Localization of dopamine D1 receptors and dopaminoceptive neurons in the chick forebrain

Abstract

The distributions of dopamine D1 receptors, dopaminoceptive neurons, and catecholaminergic fibers were investigated in the forebrain of the domestic chick by using D1 receptor autoradiography and immunohistochemical detection of D1 receptor protein (D1rp), the dopamine- and cAMP-regulated phosphoprotein DARPP-32, and tyrosine hydroxylase (TH). Particular attention was paid to two forebrain regions, the mediorostral neostriatum/ hyperstriatum ventrale (MNH) and neostriatum dorsocaudale (Ndc), which have been shown to be crucially involved in filial imprinting. In general, there was a good, but not complete, correlation between the immunohistochemical pattern of DARPP-32 positive perikarya and the distribution of D1 receptors. Both, DARPP-32 positive neurons as well as D1 receptors were highly enriched in the striatal part of the basal ganglia including the lobus parolfactorius (LPO) and paleostriatum augmentatum. High to moderate densities were observed in the outer rind of the pallium. Low to moderate densities were found in the belt regions of primary sensory areas, whereas densities in the respective core regions were generally low. Labeling in the MNH and Ndc was heterogeneous. Whereas the neostriatal part of MNH displayed both, moderate DARPP-32 immunostaining and moderate D1 receptor densities, the hyperstriatal part showed also moderate D1 receptor densities but was only weakly labeled by DARPP-32. The rostral part of the Ndc was among the most intensely DARPP-32 labeled areas of the pallium, its caudal part revealed only moderate DARPP-32 immunostaining. By using D1 receptor autoradiography, a homogeneous labeling throughout the rostrocaudal extension of the Ndc was found. Double-labeling experiments with antibodies to DARPP-32 and TH revealed that TH positive fibers in the MNH, Ndc, and LPO were often closely related to DARPP-32 positive perikarya. At the ultrastructural level, both immunoreaction for D1rp and DARPP-32 in the MNH and Ndc were primarily found to be associated with postsynaptic elements. Whereas D1rp immunoreactivity was enriched at postsynaptic densities or in their vicinity, reaction product for DARPP-32 was present throughout the perikaryal cytoplasm, dendrites, and dendritic spines. These results indicate that DARPP-32 as well as D1 receptors in the avian forebrain reveal a distribution that is substantially similar to that of mammals.

Revised nomenclature for avian telencephalon and some related brainstem nuclei

“…Although Karten and Dubbeldam (1973) thought that its position resembled that of the mammalian internal pallidal segment, subsequent immunolabeling studies showed that it lacked the pallidal-type neurons and the SP/DYNcontaining striatal input characteristic of the internal pallidal segment Reiner and Carraway, 1987;Anderson and Reiner, 1990;Veenman and Reiner, 1994). More recent studies have shown that the INP contains spiny neurons that express DARPP32, a striatal characteristic (Schnabel et al, 1997;Reiner et al, 1998b), a very similar glutamate receptor profile to the striatum (Wada et al, 2001), and numerous cholinergic neurons , which is characteristic of, but not unique to, the striatum. Moreover, the INP has recently been found to develop within the striatal sector of the subpallium, to show continuity with the medial striatum, and to contain neurons expressing cell-surface proteins characteristic of striatal neurons .…”

Out of Context: NMDA Receptor Antagonism in the Avian 'Prefrontal Cortex' Impairs Context Processing in a Conditional Discrimination Task.

“…This conclusion rests on a large data set involving neuroanatomical, physiological, neurochemical, and behavioral results. Neuroanatomical studies showed the NCL to receive multimodal input from all secondary sensory areas of the forebrain (Leutgeb, Husband, Riters, Shimizu, & Bingman, 1996), to project to telencephalic motor output structures as well as to the basal ganglia (Kröner and Güntürkün, 1999), to be innervated by dopaminergic fibers from midbrain cell groups A8 -A10 (Metzger, Jiang, Wang, & Braun, 1996), and to be characterized by a high density of dopamine D 1 receptors (Schnabel et al, 1997). Physiological studies demonstrated that single units in the NCL code for the upcoming reward (Kalt, Diekamp, & Güntürkün, 1999), bridge the delay between stimulus and response by high sustained activity levels (Diekamp, Kalt, & Güntürkün, 2002), and code for the subjective reward value of a reinforcer (Kalenscher et al, 2005).…”

Distribuição de receptores ionotrópicos de glutamato e sua co-localização com a fosfoproteína neural DARPP-32 no córtex pré-frontal de ratos.

“…3), incluindo receptores de neurotransmissores, canais e bombas iônicas, além de fatores transcripcionais GREENGARD, 2001;SVENNINGSSON et al, 2004). A distribuição da DARPP-32 foi estudada através de técnicas de imunohistoquímica no cérebro de ratos (OUIMET e GREENGARD, 1990a, b), primatas (BERGER et al, 1990;OUIMET et al, 1992), e aves (SCHNABEL et al, 1997). Em todas as espécies examinadas, a DARPP-32 foi demonstrada estar enriquecida nas regiões do cérebro que receberam densas aferências dopaminérgicas e em particular em regiões contendo receptores do tipo D1.…”