Biophysics, Physiology, and some Psychology 

Shimon Marom ( شمعون ماروم /  שמעון מרום ) is a Professor of Physiology (MD, PhD), and the Pearl Seiden Chair in Sciences, Newtork Biology Research Labs, Technion –– Israel Institute of Technology. 

*For a short bio, please click to expand this cell. 

Professor of Physiology, and the Pearl Seiden Academic Chair of Sciences at the Technion–Israel Institute of Technology. Completed basic training (MD, PhD) at the Technion, and a postdoctoral training (Fulbright & Fishbach fellowship) at Brandeis University (Mass., USA). Returned to the Technion (Alon Fellow) in 1993, and serves as a Faculty there to date. Focuses on theoretical and experimental analyses of the self-organization of bio-electrical phenomena in proteins, cells, and networks embedded in responsive and adaptive environments, implementing closed-loop experimental designs and natural input statistics. Over the years, headed the Physiology & Biophysics department, the Technion Program for Excellence, dean of medicine, and the Technion Executive Vice President for Academic Affairs. As of 2023, serves as the Director of the Samuel Neaman institute.

The current state of affairs is exposing the weakness of the Israeli leadership and its horrific price. We will rise to the challenge, but it is clear that supporting Netanyahu’s continued tenure reflects a deep moral and ethical decay
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מצבה של החברה והמדינה חושף את דלות המנהיגות בישראל ומחירה הנורא. נעמוד באתגר, אך ברי כי תמיכה בהמשך כהונת נתניהו משקפת ניוון עמוק של מוסר וערכים

Research Interest:

– Electrical phenomena in neural networks, cells and proteins: dynamics and function
– Relational space for dialogue between physiology and dynamic psychology.

Currently active research: Excitability in extended cortical axonal arbors, measured using state-of-the-art high-density CMOS-based multi-electrode arrays.

*Motivated students and postdocs interested to join the team are invited to email marom at Technion dot ac do il

Action potential propagation in central axons – complicated trees characterized by cascades of branching points – raise several fundamental biophysical and physiological questions, one of which (long-standing) is at the heart of the experimental research program: Do axons introduce consistent activity-dependent spatial and (or) temporal effects as they conduct the action potentials through series of branching points? 

Addressing this issue in thin, un-myelinated, millimeter scale long axons entails a challenge of measurement and signal processing. The study focuses on exploring action potential propagation in unmyelinated cortical axons. Utilizing in-vitro high-density micro-electrode array techniques, the study aims to identify relations between the statistical features of neuronal and network activity, and the probabilities of action potential invasion into deep axonal branches of different order (number of branching points on the way), axonal length, and action potential velocity.

Activity-based micrograph of a single neuron axonal tree

Multiple axonal spikes 

On membrane excitability: theory & measurements

The study of excitability, from Galvani and Helmholtz, through Adrian, Hodgkin and Huxley, Neher and Sakmann, all the way to McKinnon’s elucidation of a channel protein structure, should no-doubt make us physiologists very proud of our discipline. But there is still a long way to go. Present concepts and technologies make it possible to implement the biophysical understanding of excitability in the more general context of mechanisms underlying the emergence and maintenance of functional cellular organization. Accordingly, the body of our theoretical and experimental studies reflects the idea of membrane excitability as a toy model for self-organization of cellular function. These studies address parameterisation of high-dimensional models of excitability, adaptation over extended ranges of time scales, critical self-organization, multiplicity of system states and its impacts on scaling of rates, modeling state-dependent processes, response entrainment, resilience of function to parametric variations, and more.

On neural networks: dynamics & function

It is generally believed that behaviors are not mapped to single spikes generated by any one neuron, but rather to groups of spikes. These functional spiking neural activity groups may originate from a single neuron or from populations of neurons firing in synchronic or diachronic manners. The structure of the vast majority of behaviorally relevant neural activity groups is not predetermined by genetics, nor dictated by some sort of an ‘all-knowing teacher’, homunculus. Rather, neural activity groups are formed and modulated throughout life in a dynamic, activity-dependent manner, conforming to evolution and environmental constraints. The formation of neural activity groups is learning; their conservation is memory. 

Of the various alternatives, large random cortical networks developing ex vivo are probably the most appropriate experimental model systems for studying the universals governing formation, adaptation, and conservation of neural activity groups. These networks demonstrate extensive functional connectivity and sensitivity of that connectivity to activity. Moreover, the networks are relatively free of predefined constraints and intervening variables. Alternative experimental models (acute in-vivo, or acute in-vitro) allow one to explore ‘what-is-there’, but not ‘how-it-got-to-be-there’. The latter question is tightly related to development.

The body of our network studies implements advanced electronic (multi-electrode array) to interface with large scale developing cortical neural networks. These studies address learning under closed loop settings, adaptation over extended ranges of time scales, stimulus representation, embodiment, dynamics over structure, neuromodulation, impacts of modularity, and more. 

On Space for Dialogue between depth psychology and physiology

Out of a developing sense of unease with the nature of the present dialogue between brain science and psychology, I sought understanding, not so much of this or that recent biological finding, but of the roots that feed the stance of neurophysiology toward depth psychology.  While meandering in the chasm between physiology and psychology, contemplating the recent history of possible-impossible relations, the text evolved into an essay, a monograph titled Science, Psychoanalysis, and the Brain: Space for Dialogue (Cambridge University Press [read online], download; תרגום לעברית; Italian translation). The essay is an invitation, issued by a practicing physiologist, intended for dynamically oriented theory-sensitive psychologists and physiologists. It became an invitation to a space where reflections on neurophysiology are expressed and guided by depth psychology in mind; a space where neurophysiology resumes its traditional, humbled attitude toward matters of the psyche, and where the intellectual autonomy of depth psychology is acknowledged. The underlying assumption is that in the basic sense, as opposed to the applied science sense, the meaning of neurophysiological and neuroanatomical observables resides in their interpretation in light of psychological theories. A dialogue based on such terms, where psychology provides a theoretical framework that contributes to physiology, is beneficial to both parties: Neurophysiology gains something that is currently wanted – constraints and guidelines in phrasing meaningful questions. Psychology might gain further motivation to crystalize its multifaceted concepts. At all events, both camps might enrich the spectrum of metaphors available to them within their own disciplinary realms. 

Outreach

Short essays on a range of topics (Science, Medicine, Education, Academy and Society):