Independent effects of song quality and experience with photostimulation on expression of the immediate, early gene ZENK (EGR‐1) in the auditory telencephalon of female European starlings

Abstract

Age influences behavioral decisions such as reproductive timing and effort. In photoperiodic species, such age effects may be mediated, in part, by the individual's age-accrued experience with photostimulation. In female European starlings (Sturnus vulgaris) that do not differ in age, experimental manipulation of photostimulation experience (photoexperience) affects hypothalamic, pituitary, and gonadal activity associated with reproductive development. Does photoexperience also affect activity in forebrain regions involved in processing a social cue, the song of males, which can influence mate choice and reproductive timing in females? Female starlings prefer long songs over short songs in a mate-choice context, and, like that in other songbird species, their auditory telencephalon plays a major role in processing these signals. We manipulated the photoexperience of female starlings, photostimulated them, briefly exposed them to either long or short songs, and quantified the expression of the immediate-early gene ZENK (EGR-1) in the caudomedial nidopallium as a measure of activity in the auditory telencephalon. Using an information theoretic approach, we found higher ZENK immunoreactivity in females with prior photostimulation experience than in females experiencing photostimulation for the first time. We also found that long songs elicited greater ZENK immunoreactivity than short song did. We did not find an effect of the interaction between photoexperience and song length, suggesting that photoexperience does not affect forebrain ZENK-responsiveness to song quality. Thus, photoexperience affects activity in an area of the forebrain that processes social signals, an effect that we hypothesize mediates, in part, the effects of age on reproductive decisions in photoperiodic songbirds.

Mate Selection, Sexual Orientation, and Pair Bonding

“…[206][207][208][209] The song repertoire has been specifically shown to represent an honest signal predicting the future parental (paternal) investment of a male bird 206 (see Ref. [206][207][208][209] The song repertoire has been specifically shown to represent an honest signal predicting the future parental (paternal) investment of a male bird 206 (see Ref.…”

Estradiol-dependent modulation of auditory processing and selectivity in songbirds

“…Throughout most of NCM, responses to sound are organized tonotopically [166,198], and the ZENK response to song is generally more robust in the dorsomedial aspect than the ventro-lateral aspect ([9,66,113,120,148,185,187,201,210], cf. [54]).…”

Prior Experience with Photostimulation Enhances Photo-Induced Reproductive Response in Female House Finches

“…In photostimulated European starlings 541 prior photoexperience increases the responsiveness of specific brain regions involved in 542 song perception (Sockman and Ball, 2009). Similarly, photorefractory adult European 543 starlings with prior photoexperience, and thus prior exposure to elevated levels of 544 GnRH, exhibited a larger LH response following exogenous GnRH administration than 545 photorefractory juveniles that have not been previously exposed to elevated GnRH 546 levels (McNaughton et al, 1995).…”