title: Multiple amygdaloid divisions of arcopallium send convergent projections to the nucleus accumbens and neighboring subpallial amygdala regions in the domestic chicken: a selective pathway tracing and reconstruction study.
abstract: Retrograde tracing with choleratoxin B, injected into the nucleus accumbens (Ac) and bed nucleus of stria terminalis, lateral part (BSTL), yielded labeled perikarya in a ring-shaped area of arcopallium, including dorsal and hilar subdivisions, with a wedge-shaped node of dense accumulation in the amygdalopiriform area (APir). Also, the position of source neurons for this arcopallio-subpallial pathway was verified by anterograde tracing. Three subregions of arcopallium (amygdalopiriform, dorsal, hilar) were injected with dextran (10 kDa), and fibers and terminal fields were detected in Ac, BSTL and extended amygdala (EA). Most abundant projections to Ac arose from APir. The study enabled precise description of the main output fiber streams: the dorsal stream follows the dorsal border of arcopallium and, continuing in the ventral amygdalofugal tract, it traverses the EA and the BSTL before reaching the Ac. The ventral stream of fibers enters the EA along the ventral subpallial border and terminates in the basal nucleus and ventral pallidum. The course of the pathway was reconstructed in 3D. Retrogradely labeled arcopallial neurons were devoid of DARPP-32. DARPP-32 was present in the Ac but not the BSTL. No colocalization between the calcium binding proteins calbindin, parvalbumin and calretinin, and retrogradely labeled neurons was detected, despite a considerable territorial overlap. This finding further supports the excitatory nature of the arcopallial-accumbens pathway. Conjoint and convergent amygdalar input to EA, including BSTL, as well as to Ac subregions likely transmits fear and aggression related signals to both viscerolimbic (EA) and learned reward- and motivation-related (Ac) ventrobasal forebrain regions.
authors.affiliation: Department of Anatomy, Histology and Embryology, Faculty of Medicine, Semmelweis University, 58. Tuzolto utca, 1094, Budapest, Hungary.|MTA-SE NAP B Research Group of Experimental Neuroanatomy and Developmental Biology, Hungarian Academy of Sciences, Budapest, Hungary.
authors.forename: János
authors.initials: J
authors.lastname: Hanics
authors.affiliation: Department of Anatomy, Histology and Embryology, Faculty of Medicine, Semmelweis University, 58. Tuzolto utca, 1094, Budapest, Hungary.
authors.forename: Gyöngyi
authors.initials: G
authors.lastname: Teleki
authors.affiliation: Department of Anatomy, Histology and Embryology, Faculty of Medicine, Semmelweis University, 58. Tuzolto utca, 1094, Budapest, Hungary.|MTA-SE NAP B Research Group of Experimental Neuroanatomy and Developmental Biology, Hungarian Academy of Sciences, Budapest, Hungary.
authors.forename: Alán
authors.initials: A
authors.lastname: Alpár
authors.affiliation: Department of Anatomy, Histology and Embryology, Faculty of Medicine, Semmelweis University, 58. Tuzolto utca, 1094, Budapest, Hungary.
authors.forename: Andrea D
authors.initials: AD
authors.lastname: Székely
authors.affiliation: Department of Anatomy, Histology and Embryology, Faculty of Medicine, Semmelweis University, 58. Tuzolto utca, 1094, Budapest, Hungary. csillag@ana.sote.hu.
authors.forename: András
authors.initials: A
authors.lastname: Csillag
mesh_terms: D000679:Amygdala / Q000166:cytology* / Q000378:metabolism; D000818:Animals; D030161:Avian Proteins / Q000378:metabolism; D066187:Basal Forebrain / Q000166:cytology / Q000378:metabolism; D064032:Calbindin 2 / Q000378:metabolism; D064026:Calbindins / Q000378:metabolism; D002645:Chickens; D051937:Dopamine and cAMP-Regulated Phosphoprotein 32 / Q000378:metabolism; D021621:Imaging, Three-Dimensional; D009434:Neural Pathways / Q000166:cytology / Q000378:metabolism; D056347:Neuroanatomical Tract-Tracing Techniques; D009714:Nucleus Accumbens / Q000166:cytology* / Q000378:metabolism; D010320:Parvalbumins / Q000378:metabolism; D016548:Prosencephalon / Q000166:cytology / Q000378:metabolism; D012686:Septal Nuclei / Q000166:cytology / Q000378:metabolism
chemical_list: D030161:Avian Proteins; D064032:Calbindin 2; D064026:Calbindins; D051937:Dopamine and cAMP-Regulated Phosphoprotein 32; D010320:Parvalbumins
keywords: Avian; Basal ganglia; Calcium binding proteins; Dopamine; Subpallium; Viscerolimbic