Aminergic neuron systems of lobsters: morphology and electrophysiology of octopamine-containing neurosecretory cells

In the American lobster (Homarus americanus) the biogenic amines serotonin and octopamine appear to play important and opposite roles in the regulation of aggressive behavior, in the establishment and/or maintenance of dominant and subordinate behavioral states and in the modulation of the associated postural stances and escape responses. The octopamine-containing neurosecretory neurons in the thoracic regions of the lobster ventral nerve cord fall into two morphological subgroups, the root octopamine cells, a classical neurohemal group with release regions along second thoracic roots, and the claw octopamine cells, a group that selectively innervates the claws. Cells of both subgroups have additional sets of endings within neuropil regions of ganglia of the ventral nerve cord. Octopamine neurosecretory neurons generally are silent, but when spontaneously active or when activated, they show large overshooting action potentials with prominent after-hyperpolarizations. Autoinhibition after high-frequency firing, which is also seen in other crustacean neurosecretory cells, is readily apparent in these cells. The cells show no spontaneous synaptic activity, but appear to be excited by a unitary source. Stimulation of lateral or medial giant axons, which excite serotonergic cells yielded no response in octopaminergic neurosecretory cells and no evidence for direct interactions between pairs of octopamine neurons, or between the octopaminergic and the serotonergic sets of neurosecretory neurons was found.     

Indole metabolism in the pineal organ of the pigeon with special reference to melatonin-synthesizing cells

By means of radioimmunoassay a clear-cut peak of melatonin concentration was found in the pineal organ of the pigeon at the middle of the scotophase (Coisin et al. 1982a). The aim of the present study was to identify the cell type responsible for the nocturnal indole metabolism, including melatonin synthesis, in the pineal of this avian species. After a short-term incubation or organ culture in the presence of [3H]-indolic precursors, [3H]-5-hydroxytryptophan or [3H]-5-hydroxytryptamine, the relative amounts of deaminated and acetylated products occurring in the pineal organ were measured by the use of thin layer chromatography and liquid-scintillation counting. It was possible to modify the relative amounts of deaminated and acetylated indoles by the application of some inhibitors of monoamine oxidase and cyclic nucleotide phosphodiesterase. Irrespective of the experimental conditions, high-resolution autoradiography combined with the above-mentioned radiochemical experiments showed that the cells of the receptor line (modified photoreceptor cells) are responsible for indole storage and metabolism, and very probably also for melatonin biosynthesis. The other cell types of the pineal parenchyma did not display significant labeling.     

Hyperthermic treatment of chromomycosis with disposable chemical pocket warmers

A case of chromomycosis in which hyperthermia proved effective is reported. The patient was a 56-year-old male bean curd maker who, without any previous history of minor trauma, developed on the extensor side of the left upper arm an eczematous lesion that underwent gradual radial expansion. The lesion showed a well-defined, 7×10 cm infiltrated erythematous plaque with the central area healed and, at the upper and lower borders, adherent scales and crusts on the surface. Histological examination revealed granulomatous changes in the dermis, as well as sclerotic cells within giant cells and microabscesses. On culturing,Fonsecaea pedrosoi was isolated. The patient was treated with disposable chemical pocket warmers, which were secured over the lesion with a rather tight elastic bandage, so that they kept the affected area warm for 24 hours a day. After a month of such hyperthermic treatment, the erythema and infiltration had decreased considerably, and microscopic examination and culture of the crusts both yielded negative results. Examination of biopsy specimens of the lesion after the third month showed that it had cicatrized. The treatment was stopped after 4 months, and no relapse occurred. We also summarize the published results of local hyperthermic treatment of chromomycosis in Japan.