CNS Control of Peripheral Mitochondrial Form and Function: Mitokines
My laboratory has made an intriguing discovery that mitochondrial stress in one tissue can be communicated to distal tissues. We find that mitochondrial stress in the nervous system triggers the production of entities known as mitokines. These mitokines are discharged from the nervous system, orchestrating a response in peripheral tissues that extends the lifespan of C. elegans. The revelation came as a surprise, given the prevalent belief that cell autonomous mechanisms would underlie the relationship between mitochondrial function and aging. It was also surprising given the prevailing dogma that mitochondrial function must be increased, not decreased, to improve health and longevity. Our work also underscores the fact that mitochondria, which originated as a microbial entity and later evolved into an intracellular symbiont, have retained their capacity for intercommunication, now facilitated by signals from the nervous system. We hypothesize that this communication has evolved as a mechanism to reduce infection from pathogens.
Feedback control in the nervous system: from cells and circuits to behaviour
The nervous system is fundamentally a closed loop control device: the output of actions continually influences the internal state and subsequent actions. This is true at the single cell and even the molecular level, where “actions” take the form of signals that are fed back to achieve a variety of functions, including homeostasis, excitability and various kinds of multistability that allow switching and storage of memory. It is also true at the behavioural level, where an animal’s motor actions directly influence sensory input on short timescales, and higher level information about goals and intended actions are continually updated on the basis of current and past actions. Studying the brain in a closed loop setting requires a multidisciplinary approach, leveraging engineering and theory as well as advances in measuring and manipulating the nervous system. I will describe our recent attempts to achieve this fusion of approaches at multiple levels in the nervous system, from synaptic signalling to closed loop brain machine interfaces.
The embodied brain
Understanding the brain is not only intrinsically fascinating, but also highly relevant to increase our well-being since our brain exhibits a power over the body that makes it capable both of provoking illness or facilitating the healing process. Bearing in mind this dark force, brain sciences have undergone and will undergo an important revolution, redefining its boundaries beyond the cranial cavity. During this presentation, we will discuss about the communication between the brain and other systems that shapes how we feel the external word and how we think. We are starting to unravel how our organs talk to the brain and how the brain talks back. That two-way communication encompasses a complex, body-wide system of nerves, hormones and other signals that will be discussed. This presentation aims at challenging a long history of thinking of bodily regulation as separate from "higher" mental processes. Four centuries ago, René Descartes famously conceptualized the mind as being separate from the body, it is time now to embody our mind.
The embodied brain
Understanding the brain is not only intrinsically fascinating, but also highly relevant to increase our well-being since our brain exhibits a power over the body that makes it capable both of provoking illness or facilitating the healing process. Bearing in mind this dark force, brain sciences have undergone and will undergo an important revolution, redefining its boundaries beyond the cranial cavity. During this presentation, we will discuss about the communication between the brain and other systems that shapes how we feel the external word and how we think. We are starting to unravel how our organs talk to the brain and how the brain talks back. That two-way communication encompasses a complex, body-wide system of nerves, hormones and other signals that will be discussed. This presentation aims at challenging a long history of thinking of bodily regulation as separate from "higher" mental processes. Four centuries ago, René Descartes famously conceptualized the mind as being separate from the body, it is time now to embody our mind.
Microbiota in the health of the nervous system and the response to stress
Microbes have shaped the evolution of eukaryotes and contribute significantly to the physiology and behavior of animals. Some of these traits are inherited by the progenies. Despite the vast importance of microbe-host communication, we still do not know how bacteria change short term traits or long-term decisions in individuals or communities. In this seminar I will present our work on how commensal and pathogenic bacteria impact specific neuronal phenotypes and decision making. The traits we specifically study are the degeneration and regeneration of neurons and survival behaviors in animals. We use the nematode Caenorhabditis elegans and its dietary bacteria as model organisms. Both nematode and bacteria are genetically tractable, simplifying the detection of specific molecules and their effect on measurable characteristics. To identify these molecules we analyze their genomes, transcriptomes and metabolomes, followed by functional in vivo validation. We found that specific bacterial RNAs and bacterially produced neurotransmitters are key to trigger a survival behavioral and neuronal protection respectively. While RNAs cause responses that lasts for many generations we are still investigating whether bacterial metabolites are capable of inducing long lasting phenotypic changes.
Brain Awareness Week @ IITGN
Traumatic injury in the nervous system leads to devastating consequences such as paralysis. The regenerative capacity of the nervous system is limited in adulthood. In this talk, Dr. Anindya would be sharing how the simple nematode C. elegans with its known connectome can inform us about the biology of nervous system repair.
Plasticity of Pain and Pleasure
What happens when the nervous system fails to adapt? Our perception of the world relies on a nervous system that learns and adapts to sensory information. Based on our experience we can predict what a wooden surface will feel like, that fire is hot, and that a gentle caress from a partner can be soothing. But our sensory experience of the world is not static – warm water can feel like fire on sunburned skin and the gentle brush of our clothes can be excruciating after an injury. In pathological conditions such as chronic pain, changes in nervous system function can cause normally innocuous sensory stimuli to be perceived as aversive or painful long after the initial injury has happened. These changes can sometimes be similar to the formation of a pain ‘memory’ that can modulate and distort our perception of sensory information. Our research program seeks to understand how fundamental processes that govern the formation and maintenance of plastic changes in the nervous system can lead to pathological conditions and how we can reverse engineer these changes to treat chronic conditions.