Nervous system of Periplaneta americana cockroach is used in a wide range of pharmacological studies, including electrophysiological techniques. This paper presents its role as a preparation in the development of toxinological studies in the following electrophysiological methods: double-oil-gap technique on isolated giant axon, patch-clamp on DUM (dorsal unpaired median) neurons, microelectrod...

A number of recent studies have investigated posterior development in several different arthropods. As previously found in spiders, it has been discovered that Delta-Notch signaling is required for the development of posterior segments in an insect, the cockroach Periplaneta americana. Furthermore analysis of Wnt8 function in the spider Achaearanea tepidariorum and the beetle Tribolium castaneu...

In Brazil, synanthropic cockroaches are considered one of the insect groups greatest economic importance. Aprostocetus hagenowii (Ratzeburg, 1852) (Hymenoptera: Eulophidae) and Evania appendigaster (Linnaeus, 1758) Evaniidae) parasitoid species that natural enemies Periplaneta americana (Blattaria: Blattidae) can be adopted in biological control. Here we point out occurrence A. parasitizing P. ...

Individual giant interneurons (GIs) in the ventral nerve cord of the cockroach, Periplaneta americana, were lesioned by intracellular injection of proteolytic enzymes (pronase). This was accomplished with minimal dissection, so that the wind-evoked escape behavior of the animals could be studied following the lesion. Unilateral lesions of GI-2 had no obvious effect on escape behavior, but unila...

Abstrac t -1 . Three fluorescing materials have been discovered in excreta from the American cockroach, Periplaneta americana (L.), and found to increase in concentration as dietary nitrogen increases. 2. These compounds have been identified as kynurenic, xanthurenic and 8-hydroxyquinaldic acids. 3. Feeding cockroaches antibiotic eliminates 8-hydroxyquinaldic acid production, presumably by inhi...

The distribution of microtubules and mitochondria in central axons of an insect (Periplaneta americana) is assessed by comparison between counts on micrographs and computed axon random 'models'. These studies show that the observed multiple association of microtubules with individual mitochondria is statistically highly significant. Electron micrographs of thin sections show that linkage is eff...

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. The thick second-order neurones extend towards the brain as an ocellar nerve together with other thin processes, and their central projectio...

Nine tachykinin-related peptides (TRPs) have been isolated from the brain and intestine of the cockroach Leucophaea maderae. In the present investigation, two of the nine TRPs, LemTRP 1 and 5, were tested for their ability to stimulate contractions in the foregut of the cockroaches L. maderae and Periplaneta americana in vitro. The two LemTRPs and the related locust peptide locustatachykinin I ...