title: A human chemosignal modulates frontolimbic activity and connectivity in response to emotional stimuli.
abstract: Evidence suggests the putative human pheromone Δ4,16-androstadien-3-one (androstadienone), a natural component of human sweat, increases attention to emotional information when passively inhaled, even in minute amounts. However, the neural mechanisms underlying androstadienone's impact on the perception of emotional stimuli have not been clarified. To characterize how the compound modifies neural circuitry while attending to emotional information, 22 subjects (11 women) underwent two fMRI scanning sessions, one with an androstadienone solution and one with a carrier control solution alone on their upper lip. During each session, participants viewed blocks of emotionally positive, negative, or neutral images. The BOLD response to emotional images (relative to neutral images) was greater during exposure to androstadienone in right orbitofrontal and lateral prefrontal cortex, particularly during positive image blocks. Androstadienone did not impact the response to social images, compared to nonsocial images, and results were not related to participant sex or olfactory sensitivity. To examine how androstadienone influences effective connectivity of this network, a dynamic causal model was employed with primary visual cortex (V1), amygdala, prefrontal cortex, and orbitofrontal cortex on each side. These models indicated that emotional images increased the drive from V1 to the amygdala during the control session. With androstadienone present, this drive to amygdala was decreased specifically for positive images, which drove downstream increases in orbitofrontal and prefrontal activity. This evidence suggests that androstadienone may act as a chemical signal to increase attention to positively valenced information via modifications to amygdala connectivity.
authors: Department of Psychiatry, Indiana University School of Medicine, United States. Electronic address: thummer@iupui.edu.
authors: Tom A
authors: TA
authors: Hummer
authors: Department of Psychiatry, University of Illinois at Chicago and Mental Health Service Line, Jesse Brown VA, Chicago, IL, United States.
authors: K Luan
authors: KL
authors: Phan
authors: Institute for Mind and Biology and Department of Comparative Human Development, The University of Chicago, United States.
authors: David W
authors: DW
authors: Kern
authors: Institute for Mind and Biology and Department of Comparative Human Development, The University of Chicago, United States; Department of Psychology, The University of Chicago, United States.
authors: Martha K
authors: MK
authors: McClintock
mesh_terms: D000293:Adolescent; D000328:Adult; D000679:Amygdala / Q000000981:diagnostic imaging / Q000187:drug effects / Q000502:physiology; D000730:Androstadienes / Q000008:administration & dosage / Q000494:pharmacology*; D001288:Attention / Q000187:drug effects*; D004644:Emotions / Q000187:drug effects*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D049049:Pheromones, Human / Q000008:administration & dosage / Q000494:pharmacology*; D017397:Prefrontal Cortex / Q000000981:diagnostic imaging / Q000187:drug effects / Q000502:physiology; D012938:Social Perception; D055815:Young Adult
chemical_list: D000730:Androstadienes; D049049:Pheromones, Human
keywords: Amygdala; Androstadienone; Attention; Emotion; Pheromone; Prefrontal cortex; fMRI