Use of thallium transport to visualize functional olfactory nerve regeneration in vivo.
OBJECTIVE
To image olfactory nerve regeneration in vivo using a high-resolution gamma cam- era and radiography after nasal administration of thallium-201 (olfacto-scintigraphy).


METHODS
Six Wistar rats were trained to avoid the smell of cycloheximide as a test of olfactory function. The olfactory nerve fibers of 3 rats were then carefully transected bilaterally with a Teflon knife, avoiding damage to the olfactory bulbs. The remaining 3 rats underwent sham operations and were used as controls. Steel wires were implanted in the left olfactory bulb of each rat for locating the bulbs with plain X-rays. The rats were assessed 2, 14, 28, and 42 d after the olfactory nerve transection or sham operation for their ability to detect odours and for transport of 201Tl to the olfactory bulb area 8 h after nasal administration of 201Tl.


RESULTS
Both transport of 201Tl to the olfactory bulb area (p < 0.04) and ability to detect odours (p < 0.04) significantly increased with a time course after olfactory nerve transection.


CONCLUSIONS
201Tl transport to the olfactory bulb may be useful to visually assess olfactory ability in vivo. We plan to test olfacto-scintigraphy clinically by nasal administration of 201Tl in patients with posttraumatic olfactory loss.
Shiga
Hideaki
H
Department of Otorhinolaryngology - Head and Neck Surgery, Kanazawa University, Kahokugun, Ishikawa, Japan. shigah@kanazawa-med.ac.jp
Washiyama
Kohshin
K
Hirota
Kyoko
K
Amano
Ryohei
R
Furukawa
Mitsuru
M
Miwa
Takaki
T
D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D015902:Gamma Cameras; D009416:Nerve Regeneration; D009812:Odorants; D009832:Olfactory Nerve / Q000502:physiology* / Q000601:surgery; D051381:Rats; D017208:Rats, Wistar; D020127:Recovery of Function; D012903:Smell / Q000502:physiology*; D013794:Thallium Radioisotopes / Q000378:metabolism
D013794:Thallium Radioisotopes