Evidence of histamine receptors in fish brain using an in vivo [14C]2-deoxyglucose autoradiographic method and an in vitro receptor-binding autoradiographic method.

It was hypothesized that fish possess functioning H1 histamine receptors that have the ability to bind agonists and antagonists specific to the H1 histamine receptor subtype. For these experiments, a combination of a novel, in vivo 2-deoxyglucose method and a standard in vitro autoradiography procedure was utilized. A regional, statistically significant dose response in neurological functioning was observed when fish were exposed to histaminergic agents (i.

Design, synthesis and pharmacological profile of novel dopamine D2 receptor ligands.

The present study describes the synthesis and pharmacological profile of three novel heterocyclic compounds originally designed, on the basis of bioisosterism, as dopamine D2 receptor ligands: 1-[1-(4-chlorophenyl)-1H-pyrazol-4-ylmethyl]-4-phenyl-piperazine (LASSBio-579), 1-phenyl-4-(1-phenyl-1H-[1,2,3]triazol-4-ylmethyl)-piperazine (LASSBio-580) and 1-[1-(4-chlorophenyl)-1H-[1,2,3]triazol-4-ylmethyl]-4-phenyl-piperazine (LASSBio-581). Binding studies performed on brain homogenate indicated that all three compounds bind selectively to D2 receptors. In addition, electrophysiological studies carried out in cultured hippocampal neurons suggested that LASSBio-579 and 581 act as D2 agonists, whereas LASSBio-580 acts as a D2 antagonist.

The N-methyl-D-aspartate neurotransmitter receptor is a mammalian brain target for the dinoflagellate Pfiesteria piscicida toxin.

Blooms of Pfiesteria piscicida, a dinoflagellate in eastern U.S. coastal rivers, are believed to secrete toxins that kill fish and produce short-term memory loss in humans.