title: COX-2, a synaptically induced enzyme, is expressed by excitatory neurons at postsynaptic sites in rat cerebral cortex.
abstract: Postnatal development and adult function of the central nervous system are dependent on the capacity of neurons to effect long-term changes of specific properties in response to neural activity. This neuronal response has been demonstrated to be tightly correlated with the expression of a set of regulatory genes which include transcription factors as well as molecules that can directly modify cellular signaling. It is hypothesized that these proteins play a role in activity-dependent response. Previously, we described the expression and regulation in brain of an inducible form of prostaglandin synthase/cyclooxygenase, termed COX-2. COX-2 is a rate-limiting enzyme in prostanoid synthesis and its expression is rapidly regulated in developing and adult forebrain by physiological synaptic activity. Here we demonstrate that COX-2 immunoreactivity is selectively expressed in a subpopulation of excitatory neurons in neo-and allocortices, hippocampus, and amygdala and is compartmentalized to dendritic arborizations. Moreover, COX-2 immunoreactivity is present in dendritic spines, which are specialized structures involved in synaptic signaling. The developmental profile of COX-2 expression in dendrites follows well known histogenetic gradients and coincides with the critical period for activity-dependent synaptic remodeling. These results suggest that COX-2, and its diffusible prostanoid products, may play a role in postsynaptic signaling of excitatory neurons in cortex and associated structures.
authors.affiliation: Department of Pathology, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA.
authors.forename: W E
authors.initials: WE
authors.lastname: Kaufmann
authors.forename: P F
authors.initials: PF
authors.lastname: Worley
authors.forename: J
authors.initials: J
authors.lastname: Pegg
authors.forename: M
authors.initials: M
authors.lastname: Bremer
authors.forename: P
authors.initials: P
authors.lastname: Isakson
mesh_terms: D000367:Age Factors; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D002540:Cerebral Cortex / Q000201:enzymology*; D051546:Cyclooxygenase 2; D003712:Dendrites / Q000201:enzymology; D017781:Genes, Immediate-Early; D007527:Isoenzymes / Q000378:metabolism*; D008297:Male; D044262:Prostaglandin H2; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*; D011463:Prostaglandins H / Q000096:biosynthesis; D051381:Rats; D013569:Synapses / Q000201:enzymology*
chemical_list: D000911:Antibodies, Monoclonal; D007527:Isoenzymes; D011463:Prostaglandins H; D044262:Prostaglandin H2; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases