An animal model of central auditory pathway imaging in the rat brain by high resolution small animal positron emission tomography.
CONCLUSIONS
Our study demonstrated that high resolution animal positron emission tomography (PET) can non-invasively assess the change in glucose metabolism of the central auditory pathway including the inferior colliculus and auditory cortex in the rat.


OBJECTIVE
The traditional in vitro approach with immunohistochemical staining or autoradiography to assess chronological changes or topographic arrangement of central auditory pathway required sacrificing a large number of animals. Inter-individual difference is also a major concern. Therefore, development of an in vivo animal model using PET imaging would be a rational method to overcome these shortcomings.


METHODS
Small animal PET scan using (18)F-fluorodeoxyglucose (FDG) as a functional marker was performed in rats. Each animal was serially scanned before and after unilateral cochlear ablation, with and without acoustic stimulation. The images were analyzed by the region of interest (ROI) method. Ratios of radioactivity at the inferior colliculus and auditory cortex and a referenced cerebral cortex between bilateral hemispheres were measured.


RESULTS
These scans demonstrated several brain structures including the inferior colliculus (IC) and cortex (B). Moreover, unilateral cochlear ablation decreased the radioactivity at contralateral IC and auditory cortex (C) areas. Differences may reach 33% in IC and 27% in C, and average radioactivity ratios were 1.24+/-0.08 and 1.18+/-0.07 in selected adjacent sections, respectively.
Hsu
Wei-Chung
WC
Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan.
Tzen
Kai-Yuan
KY
Huy
Patrice Tran Ba
PT
Duet
Michele
M
Yeh
Te-Huei
TH
D000161:Acoustic Stimulation; D000818:Animals; D001303:Auditory Cortex / Q000000981:diagnostic imaging*; D001306:Auditory Pathways / Q000000981:diagnostic imaging*; D004195:Disease Models, Animal; D016057:Evoked Potentials, Auditory, Brain Stem; D005260:Female; D019788:Fluorodeoxyglucose F18; D046088:Hearing Loss, Unilateral / Q000000981:diagnostic imaging*; D007245:Inferior Colliculi / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D051381:Rats; D017207:Rats, Sprague-Dawley
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18