Spatial memory impairment induced by tooth-loss and scopolamine
Objective: Extracting of the teeth impairs acquisition of spatial memory implying the possible alteration of the neural networks in the brain caused by a reduction of mastication. Systemic infusion of the messianic cholinergic receptor antagonist scopolamine produces an amnesic syndrome in human and rodents. Morris water maze experiment was performed to examine the effect of tooth-loss and scopolamine on learning and memory.Methods: Wister male rats of 8 weeks were divided into 3 groups. Upper bilateral molars were extracted, and ridges were allowed to heal for 3 weeks. Scopolamine (1mg/kg) was injected for 1 week before training tasks. In the acquisition phase, each rat received 2 sessions per day for five consecutive days, each session consisting of four trials. On each task, the time taken to reach the submerged platform (escape latency) was measured. The acquisition phase was followed by the probe trial, in which the platform was present at 1h, 1, 2, 4, 7days after acquisition phase. The rats were allowed to swim freely for 60 second, and the total time that the subjects spent in each quadrant of the tank was recorded. Data were analyzed using ANOVA.Results: Average escape latency in all groups decreased progressively with increased training, but scopolamine treated and tooth extracted groups showed longer escape latency than control group (P<.05). At the end of the training, all rats spent most of the time swimming in the quadrant where the platform had been placed during the trial phase. The time spent in the training quadrant by the tooth extracted group was significantly lower than the time spent by the control group (P<.05).Conclusion: Although scopolamine affected only memory, tooth-loss affected both learning and memory.
Division: Japanese Division Meeting
Meeting:2004 Japanese Division Meeting (Tokyo, Japan) Location: Tokyo, Japan
Year: 2004 Final Presentation ID:26 Abstract Category|Abstract Category(s):Scientific Groups
Authors
Hara, Tetsuya
( Okayama University, Okayama City, N/A, Japan
)
Shimazu, Chie
( Okayama University, Okayama City, N/A, Japan
)
Hanada, Shunshi
( Okayama University, Okayama City, N/A, Japan
)
Kinuta, Yoshihiro
( Okayama University, Okayama City, N/A, Japan
)
Minagi, Shogo
( Okayama University, Okayama City, N/A, Japan
)