Synchronization of wing beat cycle of the desert locust, Schistocerca gregaria, by periodic light flashes.

Studies on the generation of rhythmic motor patterns have shown that peripheral sensory input may contribute substantially to the rhythm generating network. A prominent example is the wing beat frequency of desert locusts, which can be entrained to rhythmic mechanosensory input, but also to the frequency of periodic light flashes. To further analyze the entrainment by light, tethered flying locusts were presented with periodic light flashes, while the position of the forewing was filmed.

Applicability of white-noise techniques to analyzing motion responses.

Motion processing in visual neurons is often understood in terms of how they integrate light stimuli in space and time. These integrative properties, known as the spatiotemporal receptive fields (STRFs), are sometimes obtained using white-noise techniques where a continuous random contrast sequence is delivered to each spatial location within the cell's field of view. In contrast, motion stimuli such as moving bars are usually presented intermittently.

Curiosity and context revisited: crassulacean acid metabolism in the Anthropocene.

Having gained some understanding of the consequences of the CO(2)-concentrating mechanisms in crassulacean acid metabolism (CAM) that internalize the photosynthetic environment of the Cretaceous on a daily basis, it may be time to consider potential long-term effects of the planetary CO(2)-concentrating mechanism on growth and ecology of these plants in the Anthropocene. This paper emphasizes our limited understanding of the carbohydrate economy of CAM in relation to growth processes and briefly reviews recent studies of the diel cycles of growth in these plants. An inadvertent long-term, regional-scale experiment from the past is revisited in which an Opuntia monoculture grew to occupy >25 million hectares of farmland in central eastern Australia, producing a total biomass of about 1.

Directional selectivity in the simple eye of an insect.

Among other sensory modalities, flight stabilization in insects is performed with the aid of visual feedback from three simple eyes (ocelli). It is thought that each ocellus acts as a single wide-field sensor that detects changes in light intensity. We challenge this notion by providing evidence that, when light-adapted, the large retinal L-neurons in the median ocellus of the dragonfly respond in a directional way to upward moving bars and gratings.

Form vision in the insect dorsal ocelli: an anatomical and optical analysis of the dragonfly median ocellus.

Previous work has suggested that dragonfly ocelli are specifically adapted to resolve horizontally extended features of the world, such as the horizon. We investigate the optical and anatomical properties of the median ocellus of Hemicordulia tau and Aeshna mixta to determine the extent to which the findings support this conclusion. Dragonfly median ocelli are shown to possess a number of remarkable properties: astigmatism arising from the elliptical shape of the lens is cancelled by the bilobed shape of the inner lens surface, interference microscopy reveals complex gradients of refractive index within the lens, the morphology of the retina results in zones of high acuity, and the eye has an exceedingly high sensitivity for a diurnal terrestrial invertebrate.

Form vision in the insect dorsal ocelli: an anatomical and optical analysis of the Locust Ocelli.

The dorsal ocelli are commonly considered to be incapable of form vision, primarily due to underfocused dioptrics. We investigate the extent to which this is true of the ocelli of the locust Locusta migratoria. Locust ocelli contain thick lenses with a pronounced concavity on the inner surface, and a deep clear zone separating retina and lens.

The mapping of visual space by dragonfly lateral ocelli.

We study the extent to which the lateral ocelli of dragonflies are able to resolve and map spatial information, following the recent finding that the median ocellus is adapted for spatial resolution around the horizon. Physiological optics are investigated by the hanging-drop technique and related to morphology as determined by sectioning and three-dimensional reconstruction. L-neuron morphology and physiology are investigated by intracellular electrophysiology, white noise analysis and iontophoretic dye injection.

The mapping of visual space by identified large second-order neurons in the dragonfly median ocellus.

In adult dragonflies, the compound eyes are augmented by three simple eyes known as the dorsal ocelli. The outputs of ocellar photoreceptors converge on relatively few second-order neurons with large axonal diameters (L-neurons). We determine L-neuron morphology by iontophoretic dye injection combined with three-dimensional reconstructions.

A spatiotemporal white noise analysis of photoreceptor responses to UV and green light in the dragonfly median ocellus.

Adult dragonflies augment their compound eyes with three simple eyes known as the dorsal ocelli. While the ocellar system is known to mediate stabilizing head reflexes during flight, the ability of the ocellar retina to dynamically resolve the environment is unknown. For the first time, we directly measured the angular sensitivities of the photoreceptors of the dragonfly median (middle) ocellus.

Volatile organic compounds as signals in a plant-herbivore system: electrophysiological responses in olfactory sensilla of the moth Cactoblastis cactorum.

The morphological sensillum types on the antennae of male and female Cactoblastis cactorum were visualized by scanning electron microscopy. Electrophysiological recordings were performed for the first time on single olfactory sensilla of C. cactorum.

The renal type IIa Na/Pi cotransporter: structure-function relationships.

The type IIa Na/Pi cotransporter mediates proximal tubular brush-border membrane secondary active phosphate (Pi) flux. It is rate limiting in tubular Pi reabsorption and, thus, a final target in many physiological and pathophysiological situations of altered renal Pi handling. In the present short review, we will briefly summarize our current knowledge about the transport mechanism (cycle) as well as particular regions of the transporter protein ("molecular domains") that potentially determine transport characteristics.

Effects of changes in atmospheric carbon dioxide on the location of hosts by the moth, Cactoblastis cactorum.

Sensory organs that detect CO are common in herbivorous moths and butterflies, but their function has been unclear until now. As the CO gradients in the vicinity of a host plant depend on its physiological condition, CO could provide a sensory cue for the suitability of the plant as a larval food source. This study investigated whether changing the atmospheric CO concentration affected oviposition by Cactoblastis cactorum on its host, the cactus Opuntia stricta.