Active immunization against vasoactive intestinal polypeptide decreases neuronal recruitment and inhibits reproduction in zebra finches

Abstract

Neurogenesis and neuronal recruitment occur in adult brains of many vertebrates, and the hypothesis is that these phenomena contribute to the brain plasticity that enables organisms to adjust to environmental changes. In mammals, vasoactive intestinal polypeptide (VIP) is known to have many neuroprotective properties, but in the avian brain, although widely distributed, its role in neuronal recruitment is not yet understood. In the present study we actively immunized adult zebra finches against VIP conjugated to KLH and compared neuronal recruitment in their brains, with brains of control birds, which were immunized against KLH. We looked at two forebrain regions: the nidopallium caudale (NC), which plays a role in vocal communication, and the hippocampus (HC), which is involved in the processing of spatial information. Our data demonstrate that active immunization against VIP reduces neuronal recruitment, inhibits reproduction, and induces molting, with no change in plasma prolactin levels. Thus, our observations suggest that VIP has a direct positive role in neuronal recruitment and reproduction in birds. J. Comp. Neurol. 524:2516-2528, 2016. © 2016 Wiley Periodicals, Inc.

Sex-and Region-Dependent Expression of the Autism-Linked ADNP Correlates with Social- and Speech-Related Genes in the Canary Brain

“…VIP is highly conserved across species (Bodner et al 1985;Giladi et al 1990) and found identical in many mammals (Giladi et al 1990) with minor differences observed between human and chicken (Nussdorfer and Malendowicz 1998;Nowak et al 2003). In birds, VIP was previously associated with pair bonding and social and parental behaviors (Kingsbury et al 2013;Kingsbury and Goodson 2014;Kingsbury et al 2015;Vistoropsky et al 2016). In our canaries, VIP expression of both sexes was increased in the cerebrum and brain stem with significantly less expression in the cerebellum (Fig.…”

Artificial Light at Night Increases Recruitment of New Neurons and Differentially Affects Various Brain Regions in Female Zebra Finches

“…At the end of the experiment, the birds were weighed, killed and the brains were sectioned as described in [ 8 ]. Then, sections were processed for immunohistochemistry as described in [ 55 ]. Sections were incubated for 48 h at 4 °C, with primary antibodies: rat anti-BrdU IgG2a (diluted 1:200, Vector Labs, Burlingame, CA, USA) and neuronal specific antibody, anti-HuC/HuD mouse IgG2b, monoclonal 16A11 (diluted 1:200, Invitrogen, CarlsbaD, CA, USA).…”

Questioning Seasonality of Neuronal Plasticity in the Adult Avian Brain

“…100 mg/kg) of bromodeoxyuridine (BrdU; SigmaUltra, diluted 10 mg/ml in sterile water; Sigma). BrdU is a cell birth-date marker, and our dose is the same as previously used to study adult neurogenesis in this species 43 – 45 . Then, the birds were kept under the same conditions for additional 24 days, a period that allows enough time for neurons born at the time of treatment to migrate to their final destination, undergo final anatomical differentiation 46 , 47 , and incorporate into functional neural circuits 4 .…”

“…Twenty four days after BrdU treatment the birds were weighed, killed, their brains were fixed, embedded, cut transversely at 6 µm intervals, and processed for immunohistochemical staining as we described in details previously (e.g. 45 ). In short, we used double-labeling fluorescence staining: Hu (a neuronal specific marker) was stained green in the cytoplasm of all neurons, and BrdU (the cell birth-date marker) was stained red in the nuclei of new neurons.…”

“…In each brain and for each region, we also measured the nuclear diameters of ten BrdU labeled neurons, and those of a sample of all neurons (labeled and unlabeled), as described in Vistoropsky et al . 45 . The values of section thickness and the mean neuronal nuclear diameter of labeled neurons in a certain brain region served to estimate the number of new neurons per mm 3 in each section and compensate for over-counting [number of cells/mm 3 = number of cells/area * (T/(T + D)]; where T = section thickness (6 µm, as indicated above) and D = mean nuclear diameter], using the Abercrombie stereological correction equation 49 .…”