucid dreaming - Stephen LaBerge, 2009Induction of self awareness in dreams through frontal low current stimulation of gamma activity Real-time dialogue between experimenters and dreamers during REM sleep 2. Do dreams do anything for us? - Answered by Kyrillos Meshreky The brain as a dream state generator: an activation-synthesis hypothesis of the dream process Converging theories on dreamingPredictive coding under the free-energy principle3. What types of memory does sleep help you consolidate? - Answered by Yan Wang The whats and whens of sleep-dependent memory consolidationThe role of Sleep in declarative memory consolidation - direct evidence by intracranial EEGSleep, Memory, and Plasticity4. How does sleep change as you age? - Answered by Megan Wadon Sleep across the lifespanThe architecture of early childhood sleep Normal sleep in children and adolescence5. Why do adolescences sleep longer? - Answered by Martha Nguyen National Sleep Foundation’s sleep time duration recommendationsSleep in Children and Adolescents with Behavioral and Emotional DisordersSleep quality and adolescent default mode network connectivity 6. Does the menstrual cycle affect our sleep? - Answered by Marta Wawrzuta Changes in sleeping energy metabolism and thermoregulation during menstrual cycle7. How do the seasons affect our sleep? - Answered by Sophie Smith  Circadian entrainment to the Natural Light-Dark cycle across seasons and the weekendSeasonality of human sleep: polysomnographic data of a neuropsychiatric sleep clinicCheck out our NaPS website to find out more about the podcast, our research and events. This recording is the property of the Sleep Science Podcast and not for resale.

For our end of season special, we have the rest of the NaPS lab in to answer a number of exciting sleep-related questions from our listeners. These touch on a range of different subjects from sleeps involvement in weight gain to alcohol's effect on sleep. Thanks to those who sent in questions! List of Questions: 1.     What is it in general anaesthetic that completely prevents a patient from waking up mid-surgery? Is this a similar state to being in a deep sleep or is this different entirely?  3:43 2.    Can having daytime naps improve your memory?  5:24 3.    Can a good sleep schedule help you lose weight?  6:40 4.    Why do people tend to have a deeper sleep after drinking alcohol?   8:26 5.   Can a lack of sleep really impact the way your brain works long term?  11:24 6.   Why do children with ASD struggle to fall asleep and maintain sleep?  12:54 7.   How does loud snoring or sleep talking wake up other people but not manage to wake up the person themselves?  16:13 8.  How does drinking lots of caffeinated drinks affect our sleep wake cycle?  19:17 9.   How does hibernation differ from a normal sleep in some animals?   21:05 10.  When people say the term “just sleep on it” after a row or an emotional experience, is there any truth in this? Does sleep help you process emotions?   23:24 11.  How much is sleep deprivation related to our immunity?  25:05 This episode was produced by Bella Mills-Smith  This recording is property of the sleep science podcast and not for resale Check out our NaPS website to find out more about the podcast, our research and events. This recording is the property of the Sleep Science Podcast and not for resale.

In this episode, we talk with Professor Chiara Cirelli from the department of Psychiatry at the University of Wisconsin. We begin by hearing about how she first got interested in sleep research, and particularly about her time as a medical student at the University of Pisa where she worked on the noradrenergic system using cat models. We then look at the importance of using cross-species models in sleep research with flies, mice, rats and humans. We also discuss the different ways of using these animal models and the different advantages they offer for sleep research. We then move on to Chiara's Synaptic Homeostasis Hypothesis. This hypothesis has been supported by data from a wide range of species, and suggests that an important function of sleep is to downscale synapses. During the day, brain connections (or synapses) relating to information we have learned get strengthened.  This can result in a kind of neural saturation, whereby there is no space for more synapses. The Synaptic Homeostasis Hypothesis proposes that these synapses are downscaled during sleep, bringing about a form of homeostasis that allows us to repeatedly strengthen synapses during wake and downscale during sleep. We also take a look at different ways of measuring synaptic growth across species such as molecular studies, structural or electrophysiological studies and the current difficulties in following synapses over long periods of time. Finally, we look at Chiara's most recent finding which shows synapses associated with new learning are protected from downscaling during sleep.  Instead, her latest data show that it is the background noise that is reduced during sleep, allowing for an increase in signal to noise ratio. We hope you enjoy the episode and please find more information below.  Here are links to some of the studies mentioned in the podcast: Synaptic Homeostasis Hypothesis Synaptic Homeostasis Hypothesis in Memory Consolidation Downscaling If you would like to find more information of Chiara's work, you can find a link to her research page here. Glossary of terms Synaptic Homeostasis  - Renormalistion of overall synaptic strength to restore cellular homeostasis, preventing saturation and allowing further memory formation following a day of learning   ATP 'cost' - ATP is our source of energy for everything that we do. An ATP 'cost' would refer to how much cellular energy something would use. Declarative learning - Learning about knowledge which we can talk about e.g dates, facts, events.   Drosophila - a genus of flies, commonly referred to as fruit flies, which are used regularly in scientific research. Smart down selection - A process of selectively protecting synapses which need to be kept during downscaling. Phosphorylation - Process of adding a phosphoryl group to a molecule. Phosphorylation can help regulate cell signals or protein development often acting as a way of 'labeling' cells. Noradrenergic System - A neurotransmitter system within our nervous system that is often associated with alertness or arousal. - Episode produced by Sophie Smith  This recording is property of the sleep science podcast and not for resale Check out our NaPS website to find out more about the podcast, our research and events. This recording is the property of the Sleep Science Podcast and not for resale.

