The Vocal Control System of the Budgerigar
The vocal control system of the budgerigar consists of a set of interconnected vocal control nuclei which link auditory areas of the brain with the basal ganglia and descending vocal motor pathways. Vocal pathways are bilateral and symmetrical in budgerigars, however for simplicity of representation, descending pathways are shown on the left side of the drawing and ascending pathways on the right side.
The parrot vocal system possesses a number of interesting similarities to the songbird system including the existence of a cell group in the arcopallium (formerly the archistriatum)(AAC) which is the source of long projections to the brainstem as well as nuclei in the basal ganglia (MStrm) and thalamus (DMm) which form an accessory or anterior forebrain pathway. There are two important differences between the parrot system and the songbird system -
The following references are suggested for the interested reader:
Brauth, S. E., Heaton, J. T., Durand, S. E., Liang, W. and Hall, W. S. (1994) Functional anatomy of forebrain auditory pathways in the budgerigar (Melopsittacus undulatus). Brain Beh. Evol., 44:210-233.
Durand, S. E., Heaton, J. T., Amateau, S. and Brauth, S. E. (1997) Vocal control pathways through the anterior forebrain of a parrot (Melopsittacus undulatus). J. Comp. Neur. 377:179-206.
Farabaugh, S. M. and Wild, J. M. (1997) Reciprocal connections between primary and secondary auditory pathways in the telencephalon of the budgerigar (Melopsittacus undulatus). Brain Res., 747:18-25.
Jarvis, E. D. and Mello, C. (2000) Molecular mapping of brain areas involved in parrot vocal communication. J. Comp. Neurol., 419:1-31
Brauth, S., Liang, W., Roberts, T. F., Scott, L. L. and Quinlan, E. M. (2002) Contact call-driven zenk protein induction and habituation in telencephalic auditory pathways in the budgerigar (Melopsittacus undulatus): Implications for understanding vocal learning processes. Learning and Memory, 9:76-88.
Brauth, S. E., Liang, W. and Roberts, T. F. (2001) Projections of the oval nucleus of the hyperstriatum ventrale in the budgerigar: Relationships with the auditory system. J. Comp. Neur., 432:481-511.
Heaton, J. T. and Brauth, S. E. (2000a) Effects of lesions of the central nucleus of the anterior archistriatum on contact call and warble song production in the Budgerigar (Melopssitacus undulatus). Neurobiol. Learning Memory, 73:207-242.
Heaton, J. T. and Brauth, S. E. (2000b) Telencephalic nuclei control late but not early nestling calls in the budgerigar. Beh. Brain Res. 109:129-135.
Paton, J. A., Manogue, K. R. and Nottebohm, F. (1981) Bilateral organization of the vocal control pathway in the budgerigar (Melopsittacus undulatus) J. Neurosci. 1:1279-1288.
Striedter, G. (1994) The vocal control pathways in budgerigars differ from those in songbirds. J. Comp. Neur. 343:35-56.