Ryan Remedios - Taming the autonomic nervous system

ryan remedios

Ryan Remedios © Helmholtz Zentrum München/Carolin Jacklin

Dr. Ryan Remedios is the principal investigator of the Autonomous and Autonomic Systems Group at Helmholtz Pioneer Campus at the Helmholtz Zentrum München since July 2018.

His experimental work established the foundation for experience-driven functional changes in neuronal circuits that in turn determine nervous system functions.

In this interview, he shares his motivation and future ambitions.


What is your main scientific aspiration?

I have uncovered some surprising insights into the activity of a region deep in the brain – called the hypothalamus. It’s known that our life experiences shape our future behaviour. These are learned behaviours. Humans, like other social animals, learn to interact optimally with the environment, and the brain circuits involved in learning and memory are under heavy current investigation. Paradoxically, there is evidence, including the Nobel Prize winning work of Tinbergen, Lorenz and von Frisch, that certain behaviours are genetically encoded, and are performed without prior learning. These are known as instincts or innate behaviours. The brain circuits that control these behaviours were thought to be genetically encoded and organized during brain development.

I want to investigate systems-level nervous system function and further our knowledge of autonomic circuitry, as I have high hopes that a deeper understanding will lead to some revolutionary therapies.

Moreover, I am convinced that bringing together experts from diverse fields helps stimulate inspiration: my ambitions as a neurophysiologist is accentuated by my enthusiastic team which includes an interdisciplinary mix of a medical doctor, a mechanical engineer, a physicist, a veterinarian and a neurobiologist.


Why did you choose to join the HPC?

One of the main reasons I choose HPC is the collaborative, interdisciplinary culture that a city as Munich can offer, and this is one of the reasons why I turned down other attractive offers from European institutions to take up a post at HPC. Also, here I have the complex infrastructures needed to advance my research in the dynamics of neuronal circuit plasticity. I am eager to share my knowledge and my lab’s expertise with my new colleagues in Munich and beyond and I am also looking forward to new avenues for collaboration, with biologists, chemists, physicists, computer scientists and just about anyone with a passion for uncovering the secrets of how the coordinated activity of neurons controls thought, physiology and behaviour.
Only through interdisciplinary collaboration we will be able to fully explore the nervous system in sufficient detail. This, in turn, will enable to reverse or alleviate the degenerative processes that affect us all through illness or just natural ageing.


How are you planning to answer your scientific questions?

The amazing fact I was privileged to observe is that a brief behavioural trigger is all it takes to transform some neurons within a neuronal population into a stable neuronal ensemble with long-lasting implications: the behavioural patterns these circuits control, will be ingrained for a significant portion of a lifetime.

In the study published in Nature, my colleagues and I were exploring mouse social behaviours. I recorded the activity of hundreds of neurons within the hypothalamus in socially interacting mice and discovered an ensemble of neurons active in the presence of males and another active in the presence of females. However, socially inexperienced mice lacked such a separation of ensembles, and the neurons responded to males and females equally. Interestingly the first sexual experience, even if brief, was the trigger that provoked the formation and separation of the male- and female-specific ensembles. Once these ensembles formed, they remained separate and stable for many months.

Our observation that a brief social exposure can trigger a long-lasting functional change within a neuronal population – in my opinion – unlocks the door to an enigmatic universal mechanism. The benefits of uncovering the molecular and cellular mechanisms behind this phenomenon may allow us to control specific circuits and hence facilitate the development of a range of therapies for posttraumatic stress disorder, addiction or influence physiological ageing. Therapies that could reduce the deteriorating effects of ageing on autonomic system function will be a special focus of my new team. As human lifespans keep increasing, I would like for people to live long, with health and dignity!

To achieve these goals I am utilizing a bundle of complementary, cutting-edge technologies. I am a specialist in in vivo electrophysiology and in vivo calcium imaging, wherein I can record, and in the future manipulate, the activity of hundreds of neurons in freely moving and socially interacting mice. My expertise in micro-endoscopic calcium imaging brought recent success by recording the activity of populations of single neurons simultaneously with behaviour. My next objective is to simultaneously record neuronal activity, behaviour and multiple other physiological parameters such as changes in body temperature, heartrate, respiration, and determine how these change with ageing using different mouse models.