Marion E. Frank, Ph.D. Professor Center for Chemosensory Sciences Oral Health & Diagnostic Sciences School of Dental Medicine niversity of Connecticut Graduate Schoo niversity of Connecticut Graduate Schoo MEDS 371: Systems Neuroscience MEDS 371: Systems Neuroscience 2011 2011 Chemosensory Systems Chemosensory Systems
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Marion E. Frank, Ph.D. Professor Center for Chemosensory Sciences Oral Health & Diagnostic Sciences School of Dental Medicine University of Connecticut.
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Marion E. Frank, Ph.D. Professor
Center for Chemosensory SciencesOral Health & Diagnostic Sciences
School of Dental Medicine
University of Connecticut Graduate SchoolUniversity of Connecticut Graduate SchoolMEDS 371: Systems NeuroscienceMEDS 371: Systems Neuroscience
20112011Chemosensory Systems Chemosensory Systems
OLFACTORY SYSTEM
Purpose of Smell---Detect, Analyze Valuable or Dangerous Environmental Chemicals
100s of ChemicalComponents in Scent Representation in FewGlomeruli in Rodents
Few Dominant Cues
Inhibitory Interactions among Glomeruli
Central Olfactory Pathways: Human
Humans:Microsmic~300 OR
Odor Mixtures: Humans
•V = 5 mM vanillin, v = 1 mM vanillin•R = 5 mM PEA, r = 1 mM PEA.• 0 = water •Gold background highlights correct responses of 10 subjects in each session• The 31 adapt-test pairs were presented to each subject in each session •Average % correct Identification for the 2 sessions is listed at right
Convergence of Taste and Smell in Orbitofrontal Cortex
From Rolls, 2004
Olfactory System Summary Smell is a chemical sense that evaluates vaporous environmental chemicals. We perceive many odor qualities, notes perhaps each associated with one of the
hundreds of olfactory receptors (OR). Olfactory sensory neurons (OSN) have dendrites with cilia containing a G-protien-
coupled OR and axons that communicate to the olfactory bulb. OSN can regenerate, giving them an unusual ability to recover from injury. OSN located in separate regions use 4 subfamilies of OR, individual OSN express
single OR variants, and all OSN expressing one of the hundreds of variants project to a few glomeruli in the olfactory bulb.
OSN may respond to many compounds, generating distinct spatial-temporal patterns of neural activity for each odor.
Olfactory bulb output neurons, mitral and tufted cells, relay olfactory signals to higher levels, and periglomerular and granule inhibitory neurons, which are generated throughout adult life, modify olfactory signals within the bulb.
Olfactory signals are relayed from the olfactory bulb to the olfactory paleo-cortex, then thalamus and cerebral cortex, where odor qualities are discriminated.
Projections to the hypothalamus and hippocampus are sites where experience and emotion interact with odor.