title: Effects of sex and seasonality on the song control system and FoxP2 protein expression in black-capped chickadees (Poecile atricapillus).
abstract: Plasticity in behavior is mirrored by corresponding plasticity in the brain in many songbird species. In some species, song system nuclei (Phillmore et al. [2006]: J Neurobiol 66:1002-1010) are larger in birds in breeding condition than birds in nonbreeding condition, possibly due to increased vocal output in spring. FOXP2, a transcription factor associated with language expression and comprehension in humans and song learning in songbirds, also shows plasticity. FoxP2 expression in songbird Area X, a region important for sensorimotor integration, is related to developmental and adult vocal plasticity (Teramitsu et al. [2010]: J Neurosci 24:3152-3163, Chen et al. [2013], J Exp Biol 216:3682-3692). In this study, we examined whether sex and breeding condition affects both song control system volume (HVC, X) and FoxP2 protein expression in black-capped chickadees (Poecile atricapillus). HVC volume was larger in males in breeding condition than males in nonbreeding condition, but there were no sex differences. In contrast, Area X volume was larger in males than females, regardless of breeding condition, likely reflecting that male and female chickadees produce learned chick-a-dee calls year round, but output of the learned song increases in breeding males. FoxP2 protein levels did not differ between sexes or breeding condition when calculated as a ratio of labeled cells in Area X to labeled cells in the surrounding striato-pallium, however, absolute density of FoxP2 in both regions was higher in males than in females. This may indicate that chickadees maintain a level of FoxP2 necessary for plasticity year-round, but males have greater potential for plasticity compared to females.
authors: Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, B3R 4H2, Canada.
authors: Leslie S
authors: LS
authors: Phillmore
authors: Heather L
authors: HL
authors: MacGillivray
authors: K Ryan
authors: KR
authors: Wilson
authors: Stephanie
authors: S
authors: Martin
mesh_terms: D000818:Animals; D030161:Avian Proteins / Q000378:metabolism*; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology*; D005260:Female; D051858:Forkhead Transcription Factors / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D009929:Organ Size; D012621:Seasons; D012727:Sex Characteristics; D012726:Sexual Behavior, Animal / Q000502:physiology; D020308:Songbirds / Q000033:anatomy & histology / Q000502:physiology*; D014828:Vocalization, Animal / Q000502:physiology
chemical_list: D030161:Avian Proteins; D051858:Forkhead Transcription Factors
keywords: FoxP2; chickadees; seasonality; sex differences; song system