J Neurophysiol (May 1, 2003). 10.1152/jn.00801.2002
Submitted on Submitted 12 September 2002; accepted in final form 13 January 2003

Model of Song Selectivity and Sequence Generation in Area HVc of the Songbird

Volen Center for Complex Systems and Department of Biology, Brandeis University, Waltham, Massachusetts 02454-9110

Drew, Patrick J. and L. F. Abbott. Model of Song Selectivity and Sequence Generation in Area HVc of the Songbird. J. Neurophysiol. 89: 2697-2706, 2003. In songbirds, nucleus HVc plays a key role in the generation of the syllable sequences that make up a song. Auditory responses of neurons in HVc are selective for single syllables and for combinations of syllables occurring in temporal sequences corresponding to those in the bird's own song. We present a model of HVc that produces syllable- and temporal-combination-selective responses on the basis of input from recorded bird songs filtered through spectral temporal receptive fields similar to those measured in field L, a primary auditory area. Normalization of the field L outputs, similar to that proposed in models of visual processing, plays an important role in the generation of syllable-selective responses in the model. For temporal-combination-selective responses, N-methyl-D-aspartate (NMDA) conductances provide a memory that allows inhibitory neurons to gate responses to a final syllable in a sequence on the basis of responses to earlier syllables. When the same network that produces temporal-combination-selective responses is excited by a nonspecific timing signal, it generates a similar pattern of output as it does in response to auditory song input. Thus the same model network can perform both sensory and motor functions.