William Sterling Hall

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Hodological, electrophysiological, and ablation studies indicate a role for the basal forebrain in telencephalic vocal control; however, to date the organization of the basal forebrain has not been extensively studied in any nonmammal or nonhuman vocal learning species. To this end the chemical anatomy of the avian basal forebrain was investigated in a(More)
The connections of a higher order auditory area in the neostriatum intermedium pars ventrolateralis (NIVL) were mapped with pathway tracing techniques in order to elucidate possible pathways by which auditory feedback may influence vocal learning in the budgerigar (Melopsittacus undulatus). Previous research has shown that NIVL receives projections from(More)
Interconnections of forebrain auditory and vocal control nuclei were mapped in the budgerigar using pathway tracing techniques. The anatomical results indicate four circuits by which auditory information may influence the vocal motor system: (1) direct auditory thalamic projections from nucleus dorsomedialis posterior (DMP) to both the neostriatal higher(More)
The present study used histochemical methods to map the distributions of choline acetyl transferase (ChAT) and acetylcholinesterase (AChE) in the vocal control nuclei of a psittacine, the budgerigar (Melopsittacus undulatus). The distributions of ChAT and AChE in budgerigars appeared similar to that in oscine songbirds despite evidence that these systems(More)
Budgerigars throughout life are capable of learning to produce many different sounds including those of human speech. Like humans, budgerigars use multiple craniomotor systems and coordinate both orosensory and auditory feedback in specialized forebrain nuclei. Although budgerigar auditory-vocal learning has a different evolutionary origin from that of(More)
The distribution of iron in the brain of a vocal learning parrot, the budgerigar (Melopsittacus undulatus), was examined using iron histochemistry. In mammals, iron is a highly specific stain for the dorsal and ventral pallidal subdivision as well as specific cell groups in the brainstem, including the substantia nigra pars reticulata [Neuroscience 11(More)
Changes in the cytoarchitecture of vocal control nuclei were investigated in nestling budgerigars (Melopsittacus undulatus) from hatching to fledging (five to six weeks) in relation to changes in vocalizations produced by nestlings during this period. The nuclei investigated were the hypoglossal nucleus, dorsomedial nucleus of the intercollicular midbrain,(More)
In situ hybridization histochemistry was used to assess the effect of auditory stimulation with natural contact calls on expression of NR2A and NR2B NMDA subunit mRNAs in neurons of the thalamic auditory relay nucleus ovoidalis (Ov) of a vocal learning parrot species, the budgerigar (Melopsittacus undulatus). The results showed that both the core (Ov) and(More)
Stimulation with natural contact calls and feeding were used to assess zenk and fos protein expression in budgerigars (Melopsittacus undulatus), a vocal learning parrot species in which feeding and physical contact often occur in conjunction with vocalization. Although only calls induced gene expression in Field L, the primary telencephalic auditory area,(More)