open access

https://hdl.handle.net/2115/76219

Inter- and intra-specific differences in muscarinic acetylcholine receptor expression in the neural pathways for vocal learning in songbirds

英語

vocal learning

2018-12-01

John Wiley & Sons

The journal of comparative neurology

526(17)

2856-2869

Acetylcholine receptors (AChRs) abound in the central nervous system of vertebrates. Muscarinic AChRs (mAChRs), a functional subclass of AChRs, mediate neuronal responses via intracellular signal transduction. They also play roles in sensorimotor coordination and motor skill learning by enhancing cortical plasticity. Learned birdsong is a complex motor skill acquired through sensorimotor coordination during a critical period. However, the functions of AChRs in the neural circuits for vocal learning and production remain largely unexplored. Here, we report the unique expression of mAChRs subunits (chrm2-5) in the song nuclei of zebra finches. The expression of excitatory subunits (chrm3 and chrm5) was downregulated in the song nuclei compared with the surrounding brain regions. In contrast, the expression of inhibitory mAChRs (chrm2 and chrm4) was upregulated in the premotor song nucleus HVC relative to the surrounding nidopallium. Chrm4 showed developmentally different expression in HVC during the critical period. Compared with chrm4, individual differences in chrm2 expression emerged in HVC early in the critical period. These individual differences in chrm2 expression persisted despite testosterone administration or auditory deprivation, which altered the timing of song stabilization. Instead, the variability in chrm2 expression in HVC correlated with parental genetics. In addition, chrm2 expression in HVC exhibited species differences and individual variability among songbird species. These results suggest that mAChRs play an underappreciated role in the development of species and individual differences in song patterns by modulating the excitability of HVC neurons, providing a potential insight into the gating of auditory responses in HVC neurons.

学術雑誌論文

Accepted Manuscript

This is the peer reviewed version of the following article: The journal of comparative neurology. Volume526, Issue17, December 1, 2018. Pages 2856-2869, which has been published in final form at https://doi.org/10.1002/cne.24532 . This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.

0021-9967