Table 1.

Results of two-way ANOVA of mRNA

	Anterior hippocampus						Posterior hippocampus
	Age		STIM		Age × STIM		Age		STIM
	F	P	F	P	F	P	F	P	F	P
c-fos	9.41	<0.01	45.25	<0.01	6.16	<0.05	0.03	0.87	0.07	0.81
junB	3.68	0.06	19.45	<0.01	2.26	0.14	0.06	0.82	1.29	0.29
c-jun	3.46	0.07	9.95	<0.01	0.29	0.60	0.18	0.68	2.36	0.16
fosB	1.90	0.17	1.42	0.24	–	–	0.60	0.46	0.00	0.98
fra1	0.41	0.53	1.53	0.22	–	–	0.49	0.50	0.68	0.43
zif268	0.48	0.49	40.13	<0.01	1.53	0.23	–	–	–	–

Separate analyses of mRNA levels from anterior two thirds and posterior one third of hippocampus were performed for the factors AGE (young vs old) and STIM (low frequency vs high frequency). Degrees of freedom for all genes analyzed in anterior hippocampus were (1,32), except for zif268 which was (1,19). In the analysis of posterior mRNA levels, degrees of freedom were (1,9).