Rhythms, Internal States and Homeostasis

Behavioral choices are made not only in response to environmental stimuli, but also based on the internal state of the body in general, and the brain in particular. How are physiological and emotional states, and their variations, perceived and integrated into neural circuits? How do they modify sensory abilities and behavioral actions? These questions are at the heart of the research of different NeuroPSI teams.

Feeling excited or bored, being full of energy or not getting enough sleep, being hungry or thirsty etc., influences our activity, the decisions we make, as well as our ability to learn and remember. We are studying these interactions at different central and peripheral levels. So, how does the internal physiological state affect large-scale neuronal activity in the brain? What are the molecules (hormones, neuropetides, etc.) involved? How is the processing of information in neural networks altered depending on the internal state? Or in the peripheral nervous system, how does the homeostatic synaptic plasticity of the neuromuscular junction continually adjust the strength of motor control during exercise?

From invertebrates to mammals, internal states, brain rhythms, motor commands for body movement come and go in a variety of oscillatory bands spanning periods ranging from less than a second to 24 hours. We seek to understand the nature and alternation of states of wakefulness and sleep, as well as the different cerebral oscillations associated with these states. How does the circadian system and sleep pressure generate sleep-wake rhythms? How are these rhythms synchronized with the day-night cycles? How does an area of the brain generate an oscillation that can spread to the entire brain?

The brain plays a major role in the homeostasis of our body, maintaining the parameters necessary for life, such as our memory, motor commands for body movements or speech, and the correct levels of sugar or oxygen in the blood. In addition, these physiological parameters have a major influence on the functioning of the brain. These cross interactions between the brain and the general physiology of the organism are studied in adults but also during development, with for example the study of the long-term influence of the perinatal environment on the control of energy homeostasis by the hypothalamus.


Astrocytes and Cognition


Neural Code & Auditory Perception

Catherine DEL NEGRO & Jean-Marc EDELINE