title: Annual life-history dependent seasonal differences in neural activity of the olfactory system between non-migratory and migratory songbirds.
abstract: Present study investigated seasonal plasticity in neural activity of the olfactory system, and assessed whether this was influenced by differences in seasonal life-history states (LHSs) between the non-migratory and migratory birds. Brains of non-migratory Indian weaver birds and migratory redheaded buntings were processed for ZENK immunohistochemistry, a marker of neuronal activation, at the times of equinoxes (March, September) and solstices (June, December), which correspond with the periods of different seasonal LHSs during the year. Immunoreactivity was quantified in brain regions comprising the olfactory system viz. olfactory bulb (OB), anterior olfactory nucleus (AON), prepiriform cortex (CPP), lateral olfactory tract (LOT) and olfactory cortex (piriform cortex, CPI; lateral olfactory cortex, LOC). In weaver birds, ZENK-like immunoreactive (ZENK-lir) cells were significantly higher in all the brain areas during post-breeding season (September) than during the other seasons; OBs had higher neuronal activity in the breeding season (June), however. A similar neural activity pattern but at enhanced levels was found in migratory buntings almost all the year. These results for the first time show LHS-associated differences in the seasonal plasticity of a sensory system between the non-migratory and migratory songbirds.
authors.affiliation: DST-IRHPA Centre for Excellence in Biological Rhythms Research and IndoUS Centre for Biological Timing, Department of Zoology, University of Lucknow, Lucknow 226 007, India.
authors.forename: Ashutosh
authors.initials: A
authors.lastname: Rastogi
authors.affiliation: DST-IRHPA Centre for Excellence in Biological Rhythms Research and IndoUS Centre for Biological Timing, Department of Zoology, University of Delhi, Delhi 110 007, India.
authors.lastname: Surbhi
authors.affiliation: DST-IRHPA Centre for Excellence in Biological Rhythms Research and IndoUS Centre for Biological Timing, Department of Zoology, University of Lucknow, Lucknow 226 007, India.
authors.forename: Shalie
authors.initials: S
authors.lastname: Malik
authors.affiliation: DST-IRHPA Centre for Excellence in Biological Rhythms Research and IndoUS Centre for Biological Timing, Department of Zoology, University of Lucknow, Lucknow 226 007, India.
authors.forename: Sangeeta
authors.initials: S
authors.lastname: Rani
authors.affiliation: DST-IRHPA Centre for Excellence in Biological Rhythms Research and IndoUS Centre for Biological Timing, Department of Zoology, University of Delhi, Delhi 110 007, India. Electronic address: drvkumar11@yahoo.com.
authors.forename: Vinod
authors.initials: V
authors.lastname: Kumar
mesh_terms: D025041:Animal Migration / Q000502:physiology*; D000818:Animals; D051766:Early Growth Response Protein 1 / Q000378:metabolism*; D007150:Immunohistochemistry; D009473:Neuronal Plasticity / Q000502:physiology*; D009830:Olfactory Bulb / Q000378:metabolism*; D066194:Olfactory Cortex / Q000378:metabolism*; D066195:Piriform Cortex / Q000378:metabolism*; D012621:Seasons; D020308:Songbirds / Q000502:physiology*
chemical_list: D051766:Early Growth Response Protein 1
keywords: Indian weaver bird; Olfaction; Redheaded bunting; Songbirds; ZENK