title: Increased messenger RNA expression of the 695 and 751 amino acid isoforms of the beta-amyloid protein precursor in the thalamus of 17-year-old cynomolgus (Macaca fascicularis) monkeys.
abstract: The levels of expression of messenger RNAs of the 695 and 751 amino acid isoforms of the beta-amyloid protein precursor in the brains of three-year-old and 17-year-old cynomolgus monkeys (Macaca fascicularis) were visualized and quantified by in situ hybridization histochemistry using 35S-labelled oligonucleotide probes. The analysis was carried out on coronal brain sections taken through the hippocampus and thalamus at the level of the geniculate nuclei. High densities of beta-amyloid protein precursor695 and beta-amyloid protein precursor751 messenger RNAs were found in the medial aspects of the mediodorsal, centromedian and parafascicular nuclei of the 17-year-old monkeys. The messenger RNA levels of the 695 and 751 isoforms were about two- and seven-fold, respectively, those found in the same nuclei of the three-year-old animals. The levels of these messenger RNA transcripts in the 17-year-old monkeys were not significantly different from those in the three-year-old animals in other brain areas e.g. the temporal cortex, entorhinal cortex and hippocampus. No Alzheimer's disease-like neuropathology in terms of diffuse or senile beta-amyloid plaques, dystrophic neurites or neurofibrillary tangles were detectable by specific innumohistochemical procedures in the above thalamic nuclei of the 17-year-old animals. In addition no reactive gliosis was seen in the thalamus of these monkeys.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Merck Sharp and Dohme Research Laboratories, Neuroscience Research Centre, Harlow, Essex, UK.
authors.forename: D J
authors.initials: DJ
authors.lastname: Sirinathsinghji
authors.forename: M
authors.initials: M
authors.lastname: Rigby
authors.forename: R P
authors.initials: RP
authors.lastname: Heavens
authors.forename: D
authors.initials: D
authors.lastname: Smith
authors.forename: J M
authors.initials: JM
authors.lastname: Fernandez
authors.forename: R
authors.initials: R
authors.lastname: Schuligoi
authors.forename: R G
authors.initials: RG
authors.lastname: Hill
mesh_terms: D000375:Aging; D016564:Amyloid beta-Protein Precursor / Q000235:genetics*; D000818:Animals; D001345:Autoradiography; D005260:Female; D017403:In Situ Hybridization; D008252:Macaca fascicularis; D012333:RNA, Messenger / Q000235:genetics*; D013788:Thalamus
chemical_list: D016564:Amyloid beta-Protein Precursor; D012333:RNA, Messenger