Systemic D1-like receptor activation during song exposure biases the emergence of song selectivity in the juvenile zebra finch NCM

Abstract

Vocal learning requires juveniles to form auditory representations of adult vocal models that guide vocal practice. The caudomedial nidopallium (NCM), a higher-order auditory pallial region in songbirds, has been implicated in tutor-song memory and receives dopaminergic input, but whether dopamine receptor activation biases the emergence of song-specific selectivity during development remains unclear. We recorded NCM single-unit activity in juvenile male zebra finches with limited tutor-song exposure. One adult song was repeatedly presented after systemic administration of the D1-like receptor agonist SKF-38393, the D2-like receptor agonist quinpirole, or saline, and neural selectivity was assessed before and after pairing. Pairing did not produce a uniform population-wide shift in average selectivity. However, a linear mixed-effects model accounting for pre-pairing selectivity and multiple units per bird revealed significantly higher post-pairing selectivity in SKF-treated units than in saline-treated units. SKF-treated units also differed from quinpirole-treated units, whereas quinpirole and saline did not differ. Among initially non-selective units, threshold-defined gains occurred in 31.3% of SKF, 15.4% of saline, and 10.8% of quinpirole units, with SKF showing the highest gained fraction across all tested thresholds. Although the exact bird-label permutation test was not significant, continuous and threshold-based analyses provided convergent unit-level evidence for an SKF-associated enhancement of paired-song selectivity. These findings support neuromodulatory gating as a potential mechanism by which developmental auditory experience shapes stimulus-specific sensory representations.

The authors' abstract, as published at the source. Neuroscience Research, 2026 · DOI ↗