SOMATOSENSORY SYSTEMS, PAINOptical imaging of excitation propagation evoked by stimulation to the trigeminal caudalisSeo, KenjiCA; Fujiwara, Naoshi1; Takeuchi, Kiichi2; Maeda, Takeyasu2; Someya, GenjiAuthor Information Division of Dental Anesthesiology, Department of Tissue Regeneration and Reconstruction, and 2Department of Oral Anatomy, Department of Biological Sciences, Niigata University Graduate School of Medical and Dental Sciences, 5274, 2 Ban-cho, Gakkocho-dori, Niigata, 951-8514; 1Department of General Education, Niigata University School of Health Sciences, 2-746, Asahimachi, Niigata, 951-9518, Japan CACorresponding Author Received 12 September 2001; accepted 15 October 2001 Neuroreport: December 21st, 2001 - Volume 12 - Issue 18 - p 3985-3988 Buy SDC Abstract The present study reports on a characteristic spatio-temporal propagation of differential fluorescent images in the rat brain stem slice by a high-speed optical imaging technique. Coronal or sagittal slices were stained with a voltage-sensitive dye RH-414, and the superficial layer of the trigeminal caudalis (Vc) was then electrically stimulated. The marginal layer and substantia gelatinosa showed larger rostrocaudal excitation than coronal, despite a lack of tract stimulation expansion in either direction. A perfusion of 0.5 μmol/l TTX, not 10 μmol/l CNQX suppressed these propagations. These findings suggest that the superficial layer of Vc has spatial differences in neuronal excitation propagation, as evidenced by morphological observations that dendrites in the superficial layers extend in the rostrocaudal direction. © 2001 Lippincott Williams & Wilkins, Inc.