Diana G, Scotti de Carolis A, Frank C, Domenici M R, Sagratella S
Pharmacology Department, Istituto Superiore di Sanità, Roma, Italy.
Brain Res Bull. 1994;35(2):107-11. doi: 10.1016/0361-9230(94)90089-2.
Induction of posttetanic potentiation (PTP) and long-term potentiation (LTP) was analyzed in hippocampal slices obtained from a) young 6-month-old Sprague-Dawley (SD) rats, all of them performing well in the Morris Maze, and b) aged SD 20-month-old and Fischer 344 24-month-old rats showing different degrees of ability in the same test. After the application of an electrical tetanus 1 s, 100 Hz, 50 microA in the stratum radiatum, no significant differences were found in the percent of induction of both PTP and LTP in the CA1 area of hippocampal slices obtained from rats of different strains and ages. After the application of an electrical tetanus 1 s, 100 Hz, 50 microA in the stratum moleculare, a significant difference was found in the percent of dentate PTP induction in hippocampal slices obtained from rats of different ages. Specifically, dentate PTP induction was significantly (p < 0.01) higher in slices obtained from young SD rats, and from old SD rats with a better performance in the Morris maze, escape latency less than 10 s and 150 cm, than in slices obtained from old SD or Fischer 344 rats that had shown poor performance in the Morris Maze. On the contrary, no significant differences were found in the percent of dentate LTP in hippocampal slices obtained from rats of different strains and ages. The data demonstrate that the induction of hippocampal dentate high-frequency PTP is selectively reduced in old rats with impaired Morris Maze performance.
在从以下大鼠获取的海马切片中分析强直后增强（PTP）和长时程增强（LTP）的诱导情况：a）6个月大的年轻斯普拉格-道利（SD）大鼠，它们在莫里斯水迷宫中表现良好；b）20个月大的老年SD大鼠和24个月大的费希尔344大鼠，它们在同一测试中表现出不同程度的能力。在海马辐射层施加1秒、100赫兹、50微安的电强直刺激后，在从不同品系和年龄的大鼠获取的海马切片CA1区中，PTP和LTP的诱导百分比未发现显著差异。在分子层施加1秒、100赫兹、50微安的电强直刺激后，在从不同年龄的大鼠获取的海马切片齿状回PTP诱导百分比中发现显著差异。具体而言，从年轻SD大鼠以及在莫里斯水迷宫中表现较好（逃避潜伏期小于10秒且路径长度小于150厘米）的老年SD大鼠获取的切片中，齿状回PTP诱导显著（p<0.01）高于从在莫里斯水迷宫中表现较差的老年SD大鼠或费希尔344大鼠获取的切片。相反，在从不同品系和年龄的大鼠获取的海马切片齿状回LTP百分比中未发现显著差异。数据表明，在莫里斯水迷宫表现受损的老年大鼠中，海马齿状回高频PTP的诱导选择性降低。
