Organization of the avian basal forebrain: chemical anatomy in the parrot (Melopsittacus undulatus).
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 vocal learning parrot, the budgerigar (Melopsittacus undulatus). Immunological and histological stains, including choline acetyltransferase, acetylcholinesterase, tyrosine hydroxylase, dopamine and cAMP-regulated phosphoprotein (DARPP)-32, the calcium binding proteins calbindin D-28k and parvalbumin, calcitonin gene-related peptide, iron, substance P, methionine enkephalin, nicotinamide adenine dinucleotide phosphotase diaphorase, and arginine vasotocin were used in the present study. We conclude that the ventral paleostriatum (cf. Kitt and Brauth [1981] Neuroscience 6:1551-1566) and adjacent archistriatal regions can be subdivided into several distinct subareas that are chemically comparable to mammalian basal forebrain structures. The nucleus accumbens is histochemically separable into core and shell regions. The nucleus taeniae (TN) is theorized to be homologous to the medial amygdaloid nucleus. The archistriatum pars ventrolateralis (Avl; comparable to the pigeon archistriatum pars dorsalis) is theorized to be a possible homologue of the central amygdaloid nucleus. The TN and Avl are histochemically continuous with the medial aspects of the bed nucleus of the stria terminalis and the ventromedial striatum, forming an avian analogue of the extended amygdala. The apparent counterpart in budgerigars of the mammalian nucleus basalis of Meynert consists of a field of cholinergic neurons spanning the basal forebrain. The budgerigar septal region is theorized to be homologous as a field to the mammalian septum. Our results are discussed with regard to both the evolution of the basal forebrain and its role in vocal learning processes.
Roberts
Todd Freeman
TF
Department of Psychology, University of Maryland, College Park, Maryland 20742, USA. troberts@psyc.umd.edu
Hall
William Sterling
WS
Brauth
Steven Earle
SE
D000110:Acetylcholinesterase / Q000032:analysis; D000679:Amygdala / Q000033:anatomy & histology / Q000737:chemistry; D000818:Animals; D001127:Arginine Vasopressin / Q000032:analysis; D015415:Biomarkers / Q000032:analysis; D064026:Calbindins; D015740:Calcitonin Gene-Related Peptide / Q000032:analysis; D002795:Choline O-Acetyltransferase / Q000032:analysis; D003342:Corpus Striatum / Q000033:anatomy & histology / Q000737:chemistry; D004298:Dopamine / Q000032:analysis; D051937:Dopamine and cAMP-Regulated Phosphoprotein 32; D004744:Enkephalin, Methionine / Q000032:analysis; D007150:Immunohistochemistry; D007501:Iron / Q000032:analysis; D009249:NADP / Q000032:analysis; D009419:Nerve Tissue Proteins; D010311:Parrots; D010320:Parvalbumins / Q000032:analysis; D010750:Phosphoproteins / Q000032:analysis; D016548:Prosencephalon / Q000033:anatomy & histology* / Q000737:chemistry*; D064030:S100 Calcium Binding Protein G / Q000032:analysis; D013373:Substance P / Q000032:analysis; D014446:Tyrosine 3-Monooxygenase / Q000032:analysis; D014828:Vocalization, Animal
D015415:Biomarkers; D064026:Calbindins; D051937:Dopamine and cAMP-Regulated Phosphoprotein 32; D009419:Nerve Tissue Proteins; D010320:Parvalbumins; D010750:Phosphoproteins; D064030:S100 Calcium Binding Protein G; D001127:Arginine Vasopressin; D013373:Substance P; D009249:NADP; D004744:Enkephalin, Methionine; D007501:Iron; D014446:Tyrosine 3-Monooxygenase; D002795:Choline O-Acetyltransferase; D000110:Acetylcholinesterase; D015740:Calcitonin Gene-Related Peptide; D004298:Dopamine