COX-2, a Synaptically Induced Enzyme, is Expressed by Excitatory Neurons at Postsynaptic Sites in Rat Cerebral Cortex

• Published in: Proceedings of the National Academy of Sciences - PNAS 1996-03, Vol.93 (6), p.2317-2321
• Main Authors: Kaufmann, Walter E., Worley, Paul F., Pegg, Jodi, Bremer, Margaret, Isakson, Peter
• Format: Article
• Language: English
• Subjects: Age Factors; Animals; Antibodies; Antibodies, Monoclonal - immunology; Antibody Specificity; Brain; Cellular immunity; Cerebral Cortex - enzymology; Cyclooxygenase 2; Dendrites; Dendrites - enzymology; Dendritic spines; Enzymes; Genes, Immediate-Early; Hippocampus; Immunity (Disease); Isoenzymes - metabolism; Male; Neurons; Prostaglandin H2; Prostaglandin-Endoperoxide Synthases - metabolism; Prostaglandins; Prostaglandins H - biosynthesis; Pyramidal cells; Rats; Rodents; Synapses - enzymology; Tissue samples
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.93.6.2317

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 responses. Previously, we described the expression and regulation in brain of an inducible form of prostaglandin synthase/cyclooxygenase, termed COX-2. COX-2 is a ratelimiting 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.