RESUMEN
AIM: To investigate the effect of chronic lead exposure on rat hippocampal CA1 LTP and alpha-Ca2+ /calmodulin-dependent protein kinase II (alpha-CaM K II) activity in vivo. METHODS: A stimulus bipolar electrode was placed on the Schaffer/Commissural fibers, with extra cellular microelectrode technique to record the population spike (PS) in the CA1 pyramidal, and we observed the changes of PS amplitude before and after the high frequency stimulation (HFS) of lower, mid and higher level lead exposure groups and the control group, respectively. The hippocampal CA1 alpha-CaM K II activity was determined by Western blots by using phosphorylation antibody. RESULTS: The average changes of PS after HFS of the control group, the lower, mid and higher level lead exposure groups were 162.5%, 105.2%, 86.8%, 83.0%, respectively (P < 0.01 vs. control). Defined control a-CaM K II activity as 100, that the lower, mid and higher level lead exposure groups were 62.0 +/- 3.7, 50.8 +/- 4.0, 43.3 +/- 4.1 (P < 0.01). CONCLUSION: Chronic lead exposure can inhibit CA1 LTP in vivo, and the decrease of alpha-CaMK II activity may play an important role in this mechanism.