Increase in p-Elk-1 after the induction of LTP.a, Immunocytochemical images in the ipsilateral dentate gyrus shows an increase in p-Elk-1 at LTP 0 and to a lesser extent at LTP 15 compared with the contralateral side. No change was observed in the control groups. b, High magnification (630×) of these images shows p-Elk-1 labeling in both cell bodies and dendrites in the ipsilateral dentate gyrus. c, Densitometric quantification of immunolabeling shows that p-Elk-1 is significantly increased at LTP 0 and LTP 15. d, Western blots of p-Elk-1 confirm immunohistochemical results showing increased p-Elk-1 at LTP 0 (top panel), and this increase was only observed with the activated form, with no change in total Elk-1 (bottom panel).