Effect of naloxone on aluminum-induced learning and memory impairment in rats.
BACKGROUND
Uptake of aluminum may disturb the learning and memory of humans or animals. Naloxone (NAL) has been shown to exert beneficial effects on memory deficits.


OBJECTIVE
We investigated the effects of naloxone on aluminum-induced learning and memory impairment in rats.


METHODS
Aluminum-induced learning and memory impairment model was established by gavage of Aluminum chloride (600 mg/kg) for 3 months. Rats were divided into three groups viz. naloxone-treated rats (NAL 0.8 mg/kg, i.p. daily for 7 days), non-treated model rats and normal controls.


METHODS
The Morris water maze test was performed to study spatial learning and memory. Long-term potentiation (LTP) of the Schaffer collateral-CA1 synapse was recorded. Aluminum and zinc contents in the hippocampus were assayed with atomic absorption spectrophotometry.


METHODS
Parameters of the hidden and visible platform trials and data of LTP were analyzed using two-way repeated measures ANOVA.


RESULTS
In the hidden platform trials, escape latencies of the NAL rats were significantly shorter than that of the non-treated rats (P=0.000, 95% confidential interval low bound 14.31, upper bound 22.68). In probe trails, the number of entries in the target area of the NAL rats (6.75+/-1.28 times/min) was more than that of non-treated model rats (4.56+/-2.16 times/min, P=0.004, 95% confidence interval low bound -3.65, upper bound -0.788). The magnitudes of LTP recorded in the CA1 pyramidal neurons of the NAL-treated rats were significantly augmented when compared to the non-treated model rats (P=0.005, 95% confidence interval low bound 0.16, upper bound 0.84).


CONCLUSIONS
NAL could facilitate spatial learning and memory and enhance LTP in the CA1 region of the hippocampus in aluminum-induced learning and memory impairment in rats.
Shi-Lei
Sun
S
Department of Gerontology, First Affiliated Hospital, Zhengzhou University, Zhengzhou-450052, Henan Province, China. replyshilei@hotmail.com
Guang-Yu
M A
MA
Bachelor
Li Hua
LH
Bachelor
Zhu Yun
ZY
Dong
Hong-mei
HM
Xu
Xiao-hu
XH
D000535:Aluminum / Q000633:toxicity*; D000818:Animals; D003072:Cognition Disorders / Q000139:chemically induced* / Q000188:drug therapy*; D005260:Female; D017774:Long-Term Potentiation / Q000187:drug effects; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D009270:Naloxone / Q000494:pharmacology*; D009292:Narcotic Antagonists / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D009292:Narcotic Antagonists; D009270:Naloxone; D000535:Aluminum