Brain Ponderings podcast with Dr. Mark Mattson

Professor Jeffrey Macklis of Harvard University describes how different types of neurons in the cerebral cortex arise from progenitor [stem] cells and how those neurons grow and make highly specific connections with other neurons.. His findings in animal models have shown that it is possible to replace neurons lost as a result of traumatic injury or neurodegenerative conditions such as ALS and Alzheimer's disease.

Professor James Knierim of Johns Hopkins University describes how the brain processes visual information in ways that enable us to accurately navigate through our environment and remember what we experience during our journeys. Discoveries made during the past several decades have revealed that neuronal circuits in two intimately connected brain regions – the entorhinal cortex and hippocampus – are key to the 'brain's GPS' and the generation of 'cognitive maps'. These neuronal circuits are of fundamental importance in learning and memory and are the first to degenerate in Alzheimer's disease.

Professor Hey-Kyoung Lee of Johns Hopkins University describes how the brain's neuronal networks reorganize themselves in response to sensory deficits such as blindness and deafness. In blind people neuronal circuits in the visual cortex become responsive to sounds and touch. By recording electrical activity in individual neurons in the visual cortex of mice kept in complete darkness she discovered that some synaptic connections between neurons become stronger. Interestingly, temporary deafening of mice results in increased strength of synapses in the visual cortex. The latter finding suggests that it may be possible to enhance recovery of brain function after an injury to one sensory system by temporarily depriving input from a different sensory system.

Professor Jonathan Kipnis of the Washington University School of Medicine talks about the brain's immune system. He and is students and postdocs have provided evidence that cells of the immune system are critical for protecting neurons of the brain and spinal cord against traumatic injury, and that 'protective autoimmunity' can also be beneficial for the brain in animal models of multiple sclerosis and autism. Their discoveries have also revealed important roles for a type of T lymphocyte in learning and memory, anxiety, and social behaviors. Dr. Kipnis recently discovered that the brain has its own lymphatic system that functions as a drainage system through which molecular waste is removed. This lymphatic system may become clogged during aging which may contribute to the accumulation of toxic amyloid in the brain in Alzheimer's disease. He discusses the implications of his research findings for the prevention and treatment of neurological disorders.

What determines whether we make good or bad decisions? Professor Michael Platt of the University of Pennsylvania is a biological anthropologist, neuroscientist, and neuroeconomist whose research has elucidated the neuronal networks involved in decision-making. By recording electrical activity in neurons of non-human primates while they are making decisions Platt has shown that circuits in prefrontal cortex and adjacent cingulate gyrus are particularly important in decision-making. More recently he has been applying his knowledge of the neurobiology of decision-making to help businesses enhance their productivity.

Sarkis Mazmanian is a professor of microbiology at the California Institute of Technology. Research in his laboratory has provided evidence that bacteria in the intestines play important roles in the normal development and function of the immune and nervous systems. His findings suggest roles for certain gut bacteria in the pathogenesis of autoimmune disorders and Parkinson's disease. He discovered that one species of gut bacteria can improve immune function and can ameliorate behavioral abnormalities in an animal model of autism.

Art Kramer is a Professor of Psychology and the Director of the Center for Cognitive Brain Health at Northeastern University. In this podcast he talks about how aerobic exercise can improve several aspects of brain performance including learning and memory, and multitasking. His brain imaging studies in elderly people have shown that exercise can increase the amounts of gray and white matter in some brain regions, and can enhance the functional connectivity of neuron networks. Importantly, exercise improves academic performance in children. On the other hand lack of exercise and overeating adversely affect brain structure and performance.

In a captivating discussion, Professor Charles Nelson III, a pediatric and neuroscience expert at Harvard, delves into the intricacies of brain development and the impact of early adversities. He shares insights from his research on childhood neglect and trauma, revealing how they can lead to lifelong health issues. With studies spanning Romania, Bangladesh, and Hungary, he highlights the critical timing of interventions and the effects of prenatal factors on brain growth. Nelson also explores links between executive function and language development, unraveling the complex fabric of childhood adversity.

Professor Guo-Li Ming talks about how the neuronal networks are formed during brain development. She and others have developed technologies that enable the formation of brain organoids ('mini-brains') from human pluripotent stem cells. Guo=Li has used such brain organoids to elucidate how the brain normally develops and what goes wrong in developmental brain disorders including schizophrenia and autism. She has also provided evidence that by infecting neural stem cells, ZIKA virus and COVID-19 viruses may adversely affect the brain. Professor Ming's laboratory website: https://www.med.upenn.edu/minglab/

Professor Franz Vollenweider of the University of Zurich is psychiatrist and neuroscientist who has been at the forefront of research on drugs that induce altered states of consciousness. Using state of the art brain imaging technologies, pharmacological tools, and psychological evaluations, he and his research team have made major advances toward a clear understanding the neurobiological basis of the psychedelic experience. Here talks about how psychedelic chemicals such as psilocybin, LSD, and ketamine affect neuronal network excitability in ways that elicit hallucinations and altered states of brain function. He also talks about the emerging evidence that psychedelics can be very beneficial for people with depression and may also facilitate recovery from addiction to alcohol and other drugs.