Johan N. Lundstrom, Ph.D. - US grants

DESCRIPTION (provided by applicant): Recent imaging and receptor studies have provided compelling evidence that a processing separation between body odors and non-body odors exists in the olfactory system. In both the visual and auditory systems, stimuli of high social and ecological relevance to the individual receive preferential treatment by perceptual systems and are able to modulate our behavior. Whether the olfactory system organizes stimuli according to this basic principle is not yet known. The overarching goal of this proposal is to establish whether the human brain processes body odors differently from non-body odors and to map the resulting behavioral consequences. The specific aims of this project are: 1) to establish whether exposure to a body odor modulates perception, as predicted by studies of comparative visual social stimuli, and 2) to establish whether body odor processing is preattentive and occurs without conscious recognition. Specifically, we will examine whether body odors are able to modulate physical arousal, neurological responses, and performance in behavioral tasks using, primarily, event-related brain potentials and behavioral measures. The proposed project will deepen our understanding of everyday social communication and widen our knowledge of the mechanisms underlying non- conscious interpersonal social communication. These studies will create groundwork for further investigations into the impact that various forms of olfactory deficits may have on social communication and into the links between those deficits and the mental health problems, such as depression, that afflicted patients often exhibit. PUBLIC HEALTH RELEVANCE: The proposed project will deepen our understanding of the role odors play in human interpersonal social communication. The knowledge gained through these studies may be used to investigate the impact that various forms of olfactory deficits may have on social communication and to explore the links between those deficits and the mental health problems, such as depression, that afflicted patients often exhibit.

Project Summary Chemosensory neuroscience has the ability to acquire relatively non-invasive recordings from all main stages of human olfactory processing but one, the olfactory bulb (OB). This lack of existing recording techniques poses a serious problem for the advancement of our understanding of how the human olfactory system works in health and disease. The General Aim of this application is to establish the first non-invasive method to acquire odorant responses from the human OB in a conscious human. Based on preliminary data, we hypothesize that signals obtained via recordings from electrodes at the nasal bridge represent responses from the olfactory bulb, so-called Electro-Bulbograms (EBG). In this project, we will conduct human subject research to determine if the recorded putative olfactory bulb signal originates from the olfactory receptors. We will utilize paradigms that have been shown in humans and other animals to clearly alter olfactory bulb responses, but not olfactory receptor responses. Moreover, we will determine whether the putative EBG signal originates from the olfactory bulb or from cortical structures by using paradigms demonstrated to alter signal in the cortex but not the olfactory bulb. The project will be performed by a team with a documented familiarity with all procedures, data analyses, and major technical aspects of the proposal. If successful, this innovation would not only enable explorations of the role fulfilled by the olfactory bulb in the human olfactory system but would also be easily implemented as an everyday clinical tool. For example, localizing disease-related changes in human central olfactory processing in neurodegenerative diseases (e.g., Parkinson?s disease) requires information about each stage of the olfactory pathway?information that is currently unobtainable. Thus, a technique allowing measures of human olfactory bulb signals will greatly aid future olfactory-related translational work.