Two Methods for Serial Sectioning of Arthropods and Insects

Histopathology of Nomuraea rileyi in larvae of Heliothis zea and in vitro enzymatic activity

Adult and nymphal antennae of the cockroach, Leucophaea maderae, contain nine or more different morphological types of sense organs. There is no outwardly apparent sexual dimorphism in adult antennae. Nymphs are dificient in gross numbers of sensilla. Sense organs are classified morphologically by their similarity to known types of sensila and are assigned functions on this basis and preliminary electrophysiological data: Sensilla chaetica (A), thick-walled mechanoreceptive hairs in groups on the antennal base; S. chaetica (B), thick-walled setae which are tactile and probably chemoreceptive, occurring in the antennal base and flagellum; S. trichodea (A), thin-walled chemoreceptive hairs of the flagellum; S. trichodea (B), minute hairs on the scape and pedicel; S. basiconica, thin-walled chemoreceptive pegs, and S. coeloconica („pit-pegs”) of the flagellum; S. campaniformia and scolopidia, mechanoreceptors in the base and flagellum; plus Johnston's organ and/or connective chrodotonal organs in the pedicel. Calculations based on absolute counts of sensilla and their known innervation yield an estimate of about 3.3 × 104 sensilla and 105 cells per antenna.

Antennal sense organs of the cockroach, Leucophaea maderae.

Parkinson's disease (PD) affects >1 million Americans and is marked by the loss of dopaminergic neurons in the substantia nigra. PD has been linked to two causative factors: genetic risks (hereditary PD) and environmental toxins (idiopathic PD). In recent years, considerable effort has been devoted to the development of a Drosophila model of human PD that might be useful for examining the cellular mechanisms of PD pathology by genetic screening. In 2000, Feany and Bender reported a Drosophila model of PD in which transgenic flies expressing human mutant alpha-synuclein exhibited shortened life spans, dopaminergic losses, Parkinsonian behaviors, and Lewy bodies in surviving dopaminergic neurons. Since then, a number of studies have been published that validate the model or build on it; conversely, a number report an inability to replicate the results and suggest that most protocols for dopaminergic histology underreport the actual numbers of dopaminergic neurons in the insect brain. Here we report the optimization of dopaminergic histology in Drosophila and identification of new dopaminergic neurons, show the remarkable dendritic complexity of these neurons, and provide an updated count of these neurons in adult brains. This manuscript contains online supplemental material at http://www.jhc.org. Please visit this article online to view these materials.

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https://journals.sagepub.com/doi/pdf/10.1369/jhc.2008.951137

An Optimized Method for Histological Detection of Dopaminergic Neurons in Drosophila melanogaster

A saurian hemogregarine, Hepatozoon sauromali sp. n., is described from the chuckwalla Sauromalus spp. collected in Baja California, Mexico, and California. Gametocytes develop in the erythrocytes and schizogony takes place in the liver. The number of merozoites in the mature schizont averages 24. The vector of the parasite is a new species of mite of the genus Hirstiella. Transmission is by the oral route. Sporogony takes place in the mite's body cavity. The large oocysts contain sporocysts, each of which has approximately 12 sporozoites. Mites which had been permitted to engorge on parasitized chuckwallas were fed to "clean" Sceloporus lizards. These showed blood cell infections 30 days later. The name "hemogregarine" is in common usage for a number of organisms belonging to different genera; some of these organisms have been arbitrarily placed in a genus solely on the morphology of the parasite in the blood of the vertebrate host. Although hemogregarines have been reported from a number of saurian hosts, in the majority of instances only the forms in the peripheral blood have been

Hepatozoon sauromali sp. n., a Hemogregarine from the Chuckwalla (Sauromalus spp.) with Notes on the Life History

A method of tissue embedding using n-butyl methacrylate and paraffin is described. Following alcohol dehydration and infiltration with the methacrylate monomer, tissues are embedded in gelatin capsules in a mixture consisting of 3.5 g of paraffin for each 10 ml of methacrylate. Benzoyl peroxide (0.2 g for each 10 ml of monomer) is added as the catalyst and the methacrylate polymerized in a 50 C oven for 18-24 h. Following polymerization the block is trimmed and embedded in paraffin to provide a firm support during sectioning. A water trough attached to the microtome knife is essential to facilitate the handling of sections and ribbons. For serial sections a mixture of equal weights of beeswax and paraffin is used to make the sections adhere to each other. Usual staining procedures can be used since the embedding medium is readily soluble in xylene.

Two Methods for Serial Sectioning of Arthropods and Insects

Citations

Histopathology of Nomuraea rileyi in larvae of Heliothis zea and in vitro enzymatic activity

Antennal sense organs of the cockroach, Leucophaea maderae.

An Optimized Method for Histological Detection of Dopaminergic Neurons in Drosophila melanogaster

Hepatozoon sauromali sp. n., a Hemogregarine from the Chuckwalla (Sauromalus spp.) with Notes on the Life History

N-Butyl methacrylate and paraffin as an embedding medium for light microscopy.