In Vitro Study Of Theeffects Of Fullerol On The Hippocampal Synaptic Plastisity

Because of the unique structure and physicochemical properties, fullerene has caught great attention since it was discovered in 1990. In the recent years, fullerene drives extensive application in the research, industry and daily life. The solubility of the fullerene can be improved by chemical modification. And it will extend the application in biological and medical fields. For these reasons, the safety and the potential toxicity of the fullerene and their derivatives should be well studied.The information about the effects of fullerene and their derivatives on senior brain functions is still limited. The learning and memory is one of the most important aspects of these functions. And the synaptic plastisity of the hippocampus plays a key role in the learning and memory. We studied the effects of the polyhydroxylated fullerene (C60(OH)24) on the synaptic plastisity of SC-CA1 path in rat hippocampus. We contrasted the normalized I/O curves, the paired pulse facilitation (PPF) and the long-term potentiation of the fullerol treated group with that of the control group. There is no significant difference on the normalized I/O curves between two groups. The reduction of peak value of PPF in the fullerol treated group is significant, and the paired pulse intervals in which the facilitations reach the peak is different between the two groups. In addition, the value of fEPSP2/fEPSP1 is significant different in the paired pulse interval of 10 ms, 20 ms and 30 ms. The result of the LTP reveals that the potentiation is inhibited by the application of fullerol. These results indicate that fullerol produces negative effects on the synaptic plasitisity in the SC-CA1 path of rat hippocampus.Some fullerene derivatives have inhibitory effect on the activity of nitric oxide synthase. The nitric oxide and NOS play an important role in the formation of the long-term potentiation in the SC-CA1 path of hippocampus. We measured the activity of the NOS in the hippocampus to determine the effect of fullerol. The result indicates that the NOS activity decreased significantly after incubation in the artificial cerebrospinal fluid with fullerol of 5μM for 20 minutes.We measured the content of MDA, activity of SOD and content of GSH in the hippocampus. The content of MDA in the fullerol treated group is significant lower than that of the control group. But there is no significant difference on the activity of SOD and on the content of GSH between two groups. The decrease of the MDA content is due to the scavenging effect on reactive oxide species of the fullerol. And there is no SOD or GSH involved.