Figure 4From: Seasonal changes in expression of nerve growth factor and its receptors TrkA and p75 in the ovary of wild ground squirrel (Citellus dauricus Brandt)Seasonal change of the plasma concentration of LH, FSH, estradiol-17β and progesterone. Plasma LH (a), FSH (b), estradiol-17β (c), and progesterone (d) levels in the wild ground squirrel during breeding period (B) and nonbreeding period (NB). Bars represent means + SD for five independent experiments. Means within the columns marked with different letters indicate significant difference (P < 0.01).Back to article page