Contents lists available at ScienceDirect Behavioural Processes journal homepage: www.elsevier.com/locate/behavproc The neural response of female zebra finches (Taeniopygia guttata) to conspecific, heterospecific, and isolate song depends on early-life song exposure Adriana Diez a,b, ⁎ , Alice Cui d , Scott A. MacDougall-Shackleton a,b,c,d a Advanced Facility for Avian Research, London, ON, Canada b Neuroscience Graduate Program, University of Western Ontario, London, ON, Canada. c Department of Psychology, University of Western Ontario, London, ON, Canada. d Department of Biology, University of Western Ontario, London, ON, Canada. ARTICLE INFO Keywords: Birdsong Vocal learning Zebra finch Bengalese finch ABSTRACT The auditory forebrain regions caudo-medial nidopallium (NCM) and caudo-medial mesopallium (CMM) of songbirds exhibit differential expression of the immediate-early gene ZENK in response to playback of different song stimuli, and dependent on early-life auditory experience. Similarly, song preferences depend both on au- ditory experience and unlearned biases for particular song features. We explored the contributions of early-life auditory experience and the type of song stimuli on the Zenk response in the auditory forebrain of female zebra finches. Females were raised in three different early tutoring conditions: conspecific tutors that sang isolate song, heterospecific tutors, or conspecific tutors that sang wild-type song. At maturity, these females were exposed to one of five different playback conditions: wild-type song, isolate song, tutor song, heterospecific song, or white noise. Subsequently, the number of cells immunoreactive for ZENK in CMM and NCM was measured. We pre- dicted that birds exposed to conspecific song early in life, and during the song playback in adulthood, would have the highest neural response. Instead, we found that the Zenk response varied across playback conditions with the highest response to conspecific wild-type and conspecific isolate song. In addition, we found a main effect of tutoring, with the lowest overall Zenk response in females tutored by males singing isolate song. Most importantly, there was a significant interaction in that females tutored by wild-type conspecific or heterospecific songs showed a similar increased response to zebra finch songs (wild-type or isolate), but females tutored by isolate song showed no differential response to conspecific song and only showed elevated Zenk response to the particular songs they were tutored with. Combined, our results indicate that unlearned response biases to conspecific song elements depend on previous auditory experience. That is, early experience appears to mod- ulate the expression of innate biases. 1. Introduction Acoustic communication requires that receivers perceive and dif- ferentially respond to signals. In songbirds, the neural processing and behavioural responding to conspecific vocalizations, similar to song production learning, depends on both innate biases and on early ex- perience. Adult female zebra finches (Taeniopygia guttata) prefer songs heard early in life compared to unfamiliar songs (Miller, 1979; Riebel et al., 2002), even if the unfamiliar song resembled their tutor song (songs of unfamiliar brothers; Riebel and Smallegange, 2003). This preference extends to songs of tutors that female zebra finches were exposed to at various stages of development (Holveck and Riebel, 2014). The influence of the early acoustic experience goes beyond song familiarity and also affects preferences for song types or acoustic fea- tures of song. For example, female zebra finches reared in the absence of tutors did not prefer normal tutor songs more than abnormal songs from isolate reared males (Lauay et al., 2004). Similarly, neural re- sponses in the auditory forebrain of cross-fostered (by Bengalese fin- ches, Lonchura striata domestica) female zebra finches were similar in response to songs of the foster father compared to unfamiliar male Bengalese song. This similarity was also found in comparison with unfamiliar conspecific and Bengalese finch song, but the response was greater to unfamiliar songs of the foster species over a third species of finches (Woolley et al., 2010; Hauber et al., 2013). However, early acoustic experience is not the only factor shaping adult female song preferences. Non-learned, or innate, biases guide https://doi.org/10.1016/j.beproc.2017.12.022 Received 1 April 2017; Received in revised form 19 November 2017; Accepted 20 December 2017 ⁎ Corresponding author at: Advanced Facility for Avian Research, London, ON, Canada. E-mail address: bdiezmed@uwo.ca (A. Diez). Behavioural Processes 163 (2019) 37–44 Available online 21 December 2017 0376-6357/ © 2017 Elsevier B.V. All rights reserved. T