AEA is synthesized and released “”on demand”" in neurons from its membrane precursor, N-arachidonoyl-phosphatidylethanolamine, by an N-acyl-phosphatidylethanolamine-specific phospholipase D (NAPE-PLD), and is inactivated by intracellular hydrolysis by fatty acid amide hydrolase (FAAH), whereas HKI-272 in vitro catechol-O-methyl-transferase (COMT) was suggested to inactivate NADAs. However, it is not known whether these enzymes or 12-LOX co-localize to any extent with TRPV1 receptors in the brain.

In this study we used immunohistochemical techniques (single peroxidase and double immunofluorescence staining), and analyzed the localization of the TRPV1 channel in mouse hippocampal and cerebellar neurons with respect to NAPE-PLD, ATM inhibitor FAAH, 12-LOX and COMT. Cycloxygenase-2 (COX-2), another putative AEA-degrading enzyme, was also studied. Co-localization between TRPV1 and either NAPE-PLD or FAAH, COX-2,12-LOX and COMT was found in Ammon’s horn (CA3) hippocampal pyramidal neurons and (with the exception of 12-LOX) in some Purkinje cells. At the cellular level, both anabolic and

catabolic enzymes appeared as fine grains with immunoperoxidase labeling and were observed in the soma-todendritic compartment of CA3 pyramidal cells as well as (with the exception of 12-LOX) in the cytoplasm of Purkinje neurons, in which FAAH and COX-2 immunoreactivities were, however, preferentially localized in the large extension of the dendritic arbor. Our data agree with the hypothesis that, in potential “”endovanillergic”" neurons, endogenous TRPV1 agonists, and AEA in particular, act as intracellular mediators by being produced from and/or degraded by the same mouse brain cells that express TRPV1 receptors. (c) 2008 IBRO. Published by Elsevier Ltd. All rights reserved.”
“Severe structural constraints

in the hepatitis A virus (HAV) capsid have been suggested as the reason for the lack of emergence of new serotypes in spite of the occurrence of complex distributions of mutants or quasi-species. Analysis of the HAV mutant spectra under immune pressure by the monoclonal antibodies (MAbs) K34C8 (immunodominant site) and H7C27 (glycophorin C59 nmr binding site) has revealed different evolutionary dynamics. Populations composed of complex ensembles of mutants with very low fitness or single dominant mutants with high fitness permit the acquisition of resistance to each of the MAbs, respectively. Deletion mutants were detected as components of the mutant spectra: up to 61 residues, with an average of 19, and up to 83 residues, with an average of 45, in VP3 and VP1 proteins, respectively. A clear negative selection of those replacements affecting the residues encoded by rare codons of the capsid surface has been detected through the present quasispecies analysis, confirming a certain beneficial role of such clusters.