Enhancement of rat hippocampal long-term potentiation by 17 beta-estradiol involves mitogen-activated protein kinase-dependent and -independent components.
To investigate if estrogen modulates long-term potentiation (LTP) via mitogen-activated protein kinase (MAPK) activation, in vitro hippocampal slices were used to induce LTP through extracellular field recordings. Slices perfused with 17beta-estradiol exhibited a significant enhancement of LTP (224+/-19%) compared with LTP in control slices (157+/-9%). In the presence of PD098059, 17beta-estradiol still produced a significant magnitude of LTP (131+/-7%), revealing the existence of p-MAPK-independent LTP mediated by 17beta-estradiol. Immunocytochemistry showed that 17beta-estradiol promoted a transient increase in nuclear translocation of p-MAPK. 17beta-estradiol induced the extracellular proteolysis of neural cell adhesion molecule in a p-MAPK-independent manner, indicating that 17beta-estradiol may act on synaptic remodeling. These results indicate that 17beta-estradiol might affect hippocampal synaptic plasticity in a way involving two separate pathways, which are MAPK-dependent and MAPK-independent.
Kim
Jin Seuk
JS
Department of Biochemistry, Hanyang University College of Medicine, 17 Haengdang-dong, Sungdong-gu, Seoul 133-791, South Korea.
Kim
Hye Young
HY
Kim
Jin Hyuk
JH
Shin
Hong Kee
HK
Lee
Sang Hun
SH
Lee
Yong Sung
YS
Son
Hyeon
H
D000818:Animals; D004958:Estradiol / Q000494:pharmacology*; D006624:Hippocampus / Q000187:drug effects* / Q000201:enzymology*; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000187:drug effects* / Q000502:physiology; D008297:Male; D020928:Mitogen-Activated Protein Kinases / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D004958:Estradiol; D020928:Mitogen-Activated Protein Kinases