In this episode, we interviewed Professor Reto Huber, who leads a research group at the University Children’s Hospital, Zurich. Reto’s interests encompass sleep disorders, development, synaptic plasticity and regeneration.  In this episode we discuss local sleep, a process whereby different parts of the brain express different depths of sleep or wake at different times. We consider the relationship of local sleep to phenomena such as sleep walking and sleep talking, and Reto explains a series of experiments exploring how local sleep relates to learning.  We then consider the use of drosophila as a model to study sleep and the sleep homeostasis hypothesis before switching topic to discuss the developing brain and sleep. Reto explains some important experiments linking sleep to plasticity. We discuss the differences in slow wave activity throughout development, and how the activity corresponds to experience dependent plasticity. We then consider a potential link to childhood conditions such as ADHD.  Finally, Reto explains closed loop auditory stimulation and some recent findings relating to local sleep and learning. We end the episode by exploring the potential use of the technique in clinical settings. If you would like to read more on Reto's work, you can find a link to his publications here. Glossary: Local Sleep - A phenomenon in which different parts of the brain experience different depths of sleep or wake at different times. Sleep Homeostasis- The optimal balancing of sleep and wake driven by sleep pressure and our circadian rhythms Synaptic Homeostasis- Renormalising of overall synaptic strength to restore cellular homeostasis, prevent saturation and allow further memory formation following a day of learning  ADHD- Attention Deficit Hyperactivity Disorder Closed Loop Auditory Stimulation- A method designed to enhance slow wave activity during sleep through auditory stimuli  -  Episode produced by Vanessa Hyde & Sophie Smith This recording is property of the sleep science podcast and not for resale Check out our NaPS website to find out more about the podcast, our research and events. This recording is the property of the Sleep Science Podcast and not for resale.

In this episode we talk to  Professor Manuel Schabus  and Professor Kerstin Hoedlmoser from the Centre for Cognitive Neuroscience at the University of Salzburg.  In this episode, we discuss their work on the development of sleep-in babies, first discussing what baby sleep is like and how it differs from older children and adults in regard to activity and sleep stages and specifically sleep spindles and why we think this is. We also look at the difficulties of recording sleep in babies and what other methods are used to analyse and assess baby sleep.  We then look in depth at the development on sleep spindles in babies and go on to discuss the difference between fast and slow spindles and their hypothesised importance in connection with memory consolidation and learning.  We also discuss the importance of coupling activity and synchrony in the brain, specifically sleep spindles and slow oscillations and how these synchronise as we grow and develop and why this synchrony is important for memory and cognitive function.   If you'd like to find out more about Manuel's work you can find a link to his research page here and a link to Kerstin's research page here. Here are links to some of the studies mentioned in the podcast:         o Fast and slow spindles and their connection to cognitive and memory function         o  Coupling of slow oscillations and sleep spindles and motor learning         o  Coupling of slow oscillations and sleep spindles and memory Glossary of terms Sleep Spindle  - These are a burst of neural activity which usually occur during stage 2 non-REM sleep. (Synaptic) Pruning  - The natural removal of extra synaptic connections between neurons which occurs between childhood and adulthood. Declarative learning - A type of learning about knowledge which we can talk about e.g dates, facts, events. Episodic memory and semantic memory are types of declarative learning. Alpha Activity - A pattern of electric actvity in the brain, alpha activity predominately occurs during rest with a frequency between 9-11Hz.    -   Episode produced by Sophie Smith & Bianca Strete This recording is property of the sleep science podcast and not for resale  Check out our NaPS website to find out more about the podcast, our research and events. This recording is the property of the Sleep Science Podcast and not for resale.

In this episode, we talk to Professor Wenbiao Gan from the Neuroscience and Physiology and Skirball Institute at New York University School of Medicine. Professor Gan tells us about how he started to become interested in studying sleep and its impact on learning and memory. He talks about intriguing and hands-on ways to assess the formation and elimination of dendritic spines in  the mouse cortex, and how different experimental tasks like running backwards on a treadmill influence spine formation with or without sleep. Some counterintuitive results are presented and Professor Gan also shares his perspective on the synaptic homeostasis hypothesis. In the end, Professor Gan gives some thoughts about the future of sleep research and suggests new methods of improvement in the area. If you would like to find out more, here is a link to Professor Gan's full list of publications: Links to  the studies mentioned in the podcast: REM sleep promotes experience-dependent dendritic spine elimination in the mouse cortexFear extinction reverses dendritic spine formation induced by fear conditioning in the mouse auditory cortexREM sleep selectively prunes and maintains new synapses in development and learningExperience‐dependent plasticity of dendritic spines of layer 2/3 pyramidal neurons in the mouse cortexTwo-photon microscopy as a tool to investigate the therapeutic time window of methylprednisolone in a mouse spinal cord injury modelSleep contributes to dendritic spine formation and elimination in the developing mouse somatosensory cortexGlossary of terms  (synaptic) pruning = a natural phase in the development of the nervous system during which connections between neurons that are no longer needed die off dendrites = tree-like extensions of the neuron dendritic spines = extensions of a dendrite that help receive information from other neuronssynaptic homeostasis = the idea that neural synapses cannot keep strengthening forever.  Instead, they must also downscale at some point in order to make space for further strengthening.  Such downscaling can be done in a relative manner that preserves information coded by the synapses in question.  Episode produced by Bianca Strete and Sophie Smith  Check out our NaPS website to find out more about the podcast, our research and events. This recording is the property of the Sleep Science Podcast and not for resale.