Simulation of the song motor pathway in birds: A single neuron initiates a chain of events that produces birdsong with realistic spectra properties.

Cristiano Giordani,Sun Zhe,Ruggero Micheletto,Hector Rivera-Gutierrez,Gennady Cymbalyuk

doi:10.1371/journal.pone.0200998

Abstract

Birdsong is a complex learned behavior regulated by Neuromuscular coordination of different muscle sets necessary for producing relevant sounds. We developed a heterogeneous and stochastically connected neural network representing the pathway from the high vocal center (HVC) to the robust nucleus of the arcopallium (RA) neurons that drive the muscles to generate sounds. We show that a single active neuron is sufficient to initiate a chain of spiking events that results to excite the entire network system. The network could synthesize realistic bird sounds spectra, with spontaneous generation of intermittent sound bursts typical of birdsong (song syllables). This study confirms experiments on animals and on humans, where results have shown that single neurons are responsible for the activation of complex behavior or are associated with high-level perception events.

Highlights

Birds produce a large diversity of sounds, which usually include pure-tone whistles, broadband sounds, frequency and amplitude modulations, click-like sounds, and noise
Considering the fact that the neural pathway simulated in the model is extremely simple and triggered by a single activating neuron, the similarities between the real sounds and the simulated one are striking
The simulation demonstrates that it is possible to build a simple neuronal pathway that realizes complex sounds strikingly similar to birdsongs. It shows that a single neuronal activation can initiate the chain of events that leads to the song generation

Summary

Introduction

All these improvement and modernization of previous studies resulted in a persuasive evidence that complex behavior like sound generation in birds (a paradigm of language in superior animals) can be initiated by a single neuron that drives a small sized network pathway, supporting many outstanding experiments on humans and animals [19,20,21,22]. We use a realistic and biological plausible network model (an Izhikevich spiking network [18]) to reproduce the neurological pathway from the HVC to the robust nucleus of the arcopallium (RA) that drives muscle tension for the bird labial oscillation [15, 16].

Results

Conclusion