title: Noradrenergic regulation of plasticity marker expression in the adult rodent piriform cortex.
abstract: The adult rodent piriform cortex has been reported to harbor immature neurons that express markers associated with neurodevelopment and plasticity, namely polysialylated neural cell adhesion molecule (PSA-NCAM) and doublecortin (DCX). We characterized the expression of PSA-NCAM and DCX across the rostrocaudal axis of the rat piriform cortex and observed higher numbers of PSA-NCAM and DCX positive cells in the posterior subdivision. As observed in the rat piriform cortex, Nestin-GFP reporter mice also revealed a similar gradient of GFP-positive cells with an increasing rostro-caudal gradient of expression. Given the extensive noradrenergic innervation of the piriform cortex and its role in regulating piriform cortex function and synaptic plasticity, we addressed the influence of norepinephrine (NE) on piriform cortex plasticity marker expression. Depletion of NE by treatment with the noradrenergic neurotoxin DSP-4 significantly increased the number of DCX and PSA-NCAM immunopositive cells in the piriform cortex of adult rats. Similarly, DSP-4 treated Nestin-GFP reporter mice revealed a robust induction of GFP-positive cells within the piriform cortex following NE depletion. Genetic loss of NE in dopamine β-hydroxylase knockout (Dbh -/-) mice phenocopied the effects of DSP-4, with an increase noted in PSA-NCAM and DCX positive cells in the piriform cortex. Further, chronic α2-adrenergic receptor stimulation with the agonist guanabenz increased PSA-NCAM and DCX positive cells in the piriform cortex of adult rats and GFP-positive cells in the piriform cortex of Nestin-GFP mice. By contrast, chronic α2-adrenergic receptor blockade with the antagonist yohimbine reduced PSA-NCAM and DCX positive cells in the piriform cortex of adult rats. Our results provide novel evidence for a role of NE in regulating the expression of plasticity markers, including PSA-NCAM, DCX, and nestin, within the adult mouse and rat piriform cortex.
authors.affiliation: Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India, India.
authors.forename: Krishna C
authors.initials: KC
authors.lastname: Vadodaria
authors.affiliation: Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India, India.
authors.forename: Sudhirkumar U
authors.initials: SU
authors.lastname: Yanpallewar
authors.affiliation: Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India, India.
authors.forename: Mayur
authors.initials: M
authors.lastname: Vadhvani
authors.affiliation: Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India, India.
authors.forename: Devyani
authors.initials: D
authors.lastname: Toshniwal
authors.affiliation: Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA, USA.
authors.forename: L Cameron
authors.initials: LC
authors.lastname: Liles
authors.affiliation: Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA, USA.
authors.forename: Karen S
authors.initials: KS
authors.lastname: Rommelfanger
authors.affiliation: Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA, USA.
authors.forename: David
authors.initials: D
authors.lastname: Weinshenker
authors.affiliation: Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India, India. Electronic address: vvaidya@tifr.res.in.
authors.forename: Vidita A
authors.initials: VA
authors.lastname: Vaidya
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis; D000089622:Doublecortin Domain Proteins; D000089662:Doublecortin Protein; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008869:Microtubule-Associated Proteins / Q000096:biosynthesis; D064231:Nestin / Q000096:biosynthesis; D019006:Neural Cell Adhesion Molecules / Q000096:biosynthesis; D009473:Neuronal Plasticity / Q000502:physiology*; D009479:Neuropeptides / Q000096:biosynthesis; D009638:Norepinephrine / Q000378:metabolism*; D066195:Piriform Cortex / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D015415:Biomarkers; C000714328:DCX protein, human; C000714847:Dcx protein, mouse; C000714848:Dcx protein, rat; D000089622:Doublecortin Domain Proteins; D000089662:Doublecortin Protein; D008869:Microtubule-Associated Proteins; D064231:Nestin; D019006:Neural Cell Adhesion Molecules; D009479:Neuropeptides; D009638:Norepinephrine
keywords: DCX; DSP-4; Dbh; Doublecortin; Nestin; Neurogenesis; Norepinephrine; PSA-NCAM; α(2)-Adrenergic receptor