The activation of heteromeric and homomeric nicotinic acetylcholine receptors was studied in Xenopus laevis oocytes to identify key structures of putative agonist molecules associated with the selective activation of homomeric 7 receptors. We observed that selectivity between 7 and 4 2 was more readily obtained than selectivity between 7 and 3 4. Based on structural comparisons of previously ch...

Six commonly freshwater ornamental fish, namely Poecilia rediculata (guppy); Poecilia sphenops (black molly); Cichlosoma sp. (Cichlidae); Xiphophorus maculatus (platy); Carassius auratus (goldfish) and Symphisodon discus (discus) were examined for parasites during a four years study (19982002) in Turkey. The parasites species found included: Ichthyobodo sp., Ichthyophthirius multifiliis, Chilod...

—Amphibians that breed in early spring may encounter considerable variation in ambient temperature. In this study, I investigated how the metabolic rate of male and female Small-Mouthed Salamanders (Ambystoma texanum) is influenced by variation in temperature (5–208C) during the reproductive season. As expected, both rates of resting oxygen consumption (VO2) and resting carbon dioxide productio...

Secondary cartilage forms on avian and mammalian dermal bones, both during normal ontogeny and during repair of fractures, but it has not been observed in any other vertebrate class. We fractured the left lower jaws of adult spotted salamanders, Ambystoma maculatum, to see whether secondary cartilage would form during fracture repair. It did not. Instead, periosteal hyperplasia produced a callu...

N,N -Dicyclopentyl-2-methylsulfanyl-5-nitro-pyrimidine-4,6diamine (GS39783) and structurally related compounds are described as novel allosteric enhancers of GABAB receptor function. They potentiate GABA-stimulated guanosine 5 -O-(3-[S]thio)triphosphate ([S]GTP S) binding to membranes from a GABAB(1b/2)-expressing Chinese hamster ovary cell line at low micromolar concentrations, but do not stim...

Dopamine is a key neuromodulator of locomotory circuits, yet, the role that dopamine plays during development of these circuits is less well understood. Here, we describe a suppressive effect of dopamine on swim circuits in larval zebrafish. Zebrafish larvae exhibit marked changes in swimming behavior between 3 days post fertilization (dpf) and 5dpf. We found that swim episodes were fewer and o...

A batch of experimental rainbow trout was found to have a high level of spinal deformities. An equal deformity level was found in fish from the same batch, but reared at the fish farm from where the fry originated, suggesting that the all-female triploid status of the rainbow trout might account for the high level of deformity. Many factors being of physical, chemical, environmental or genetic ...