title: Dissociable effects of social context on song and doublecortin immunoreactivity in male canaries.
abstract: Variation in environmental factors such as day length and social context greatly affects reproductive behavior and the brain areas that regulate these behaviors. One such behavior is song in songbirds, which males use to attract a mate during the breeding season. In these species the absence of a potential mate leads to an increase in the number of songs produced, while the presence of a mate greatly diminishes singing. Interestingly, although long days promote song behavior, producing song itself can promote the incorporation of new neurons in brain regions controlling song output. Social context can also affect such neuroplasticity in these song control nuclei. The goal of the present study was to investigate in canaries (Serinus canaria), a songbird species, how photoperiod and social context affect song and the incorporation of new neurons, as measured by the microtubule-associated protein doublecortin (DCX) in HVC, a key vocal production brain region of the song control system. We show that long days increased HVC size and singing activity. In addition, male canaries paired with a female for 2 weeks showed enhanced DCX-immunoreactivity in HVC relative to birds housed alone. Strikingly, however, paired males sang fewer songs that exhibited a reduction in acoustic features such as song complexity and energy, compared with birds housed alone, which sang prolifically. These results show that social presence plays a significant role in the regulation of neural and behavioral plasticity in songbirds and can exert these effects in opposition to what might be expected based on activity-induced neurogenesis.
authors: Department of Psychological and Brain Sciences, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD, 21218-2686, USA.
authors: Beau A
authors: BA
authors: Alward
authors: Wade D
authors: WD
authors: Mayes
authors: Katherine
authors: K
authors: Peng
authors: Tyler J
authors: TJ
authors: Stevenson
authors: Jacques
authors: J
authors: Balthazart
authors: Gregory F
authors: GF
authors: Ball
mesh_terms: D000162:Acoustics; D000818:Animals; D030161:Avian Proteins / Q000378:metabolism*; D001921:Brain / Q000502:physiology*; D002171:Canaries / Q000502:physiology*; D002452:Cell Count; D000089622:Doublecortin Domain Proteins; D007150:Immunohistochemistry; D008297:Male; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D009474:Neurons / Q000502:physiology; D009479:Neuropeptides / Q000378:metabolism*; D017440:Photoperiod; D012919:Social Behavior; D014828:Vocalization, Animal / Q000502:physiology*
chemical_list: D030161:Avian Proteins; D000089622:Doublecortin Domain Proteins; D008869:Microtubule-Associated Proteins; D009479:Neuropeptides
keywords: canary; neurogenesis; plasticity; songbird