title: Enhancement of Odor-Induced Activity in the Canine Brain by Zinc Nanoparticles: A Functional MRI Study in Fully Unrestrained Conscious Dogs.
abstract: Using noninvasive in vivo functional magnetic resonance imaging (fMRI), we demonstrate that the enhancement of odorant response of olfactory receptor neurons by zinc nanoparticles leads to increase in activity in olfaction-related and higher order areas of the dog brain. To study conscious dogs, we employed behavioral training and optical motion tracking for reducing head motion artifacts. We obtained brain activation maps from dogs in both anesthetized state and fully conscious and unrestrained state. The enhancement effect of zinc nanoparticles was higher in conscious dogs with more activation in higher order areas as compared with anesthetized dogs. In conscious dogs, voxels in the olfactory bulb and hippocampus showed higher activity to odorants mixed with zinc nanoparticles as compared with pure odorants, odorants mixed with gold nanoparticles as well as zinc nanoparticles alone. These regions have been implicated in odor intensity processing in other species including humans. If the enhancement effect of zinc nanoparticles observed in vivo are confirmed by future behavioral studies, zinc nanoparticles may provide a way for enhancing the olfactory sensitivity of canines for detection of target substances such as explosives and contraband substances at very low concentrations, which would otherwise go undetected.
authors.affiliation: AU MRI Research Center, Department of Electrical & Computer Engineering, Auburn University, Auburn, AL 36832, USA, College of Information Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Jia
authors.affiliation: Department of Anatomy, Physiology & Pharmacology, Auburn University, Auburn, AL 36832, USA.
authors.forename: Oleg M
authors.initials: OM
authors.lastname: Pustovyy
authors.affiliation: AU MRI Research Center, Department of Electrical & Computer Engineering, Auburn University, Auburn, AL 36832, USA.
authors.forename: Yun
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Canine Detection Research Institute, Auburn University, Auburn, AL 36832, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Waggoner
authors.affiliation: AU MRI Research Center, Department of Electrical & Computer Engineering, Auburn University, Auburn, AL 36832, USA.
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Beyers
authors.affiliation: Department of Clinical Sciences, Auburn University, Auburn, AL 36832, USA.
authors.forename: John
authors.initials: J
authors.lastname: Schumacher
authors.affiliation: MRRA Inc., Euless, TX 76040, USA.
authors.forename: Chester
authors.initials: C
authors.lastname: Wildey
authors.affiliation: Department of Anatomy, Physiology & Pharmacology, Auburn University, Auburn, AL 36832, USA.
authors.forename: Edward
authors.initials: E
authors.lastname: Morrison
authors.affiliation: MR R&D, Siemens Healthcare, Malvern, PA 19355, USA.
authors.forename: Nouha
authors.initials: N
authors.lastname: Salibi
authors.affiliation: AU MRI Research Center, Department of Electrical & Computer Engineering, Auburn University, Auburn, AL 36832, USA, Department of Psychology, Auburn University, Auburn, AL 36832, USA and Alabama Advanced Imaging Consortium, Auburn University and University of Alabama Birmingham, AL, USA.
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Denney
authors.affiliation: Department of Anatomy, Physiology & Pharmacology, Auburn University, Auburn, AL 36832, USA, gopi@auburn.edu vodyavi@auburn.edu.
authors.forename: Vitaly J
authors.initials: VJ
authors.lastname: Vodyanoy
authors.affiliation: AU MRI Research Center, Department of Electrical & Computer Engineering, Auburn University, Auburn, AL 36832, USA, Department of Psychology, Auburn University, Auburn, AL 36832, USA and Alabama Advanced Imaging Consortium, Auburn University and University of Alabama Birmingham, AL, USA gopi@auburn.edu vodyavi@auburn.edu.
authors.forename: Gopikrishna
authors.initials: G
authors.lastname: Deshpande
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000502:physiology*; D001931:Brain Mapping; D003243:Consciousness / Q000502:physiology*; D004285:Dogs; D008279:Magnetic Resonance Imaging; D053768:Metal Nanoparticles / Q000008:administration & dosage*; D009812:Odorants; D018034:Olfactory Receptor Neurons / Q000502:physiology; D015032:Zinc / Q000008:administration & dosage* / Q000494:pharmacology
chemical_list: D015032:Zinc
keywords: awake animal imaging; dogs; functional magnetic resonance imaging; olfactory system; zinc nanoparticles