Neural expression of two immediate early genes do not differ in response to novel objects in neophobic and non-neophobic house sparrows (Passer domesticus)


SOCIETY FOR INTEGRATIVE AND COMPARATIVE BIOLOGY
2021 VIRTUAL ANNUAL MEETING (VAM)
January 3 – Febuary 28, 2021

Meeting Abstract


82-3  Sat Jan 2  Neural expression of two immediate early genes do not differ in response to novel objects in neophobic and non-neophobic house sparrows (Passer domesticus) Kimball, MG*; Kelly, TR; Stansberry, KR; Lattin, CR; Louisiana State University ; Louisiana State University ; Louisiana State University ; Louisiana State University mkimba6@lsu.edu

Neophobia is a specific type of exploration-avoidance behavior, and it is a personality trait with critical ecological relevance, because it affects whether animals will be able to adapt to new environments and exploit novel resources. Despite its importance, the neurobiological mechanisms underlying neophobia are still poorly understood. In this study we examined regional brain activity using immediate early gene (IEG) expression in response to novel objects in captive house sparrows (Passer domesticus, n=24). We predicted non-neophobic individuals would show decreased neuronal activity in brain regions involved in fear and anxiety (e.g., nucleus taeniae of the amygdala), and increased activity in brain regions involved in learning and memory (e.g., striatum) than neophobic individuals. To classify birds by phenotype, we used behavior trials that tested willingness to approach a food dish in the presence of several different novel objects, habituation to one novel object, and willingness to try novel foods. We then exposed birds to a new novel object and assessed protein expression of two IEGs in neophobic vs non-neophobic individuals after this final exposure. Sparrows showed clear phenotypic distinctions, with a third of individuals showing highly neophobic behavior, a third highly non-neophobic behavior, and a third intermediate behavior. There was also high repeatability of novel object responses (r=0.51). However, we saw no differences between neophobic and non-neophobic birds in IEG expression in response to novel objects in any of the 5 brain regions examined. This suggests that neophobia is not caused by different patterns of overall activity in brain regions involved in responding to threats, learning, or memory.

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