The avian arcopallium/amygdala complex is the abyss of neuroanatomists. You think that the mammalian amygdala is complex? Then come and see the bird version. Here, a bewildering number of limbic (amygdala) and premotor (arcopallium) subnuclei are interwoven on smallest conceivable space. Neuroanatomists from Düsseldorf and biopsychologists from Bochum now took the challenge to map this area by a painstaking quantitative analysis of 12 different transmitter receptor binding sites, combined with a detailed analysis of the cyto- and myelo-architecture. Their approach not only revealed newly discovered subregions but also resulted in a novel map of this most complex area of the bird pallium and striatum. After having accomplished this, the scientists compare the receptor architecture of the subregions to their possible mammalian counterparts and come to a novel interpretation of many of the scrutinized subregions.

Herold, C., Paulitschek, C., Palomero-Gallagher, N., Güntürkün, O. and Zilles, K. Transmitter receptors reveal segregation of the arcopallium / amygdala complex in pigeons (Columba livia), J. Comp. Neurol., 2018, 526: 439–466.