Facilitating effect of histamine on spatial memory deficits induced by dizocilpine as evaluated by 8-arm radial maze in SD rats.
OBJECTIVE
To investigate whether or not histamine is involved in spatial memory deficits induced by dizocilpine (MK-801) as evaluated by 8-arm radial maze of rats.


METHODS
8-Arm (4-arm baited) radial maze was used to measure spatial memory in rats.


RESULTS
Bilaterally intrahippocampal (ih) injection of MK-801 (0.3 microg/site) impaired working memory and reference memory in rats. Both histamine (50, 100 ng/site, ih) and intraperitoneal (ip) injection of histidine (100, 200 mg/kg) markedly improved the spatial memory deficits induced by MK-801. On the other hand, the ameliorating effect of histidine (100 mg/kg, ip) was completely antagonized by alpha-fluoromethylhistidine (alpha-FMH, 5 microg/site, ih), a potent and selective histidine decarboxylase (HDC) inhibitor, and H1-antagonist pyrilamine (1 microg/site, ih), but not by H2-antagonist cimetidine, even at a high dose (2.5 microg/site, ih).


CONCLUSIONS
The hippocampal histamine plays an important role in the ameliorating effect on MK-801-induced spatial memory deficits, and its action is mediated through postsynaptic H1-receptor.
Huang
Yu-Wen
YW
Department of Neurobiology and Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310031, China.
Chen
Zhong
Z
Hu
Wei-Wei
WW
Zhang
Li-San
LS
Wu
Wei
W
Ying
Li-Yang
LY
Wei
Er-Qing
EQ
D000818:Animals; D004195:Disease Models, Animal; D016291:Dizocilpine Maleate; D006632:Histamine / Q000494:pharmacology* / Q000627:therapeutic use; D006639:Histidine / Q000494:pharmacology; D007276:Injections, Intraventricular; D008297:Male; D018782:Maze Learning / Q000187:drug effects*; D008569:Memory Disorders / Q000139:chemically induced / Q000188:drug therapy / Q000503:physiopathology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D006639:Histidine; D016291:Dizocilpine Maleate; D006632:Histamine