title: Asymmetrical intersection between the middle cerebral artery and rhinal vein suggests asymmetrical gustatory cortex location in rodent hemispheres.
abstract: The rodent gustatory cortex is located in the anterior part of the insular cortex, which is near the dorsal part of the rhinal vein (RHV) and the intersection of the anterior and posterior regions of the middle cerebral artery (MCA). Thus, the intersection between the RHV and MCA is used as a landmark for the rodent gustatory cortex. In our previous study, we employed functional magnetic resonance imaging (MRI) to demonstrate that tastants evoked bilateral responses in the rodent insular cortices, but that these representations were asymmetrical between the hemispheres. In the present study, to clarify the observed asymmetrical responses, we performed magnetic resonance angiography in a 7.0-Tesla MRI scanner to determine the anatomical position of the rodent gustatory cortex, which was identified using the intersection of the MCA and RHV. We successfully observed the intersection while administering carbogen as an inhaled gas and found that the intersection in the left hemisphere is more anterior compared to that in the right hemisphere. Taken together with the previous functional MRI results, this result indicates that the gustatory representation in relation to the intersection may be identically conserved in the insular cortex of both hemispheres; therefore, the rodent gustatory cortex may be asymmetrically located between the left and right hemispheres. The result also suggests that this landmark location needs to be verified when investigating gustatory representations and responses.
authors.affiliation: Center for Information and Neural Networks, National Institute of Information and Communications Technology, Suita, Osaka 565-0871, Japan; Department of Investigative Radiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka 565-8586, Japan. Electronic address: ikuhiro.kida@nict.go.jp.
authors.forename: Ikuhiro
authors.initials: I
authors.lastname: Kida
authors.affiliation: Department of Investigative Radiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka 565-8586, Japan.
authors.forename: Jun-Ichiro
authors.initials: J
authors.lastname: Enmi
authors.affiliation: Department of Investigative Radiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka 565-8586, Japan.
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Iida
authors.affiliation: Center for Information and Neural Networks, National Institute of Information and Communications Technology, Suita, Osaka 565-0871, Japan; Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan.
authors.forename: Yoshichika
authors.initials: Y
authors.lastname: Yoshioka
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000033:anatomy & histology* / Q000098:blood supply; D018810:Magnetic Resonance Angiography; D008297:Male; D020768:Middle Cerebral Artery; D009666:Nose / Q000098:blood supply; D017207:Rats, Sprague-Dawley; D013649:Taste / Q000502:physiology*; D014680:Veins
keywords: Gustatory cortex; Insular cortex; Magnetic resonance angiography; Rodent brain; Taste