Abstract: Immunohistochemical technique was used in the present study to detect and compare Jun expressed in HV and LPO of the chick ' s two hemispheres following monovisual deprivation and one-trial passive avoidance task. It was shown that monovisual deprived 2 hours, 24 hours, 48 hours or 72 hours induced Jun expression definitely increased in HV and LPO of the two hemispheres, and Jun expression came to the highest level when visually deprived 48 hours; the expression in the left LPO was higher than that in the right LPO after being visually deprived 2 hours; monovisually deprived 2 hours and 24 hours following one-trail passive avoidance task and memory retention test at 70 minute after learning induced Jun expression to continue increase in HV and LPO of the two hemispheres; monovisually deprived 2 hours test at 10 minute just induced Jun expression obvious increase in the left LPO and HV; only the left LPO showed high level Jun expression after monovisually deprived 24 hours and test at 10 minutes; in the same hemisphere, the fact that the Jun expression of LPO was higher than that in HV disappeared after being visually deprived 48 hours.

Key words: chick, Jun-like protein, Immunohistochemical, hemisphere, HV, LPO one-trail passive avoidance task