Table 1.

BDNF and estradiol interact to produce changes in spine density

Experiment	Control	Estradiol	Treatment groups
1	7.79  ±  0.32	13.78  ±  0.43*	BDNF, 6.33 ± 0.23	BDNF + estradiol, 5.88 ± 0.26
2	8.46  ±  0.43	13.1  ±  0.5*	BDNF, 7.23 ± 0.47	BDNF + k252a, 8.71 ± 0.42
3	8.47  ±  0.38	14.31  ±  0.59*	BDNF, 7.19 ± 0.38	BDNF + k252a, 11.19 ± 0.52*	K252a, 12.7 ± 0.57*
	8.47  ±  0.38	14.31  ±  0.59*	BDNF, 7.19 ± 0.38	BDNF AS,  13.4 ± 0.46*	BDNF RAS, 8.49 ± 0.35
4	9.1  ±  0.29	13.68  ±  0.4*	BDNF, 7.48 ± 0.4	BDNF AS, 14.14 ± 0.45*	BDNF RAS, 8.68 ± 0.49
5	7.62  ±  0.42	11.41  ±  0.8*		Diazepam + estradiol, 7.39 ± 0.34	Diazepam, 6.51 ± 0.4
6	8.59  ±  0.39	13.16  ±  0.06*		BDNF-antibody, 12.18 ± 0.63*

Summary of six experiments measuring <250 dendritic segments from ≈50 cells in each group. Values are spines per 50-μm dendritic segment. Asterisks denote significance from control at P < 0.01 by using unpaired Student’s t test. In experiment 1, note that BDNF by itself causes a 19% reduction in dendritic spine density but totally blocks the effect of estradiol. Experiments 2 and 3 illustrate that both the trk-B receptor antagonist, K252a, and BDNF-AS mimic the effects of estradiol. BDNF by itself does not block the effect of the antagonist, unlike its effect on estradiol, indicating that K252a acts downstream of BDNF. In experiment 5, diazepam blocks the effects of estradiol on spine density, indicating that the GABAergic link is important in regulating spine formation. Finally, in experiment 6, BDNF-Ab mimics the effects of estradiol.