Long-term analysis of ltp in the hippocampal acute slice of mouse using multielectrode array recording.
C. Bessho, H. Hoshino, T. Enomoto.
Society for Neuroscience, 56.12. (2004)
Dept Physics, Kyoto Sangyo Univ, Kyoto, Japan
Long-term potentiation (LTP) in the hippocampus is considered to be a fundamental mechanism of memory process. It consists of two phases: early LTP, lasting minutes or several hours and late LTP, lasting longer than 4 h. The late LTP is dependent on synthesis of mRNA and proteins. Multielectrode array system has provided a powerful means for monitoring neural electrical activity of brain neural circuits non-invasively and simultaneously. In order to study the late LTP , we applied multielectrode array system to hippocampal acute slices of a 4-week-old ICR mouse. The thickness of each slice was 300 m. Each slice was soaked in the oxygenated preparation buffer for 1 h at 32 C. Then a slice was placed on the multielectrode dish (MED) probe and the MED probe and connector were placed in a CO2 incubator at 34 C. The medium was replaced with the oxygenated recording buffer. A single pair of planar microelectrodes of the 64 available was used for stimulating. Schaffer collateral axons were stimulated by a pair of microelectrodes with biphasic constant current pulses (amplitude, 40 A, duration, 100 s). LTP was induced by theta burst conditioning stimulation which is four-pulse, 100 Hz bursts repeated ten times at 200 ms intervals. We re-evaluated the effects of a protein synthesis inhibitor, anisomycin, on LTP. Anisomycin was applied to the recording solution 30 min before theta burst until the end of the experiment. LTP in the CA1 region could be monitored for a long-term period (6.5h). In the presence of anisomycin (25 M), the potentiation of the EPSP gradually decreased to the basal level.
