Fig. 5. Effects of serotonin on the spontaneous activity recorded from the
separated proximal optic stalk. (A) Application of serotonin into the optic
lobe suppressed the spontaneous activity in a dose-dependent manner during
both day (open squares) and night (filled squares). a and b indicate a
significant difference (P<0.05, t-test) compared with the
Ringer-injected control for day and night, respectively. Values are means
± S.E.M. of 5-8 preparations. (B) Serotonin (10 pmol) injected into the
optic lobe significantly suppressed the spontaneous firing rate, which was
further reduced when the contralateral optic stalk was severed. When the
contralateral optic lobe was removed, the spontaneous activity was
significantly reduced, and this value was increased only slightly when
serotonin was injected into the protocerebral lobe after the removal of the
optic lobe. Values are means ± S.E.M. of 5 preparations, given as
percentage of the value before treatments (untreated).
*P<0.01, t-test.
