TY - JOUR
T1 - Marked increase in [3H](R) α-methylhistamine binding in the superior colliculus of visually deprived rats after unilateral enucleation
AU - Nakagawa, Yoichi
AU - Yanai, Kazuhiko
AU - Ryun, Jong Hoon
AU - Kiyosawa, Motohiro
AU - Tamai, Makoto
AU - Watanabe, Takehiko
N1 - Funding Information:
This study was partly supported by Grants from the Ministry of Education, Science and Culture (# 05770057) of Japan, the Ministry of Health and Welfare (# 3SI-5, # 3Kou-6) of Japan, the Japanese Research Foundation for Clinical Pharmacology and the Japanese Foundation for Neuroscience and Mental Health.
PY - 1994/4/18
Y1 - 1994/4/18
N2 - The binding of [3H](R)α-methylhistamine to histamine H3-receptors in visual structures of unilaterally enucleated rats was examined by quantitative autoradiography to clarify the involvement of histamine neurons in the visual system. [3H](R)α-Methylhistamine binding in the visually deprived superior colliculus, contralateral to the enucleated eye, was significantly increased 5, 15, 30 and 45 days after unilateral enucleation. Slight time-dependent increases in ligand binding were observed in the visual cortex, but the change was significant only 45 days after unilateral enucleation. Unilateral enucleation had no significant effect in the dorsal lateral geniculate nucleus at any time after enucleation. Continuous injection of (S)-α-fluoromethylhistidine, a specific inhibitor of l-histidine decar{ballot box}ylase, attenuated the effect of unilateral enucleation in the superior colliculus. These results suggest that retinal deafferentation induced an increase in histamine H3-receptor binding sites, probably by selective adjustment of histamine neurons in response to unilateral enucleation.
AB - The binding of [3H](R)α-methylhistamine to histamine H3-receptors in visual structures of unilaterally enucleated rats was examined by quantitative autoradiography to clarify the involvement of histamine neurons in the visual system. [3H](R)α-Methylhistamine binding in the visually deprived superior colliculus, contralateral to the enucleated eye, was significantly increased 5, 15, 30 and 45 days after unilateral enucleation. Slight time-dependent increases in ligand binding were observed in the visual cortex, but the change was significant only 45 days after unilateral enucleation. Unilateral enucleation had no significant effect in the dorsal lateral geniculate nucleus at any time after enucleation. Continuous injection of (S)-α-fluoromethylhistidine, a specific inhibitor of l-histidine decar{ballot box}ylase, attenuated the effect of unilateral enucleation in the superior colliculus. These results suggest that retinal deafferentation induced an increase in histamine H3-receptor binding sites, probably by selective adjustment of histamine neurons in response to unilateral enucleation.
KW - Histamine H-receptor
KW - Neuronal plasticity
KW - Receptor autoradiography
KW - Superior colliculus
KW - Unilateral enucleation
KW - Visual system
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U2 - 10.1016/0006-8993(94)90010-8
DO - 10.1016/0006-8993(94)90010-8
M3 - Article
C2 - 8032934
AN - SCOPUS:0028178470
VL - 643
SP - 74
EP - 80
JO - Molecular Brain Research
JF - Molecular Brain Research
SN - 0006-8993
IS - 1-2
ER -