Science Savvy

In this episode, we explore the science of dying. We examine what happens in the brain after cardiac arrest, why consciousness usually fades within seconds, and the remarkable discoveries of brief bursts of brain activity after your heart has stopped.

We also dive into the mystery of near-death experiences. Why do some survivors describe tunnels of light, out-of-body experiences, or profound feelings of peace? Could these experiences be explained? Or are there still unanswered questions about consciousness itself?

Beyond the brain, we follow the body's final biological journey i.e., how different organs shut down, what dying typically feels like, etc.

If you've ever wondered what science can actually tell us about our final moments, this episode is for you.

Bibliography / References:

Beaussant, Y., et al. (2024). Near-death experiences after cardiac arrest: A scoping review. Resuscitation. https://pubmed.ncbi.nlm.nih.gov/38806961/

Borjigin, J., Lee, U., Liu, T., et al. (2013). Surge of neurophysiological coherence and connectivity in the dying brain. Proceedings of the National Academy of Sciences, 110(35), 14432–14437. https://pubmed.ncbi.nlm.nih.gov/23940340/

Borjigin, J., et al. (2023). Surge of neurophysiological coupling and connectivity of gamma oscillations in the dying human brain. Proceedings of the National Academy of Sciences. https://pubmed.ncbi.nlm.nih.gov/37126719/

Chawla, L. S., et al. (2021). Electrocerebral signature of cardiac death. Journal of Palliative Medicine. https://pubmed.ncbi.nlm.nih.gov/34184175/

Dhamoon, M. S., et al. (2006). Mechanisms of brain injury after global cerebral ischemia. Neurologic Clinics, 24(1), 1–21. https://pubmed.ncbi.nlm.nih.gov/16443127/

Drennan, I. R., et al. (2021). European Resuscitation Council and European Society of Intensive Care Medicine guidelines 2021: Post-resuscitation care. Resuscitation, 161, 220–269. https://pubmed.ncbi.nlm.nih.gov/33765189/

Greyson, B. (2003). Incidence and correlates of near-death experiences in a cardiac care unit. General Hospital Psychiatry, 25(4), 269–276. https://pubmed.ncbi.nlm.nih.gov/12850659/

Greyson, B., Kelly, E. W., & Kelly, E. F. (2025). A neuroscientific model of near-death experiences. Annals of the New York Academy of Sciences. https://pubmed.ncbi.nlm.nih.gov/40159547/

Jansen, K. L. R. (2006). Does the arousal system contribute to near-death experience? Medical Hypotheses, 66(5), 1003–1009. https://pubmed.ncbi.nlm.nih.gov/16606911/

Martial, C., et al. (2019). Neurochemical models of near-death experiences: A large-scale study based on the semantic similarity of written reports. Consciousness and Cognition, 69, 52–69. https://pubmed.ncbi.nlm.nih.gov/30711788/

Martial, C., et al. (2019). Neurochemical models of near-death experiences: A large-scale study based on the semantic similarity of written reports. ResearchGate version. https://www.researchgate.net/publication/330778804_Neurochemical_models_of_near-death_experiences_A_large-scale_study_based_on_the_semantic_similarity_of_written_reports

Mobbs, D., & Watt, C. (2011). There is nothing paranormal about near-death experiences: How neuroscience can explain seeing bright lights, meeting the dead, or being convinced you are one of them. Trends in Cognitive Sciences. (Related review.) https://pubmed.ncbi.nlm.nih.gov/22371425/

Nolan, J. P., et al. (2021). European Resuscitation Council and European Society of Intensive Care Medicine guidelines 2021: Post-resuscitation care. Resuscitation, 161, 220–269. https://pubmed.ncbi.nlm.nih.gov/33765189/

Parnia, S., et al. (2001). Near-death experience in survivors of cardiac arrest: A prospective study in the Netherlands. The Lancet, 358(9298), 2039–2045. https://pubmed.ncbi.nlm.nih.gov/11755611/

