title: c-Fos expression in the parabrachial nucleus following intraoral bitter stimulation in the rat with dietary-induced zinc deficiency.
abstract: Zinc deficiency causes various symptoms including taste disorders. In the present study, changes in expression of c-Fos immunoreactivity in neurons of the parabrachial nucleus (PBN), one of the relay nuclei for transmission of gustatory information, after bitter stimulation to the dorsal surface of the tongue were examined in zinc-deficient rats. Experimental zinc-deficient animals were created by feeding a low-zinc diet for 4weeks, and showed the following symptoms of zinc deficiency: low body weight, low serum zinc content and behavioral changes to avoid bitter stimulation. In normal control animals, intraoral application of 1mM quinine caused increased numbers of c-Fos-immunoreactive (c-Fos-IR) neurons in the external lateral subnucleus and external medial subnucleus of the PBN (elPBN and emPBN, respectively) compared with application of distilled water. However, in the zinc-deficient animals, the numbers of c-Fos-IR neurons in the elPBN and emPBN did not differ significantly between application of quinine and distilled water. After feeding the zinc-deficient animals a normal diet for 4weeks, the symptoms of zinc deficiency recovered, and the expression of c-Fos-IR neurons following intraoral bitter stimulation became identical to that in the normal control animals. The present results indicate that dietary zinc deficiency causes alterations to neuronal activities in the gustatory neural circuit, and that these neuronal alterations can be reversed by changing to a normal diet.
authors.affiliation: Department of Oral Anatomy and Developmental Biology, Osaka University Graduate School of Dentistry, Japan; Department of Dental Anesthesiology, Osaka University Graduate School of Dentistry, Osaka, Japan. Electronic address: akawano@dent.osaka-u.ac.jp.
authors.forename: Akiyo
authors.initials: A
authors.lastname: Kawano
authors.affiliation: Department of Oral Anatomy and Developmental Biology, Osaka University Graduate School of Dentistry, Japan.
authors.forename: Shiho
authors.initials: S
authors.lastname: Honma
authors.affiliation: Department of Oral Anatomy and Developmental Biology, Osaka University Graduate School of Dentistry, Japan.
authors.forename: Chizuko
authors.initials: C
authors.lastname: Inui-Yamamoto
authors.affiliation: Department of Oral Anatomy and Developmental Biology, Osaka University Graduate School of Dentistry, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Ito
authors.affiliation: Department of Dental Anesthesiology, Osaka University Graduate School of Dentistry, Osaka, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Niwa
authors.affiliation: Department of Oral Anatomy and Developmental Biology, Osaka University Graduate School of Dentistry, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Wakisaka
mesh_terms: D000821:Animal Feed; D000818:Animals; D004032:Diet; D004195:Disease Models, Animal; D005518:Food Preferences / Q000502:physiology; D007150:Immunohistochemistry; D008297:Male; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D065823:Parabrachial Nucleus / Q000378:metabolism* / Q000473:pathology; D010812:Physical Stimulation; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D011803:Quinine / Q000008:administration & dosage; D017207:Rats, Sprague-Dawley; D013651:Taste Disorders / Q000209:etiology* / Q000378:metabolism* / Q000473:pathology; D055697:Taste Perception / Q000502:physiology*; D015032:Zinc / Q000097:blood / Q000172:deficiency*
chemical_list: D016760:Proto-Oncogene Proteins c-fos; D011803:Quinine; D015032:Zinc
keywords: Bitter; Parabrachial nucleus; Taste disorder; Zinc-deficiency; c-Fos