... part dark. We moved the horizon so that its elevation changed in a sinusoidal way, and we made intracellular recordings separately from L-neurons and from the cell body of the DNI ( Fig. 6A ). As expected, an upward movement of the horizon (decreasing the light on the ocellus) depolarized L-neurons...

.... Two pigmented structures in the brain of the ascidian larva, the ocellus and the otolith, have been shown to function as the photoreceptive and gravity sensitive organs, respectively. Here, we show that pigmentation is essential for proper phototactic and geotactic behavior in larvae of the ascidian...

... is an otolith, presumably used for gravity detection,and the posterior pigment cell is an ocellus, used for photoreception. However, there is no direct experimental evidence for this assignment of function. Upward swimming behaviour occurring during the initial period of larval life was examined before...

..., the pigmentation appears to be required for positive phototaxis, and the results provide further support for the shadowing role of ocellar haemoglobin. * e-mail: [email protected] 11 2 2000 23 4 2000 © 2000 by Company of Biologists 2000 ocellus phototaxis orientation mechanism...

... the same reversal potential as hyperpolarizing potentials evoked by photoreceptor illumi-nation. When applied ionophoretically in the ocellus, other biogenic amines, including octopamine, dopamine and noradrenaline, had no effect on the L-neurones. Both gamma-aminobutyric acid and acetylcholine, however...

...Takahiro Ohyama; Yoshihiro Toh ABSTRACT Many insects possess two or three dorsal ocelli in addition to the paired compound eyes. The dorsal ocellus is characterized by a high convergent ratio of many retinular axons upon several thick second-order neurones in the posterior region of the ocellus...

... of Biologists 1985 Postsynaptic potential spike ocellus Schistocerca Large, second-order neurones of locust ocelli (‘L-neurones’) provide useful subjects for investigations on the transmission of signals both within a single neurone, and across synapses between neurones. Pairs...