스트레스에 의한 Long-term potentiation (LTP)의 저하를 감소시키는 리튬의 효과

PURPOSE: The hippocampus is crucially involved in memory formation which has been known to be highly sensitive to stress. Previous studies have been show that exposure to uncontrollable stress is deleterious to hippocampus-dependent memory formation. Recent studies have demonstrated neuroprotective actions of lithium in vivo and in vitro, including prevention of neuronal apoptosis and stress-induced structural remodeling. Enhancement of LTP by lithium treatment was reported by an in vitro study. On the other hand, some studies have reported the attenuation of effects of chronic stress situation. In this study, we investigated whether lithium attenuated or prevented the stress-induced deleterious effects on memory. METHOD: Rats were subjected to a single 1 hour restraint stress and then were immediately sacrificed by decapitation. The brain was dissected and 2 transverse hippocampal slices (400㎛) were prepared for each case. We monitored baseline synaptic transmission for at least 10 minutes and then induced LTP by theta-burst stimulation (TBS) in one slice. Afterward, we treated 0.6mM or 1.0mM of lithium for 20 minutes and monitored baseline synaptic transmission for at least 10 minutes and then, we induced LTP by TBS in the other one. We recorded synaptic responsiveness for every minute during a period of 40 minutes each slice. RESULTS: LTP was significantly induced in the stressed group (M=112.37%, SD=±11.51, p<0.05), in the 0.6mM lithium-treated group (M=141.06%, SD=±8.45, p<0.05), and in the 1.0mM lithium-treated group (M=146.96%, SD=±18.58, p<0.05). Between the stressed group and the 0.6mM lithium-treated group, means of LTP magnitudes were significantly different (p<0.05). Means of LTP magnitudes were also significantly different between the stressed group and the 1.0mM lithium-treated group (p<0.05). But there were no significant differences between the means of LTP magnitudes in the 0.6mM lithium-treated group and the 1.0mM lithium-treated group. CONCLUSION: Lithium can attenuate stress-induced suppression of LTP in the rat hippocampus. This not only supports the current knowledge of neuroprotective effects of lithium, but also shows that lithium may be effective in the treatment of stress-induced impairment of cognitive functions, such as learning and memory. But, from seeing that there is no significant difference between the means of LTP magnitudes in the 0.6mM lithium-treated group and the 1.0mM lithium-treated group, we may suppose that lithium has an ability to attenuate stress-induces suppression of LTP in the rat hippocampus independent from the dosage.

Author dc:creator

• 양, 재진

Contributors dc:contributor

• 정, 영기
• 대학원 의학과
• 200324272

• 리튬
• 스트레스
• 해마
• long-term potentiation (LTP)

Language dc:language

ko

Identifier

http://dcoll.ajou.ac.kr:9080/dcollection/jsp/common/DcLoOrgPer.jsp?sItemId=000000000425
000000000425

OAI identifier oai:identifier

oai:repository.ajou.ac.kr:201003/2331