Effects of postweaning chronic aluminum exposure on LTP and expression of PKA in hippocampus of rats

Abstract

Objective To study the change of LTP and the experssion of PKA in hippocampus of rats after postweaning chronic aluminum exposure of different concentration,and to go deep into the synaptic mechanism of that aluminum impairs learning and memory capacity. Methods The extracelluar microelectrode technique was used to monitor the LTP. The expression of PKA in hippocampus was measured by the method of western-blot. Results The occurrence of LTP in control group was 78.78%,in 0.2%-Al group was 60%,and in 0.4%-Al group was 44.44%.Moreover,the PS mean amplitudes relative to the baseline values after HFS in control group was(144.69±29.91)%,in 0.2%-Al group was(113.57±16.47)%,and in 0.4%-Al group was (103.91±19.96)%;compared with the control group,in 0.4%-Al group,the PS mean amplitudes relative to the baseline values were significantly decreased( P =0.033).The content of PKA in control group was 1.45±0.36,in 0.2%-Al group was 1.02±0.22,and in 0.4%-Al group was 0.72±0.12;compared to the control group,the expression of PKA in hippocampus was significantly reduced in two Al3+ exposed groups ( P =0.000),and the difference between the two exposed groups was statistically significant ( P =0.000). Conclusion Postweaning aluminum exposure can damage the expression of LTP in hippocampus of rats,consquentely impair the ability of learning and memory,which might be related to the decrease of the expression of PKA in the hippocampus. Key words: Aluminum exposure; LTP; PKA; Weaning