Portal:Complex Systems Digital Campus/E-Laboratory on Physiological Functions

Portal:Complex_Systems_Digital_Campus/E-Laboratory_on_Physiological Functions Physiological function

Physiological functions result from the integration of cells, tissues and organ properties in the context of the whole organism interacting with its environment. A complex system approach of physiological functions should lead to an iterated cycle combining relevant measurements and experimentation, modeling and simulation. Such a goal requires building multimodal investigation devices for simultaneous in vivo recording at different spatial and temporal scales of relevant parameters as well as designing theoretical methods and tools for appropriate modeling and computer simulation.

Grand challenges:

1. Integrating multimodal measurements and observations of physiological activities at different spatial and temporal scales. 2. Characterizing the contextual features determining the onset of operation, maintenance and modulation of a physiological function. 3. Investigating the relationship between the ontogenesis of a physiological function and its potential disorders.

Expected results include the design of new investigation devices and theoretical methods and tools for observing, modeling, understanding and then possibly controlling physiological functions. 1. Integrating multimodal measurements and observations of physiological activities at different spatial and temporal scales. An integrated observation of sub cellular and supra cellular processes requires to either: (i) Translate in the same spatial and temporal referential heterogenous data recorded in the same organism but at different moments, or (ii) Design new devices capable of simultaneously recording multimodal data. The first goal can be achieved through available methods going from spatio-temporal matching to data fusion. These methods are limited by recalibration problems and errors (whatever the rigid or elastic transformations applied). The second option would be a real breakthroug providing a generation of totally new instrumentation offering instantaneously access to essential structural and dynamic variables (chemical, electrical, mechanical, etc.) at all relevant spatio temporal scales. This trend can be exemplified by macroscopic data acquisition in medical imaging with optical-PET and PET-CT devices and, for vital physiological variables, by ambulatory integrated sensors providing real-time patient state tracking in a normal environment. In the domain of vegetal biology, phenotypic plant platforms lead to the observation of flow from roots to leaves at different time scales. Integrating such synchronous, multimodal, multiscale observations in relevant models should provide a good basis for the reconstruction of physiological functions. 2. Characterizing the contextual features determining the onset of operation, maintenance and modulation of a physiological function. The objective is here to view the function as an integration of subfunctions that should be investigated from different perspectives or using perturbative and comparative approaches. Different factors or conditions such as resting versus moving, diet-nutrition, training, can influence and move the system towards new functioning modes. Comparative physiology provides a way to study the conservation or divergence of physiological functions. This approach is relevant for respiration and locomotion in the animal kingdom as well as for fruit maturation in the field of vegetal biology. Physiological functions should be characterized through the extraction of high-level variables, i.e “thermodynamics variables”? along the lines of allometry i.e. preservation of characteristics over the size variations). More generally, we should be able to define invariants (or invariant relationships) attached to physiological functions and the conditions for their conservation.	3. Investigating the relationship between the ontogenesis of a physiological function and its potential disorders. Physiological functions should be explored through their set up during ontogenesis, maturation and maintenance during growth, adulthood and ageing. The dynamical behavior of physiological functions should be explored as well during pathological events.

Examples: · Heart embryology: progressive formation of anatomical structures and functional patterns with ill-posed problems related to the partial observations at our disposal (i.e interpolation of highly structurally variable objects from the architectonic viewpoint, installation of nodal tissue functions or sinusal electric waves, etc.) · Schizophrenia: effects on the highest cognitive levels of the modifications induced by the disease at the level of more elementary neurological functions