Parnia, S., et al. (2014). AWARE—AWAreness during REsuscitation: A prospective study. Resuscitation, 85(12), 1799–1805. https://pubmed.ncbi.nlm.nih.gov/25301715/

Parnia, S., et al. (2023). AWAreness during REsuscitation II: A multi-center study of consciousness and awareness during cardiopulmonary resuscitation. Resuscitation. https://pubmed.ncbi.nlm.nih.gov/37423492/

Savio, L. E. B., et al. (2021). Brain injury after cardiac arrest: Pathophysiology, treatment, and prognosis. Intensive Care Medicine. https://pubmed.ncbi.nlm.nih.gov/34705079/

Sessler, D. I., et al. (2017). Electroencephalographic recordings during withdrawal of life-sustaining therapy until 30 hours after death. Anesthesiology, 127(4), 713–724. https://pubmed.ncbi.nlm.nih.gov/28231862/

Timmermann, C., et al. (2018). DMT models the near-death experience. Frontiers in Psychology, 9, 1424. https://pubmed.ncbi.nlm.nih.gov/30174629/

van Lommel, P., et al. (2001). Near-death experience in survivors of cardiac arrest: A prospective study in the Netherlands. The Lancet, 358(9298), 2039–2045. https://pubmed.ncbi.nlm.nih.gov/11755611/

Vrselja, Z., et al. (2018). Terminal spreading depolarizations causing electrocortical silencing prior to clinical brain death. Brain, 142(5), 1313–1329. https://pubmed.ncbi.nlm.nih.gov/30544340/

Woerner, A. C., et al. (2016). Time to loss of brain function and activity during circulatory arrest. Critical Care Medicine, 44(12), e1119–e1128. https://pubmed.ncbi.nlm.nih.gov/27288615/

Woitzik, J., et al. (2018). Terminal spreading depolarization and electrical silence in death of human cerebral cortex. Annals of Neurology, 83(2), 295–310. https://pubmed.ncbi.nlm.nih.gov/29331091/

Yuryev, M., et al. (2016). The continuum of spreading depolarizations in acute cortical lesion development. Journal of Cerebral Blood Flow & Metabolism. https://pubmed.ncbi.nlm.nih.gov/27328690/

Zylicz, Z., et al. (2019). Biosynthesis and extracellular concentrations of N,N-dimethyltryptamine (DMT) in mammalian brain. Scientific Reports. https://pubmed.ncbi.nlm.nih.gov/31249368/

Barker, S. A. (2018). N,N-dimethyltryptamine and the pineal gland: Separating fact from myth. Journal of Psychopharmacology. https://pubmed.ncbi.nlm.nih.gov/29095071/

Barker, S. A., McIlhenny, E. H., & Strassman, R. (2012). A critical review of reports of endogenous psychedelic N,N-dimethyltryptamine in humans: 1955–2010. Drug Testing and Analysis, 4(7–8), 617–635. https://pubmed.ncbi.nlm.nih.gov/22371425/

In this episode (Part 2 of PMDD vs PMS), I interview Liv Nono, co-founder of Velora Salud, about her PMDD diagnosis journey. She tell us all she has learned so far, from tracking her cyclical symptoms to the challenges of getting proper care early. Of course, we discuss the science behind PMDD, so you can understand exactly what differentiates it from PMS.

We cover treatment options, including pharmacological and non-pharmacological options like the Nettle headband, therapy, and lifestyle changes.

To learn more about Velora's mission to build Spanish-language support and peer communities, go to velorasalud.com

To access Liv's blog: PMDD, Grief, and the Brain: A Nettle™ User’s Story | Samphire Neuroscience

References available upon request.

