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. 1997 Nov 15;17(22):8909–8918. doi: 10.1523/JNEUROSCI.17-22-08909.1997

Fig. 8.

Fig. 8.

The change in LH (ng/ml ± SEM) and in the number of activated cells within the infundibular complex measured 30 hr after dawn in castrated quail after exposure to various photoperiods, illustrating the relationship between these two events after photophase extension. Birds were sampled after 6 (n = 5), 10 (n = 6), 12 (n = 6), 14 (n = 6), 16 (n = 6), 18 (n = 6), 20 (n = 5), or 24 (n = 5) hr of light. As the photophase lengthens, there is a significant increase in the change in LH [one-factor ANOVA; F(7,37)= 3.36; p < 0.01]. The change is significant at hour 30 after photophases as short as 14 hr (3.0 ± 1.39 ng/ml;n = 6; *p < 0.05). Numbers of FLI (mean ± SEM) also increased significantly with an increase in photophase [one-factor ANOVA; F(7,37) = 9.65; ***p < 0.001]. The number of FLI cells is first significant at hour 30 after a photophase of 16 hr (13.6 ± 3.5; n = 6).