Commentary on "Modeling temperature manipulation in a circular model of birdsong production"

Abstract

The paper titled "Modeling temperature manipulations in a circular model of birdsong production" by Dima et al. [1] suggests that the birdsong system has a circular architecture in which an initiating area in the brainstem provides inputs to both the downstream respiratory area and the upstream vocal control area; the latter subsequently sends input to the respiratory area as well. A consequence of the proposed architecture is that the birdsong syllables are generated by the neural commands at two different timescales corresponding to the two inputs. The model is successful in explaining the syllable stretching and breaking phenomena when an upstream vocal area is cooled down. In this commentary, I make some remarks on the findings of this paper and discuss how this work fits into the current knowledge about birdsong generation.The avian vocal production system has long been understood as a feedforward network mainly implemented by a descending motor pathway. In this picture, a forebrain area HVC (high vocal center, as a proper name) generates the precisely timed sequential actions of this complex vocal behavior. The projection neurons in HVC fire sparsely at specific time points of the song. These activities activate the downstream RA (the robust nucleus of the arcopallium) where the motor patterns are generated by the activation of a subset of the RA neu- *