Why do some women feel bloated, emotional, or irritable before their period, while others feel like they become a completely different person? In this episode of Science Savvy Podcast, Professor Rossella Nappi (gynecologist, endocrinologist, and sexologist) breaks down the crucial difference between premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD), and why PMDD is far more than “just bad PMS.” Together, we explore what is really happening in the brain and body, from altered sensitivity to normal hormonal changes to the roles of serotonin, GABA, stress, trauma, and even the gut-brain axis.

Professor Nappi also explains how PMDD is diagnosed, why symptom tracking is important for those seeking help from a physician, as well as the treatments that can actually help (from natural lifestyle changes to hormonal contraception and intermittent use of antidepressants). Most importantly, this episode is a reminder that severe premenstrual symptoms are real, treatable, and never something women should have to just “put up with.”

This episode is for educational purposes only and is not a substitute for medical advice. If you experience severe mood symptoms, thoughts of self-harm, or symptoms that interfere with daily life, please speak with a qualified healthcare professional or seek urgent support.

As this was an interview, we do not have a "formal" bibliography. However, a list of references is available upon request (just leave a comment)!

In this episode of Science Savvy, I speak with Pablo Otero, who holds a PhD from Imperial College London, about how certain substances can affect the body in social settings.

We discuss how mixing substances can increase the chance of unwanted effects, how the body responds under different conditions, and why avoiding recreational substance use is the lowest-risk choice.

This episode is for educational purposes only. It does not encourage recreational substance use or provide medical advice.

Reading list: Available on request.

Why do some women feel bloated, emotional, or irritable before their period, while others feel like they become a completely different person? In this episode of Science Savvy Podcast, Professor Rossella Nappi (gynecologist, endocrinologist, and sexologist) breaks down the crucial difference between premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD), and why PMDD is far more than “just bad PMS.” Together, we explore what is really happening in the brain and body, from altered sensitivity to normal hormonal changes to the roles of serotonin, GABA, stress, trauma, and even the gut-brain axis.

Professor Nappi also explains how PMDD is diagnosed, why symptom tracking is important for those seeking help from a physician, as well as the treatments that can actually help (from natural lifestyle changes to hormonal contraception and intermittent use of antidepressants). Most importantly, this episode is a reminder that severe premenstrual symptoms are real, treatable, and never something women should have to just “put up with.”

As this was an interview, we do not have a "formal" bibliography. However, here are the papers I read to prepare:

Tiranini L, Nappi RE. Recent advances in understanding/management of premenstrual dysphoric disorder/premenstrual syndrome. Fac Rev. 2022 Apr 28;11:11. doi:10.12703/r/11-11. PMID: 35574174.

Facchinetti F, Borella P, Sances G, Fioroni L, Nappi RE, Genazzani AR. Oral magnesium successfully relieves premenstrual mood changes. Obstet Gynecol. 1991 Aug;78(2):177-181. PMID: 2067759.

Verri A, Nappi RE, Vallero E, Galli C, Sances G, Martignoni E. Premenstrual dysphoric disorder and eating disorders. Cephalalgia. 1997 Dec;17 Suppl 20:25-28. doi:10.1177/0333102497017S2008. PMID: 9496774.

Nappi RE, Petraglia F, Luisi S, Polatti F, Farina C, Genazzani AR. Serum allopregnanolone in women with postpartum "blues". Obstet Gynecol. 2001 Jan;97(1):77-80. doi:10.1016/S0029-7844(00)01112-1. PMID: 11152912.

Studd J, Nappi RE. Reproductive depression. Gynecol Endocrinol. 2012 Mar;28 Suppl 1:42-45. doi:10.3109/09513590.2012.651932. PMID: 22394303.

Lete I, Häusler G, Pintiaux A, Jamin C, Nappi RE, Fiala C, Chabbert-Buffet N, Lobo P. The inconvenience due to women's monthly bleeding (ISY) survey: a study of premenstrual symptoms among 5728 women in Europe. Eur J Contracept Reprod Health Care. 2017 Oct;22(5):354-359. doi:10.1080/13625187.2017.1400001. PMID: 29157023.