The sense of smell allows mammals to perceive a multitude of environmental chemicals as having a distinct odor. It also mediates the detection of pheromones and predator odors that elicit innate responses. How does the olfactory system detect so many different chemicals and how does the nervous system translate those chemicals into diverse perceptions and behaviors? Using a combination of molecular, cellular, and genetic approaches, we have identified families of receptors that initially detect odorants and pheromones in peripheral sense organs, asked how those receptors encode the identities of different chemicals, and investigated how the signals they generate are routed and organized in the nervous system to yield distinct perceptions and instinctive responses.

Research interests in my laboratory focuses on understanding how emotional behavior is encoded in the brain, at the level of specific neuronal circuits, and the specific neuronal subtypes that comprise them. We want to understand the structure and dynamic properties of these circuits and how they give rise to the outward behavioral expressions of emotions such as fear, anxiety or anger. This information will provide a framework for understanding how and where in the brain emotions are influenced by genetic variation and environmental influence (“nature” and “nurture”), and the mechanism of action of drugs used to treat psychiatric disorders such as depression. We are using both mice and the vinegar fly Drosophila melanogaster as model systems. A central focus of the laboratory is on the neural circuits underlying aggression and fear. We are using molecular genetic tools, as well as functional imaging and electrophysiology, to establish cause-and-effect relationships between the activity of specific neuronal circuits and behavior. We hope that this research will lead to new insights into the organization of emotion circuits, and their dysregulation in psychiatric disorders.

The presentation begins with the development of the concept of allosteric proteins and its application to pharmacological receptors. It continues with the identification of the nicotinic acetylcholine receptor, the discovery of its molecular organisation, the structure of the acetylcholine binding site and of the ion channel, and the demonstration of its allosteric transitions. The article then traces the origins of the concept of allosteric modulator and its consequences in pharmacology.The knowledge acquired with the nicotinic receptor is further exploited to reach higher levels of brain organization and the contribution of nicotinic receptors to the action of nicotine on reward and cognition is explored. Theoretical models of cognitive functions and in particular conscious processing are then proposed that link the molecular to the cognitive level.

I have been studying chimpanzees both in the wild and in the laboratory. My talk aims to compare cognitive development in humans and chimpanzees to illuminate the evolutionary origins of human cognition. The upright posture and the bipedal locomotion might be important in human evolution. However, it is the stable supine posture made us human in terms of cognitive development. The human mother–infant relationship is characterized by the physical separation of mother and infant, and the stable supine posture of infants, that enables vocal exchange, face-to-face communication, manual gestures, and object manipulation. Moreover, our study clearly demonstrated that chimpanzees have ultra-short-term working memory capabilities. Taken together, my talk presents a plausible evolutionary scenario for the human characteristics of cognition.