Distribution of cocaine- and amphetamine-regulated transcript (CART), neuropeptide Y (NPY) and galanin (GAL) in the pterygopalatine ganglion of the domestic duck (Anas platyrhynchos f. domestica)

Abstract

Introduction. Cocaine-and amphetamine-regulated transcript (CART), neuropeptide Y (NPY) and galanin (GAL) act as neurotransmitters and neuromodulators in both the central and peripheral nervous systems. Their presence has been found in different taxonomic groups, in particular in mammals. However, only few investigators have studied these neuropeptides in the class Aves (birds). The aim of the present study was to describe the distribution of CART, NPY and GAL in the pterygopalatine ganglion (PPG) of the domestic duck (Anas platyrhynchos f. domestica). Material and methods. The experiment was conducted on 16 one-year-old domestic ducks of the Pekin breed of both sexes (8 males and 8 females). Frozen sections of the PPG were subjected to immunofluorescence staining using primary mouse monoclonal antibodies directed against CART and GAL and rabbit polyclonal antibody directed against NPY. Secondary antibodies were conjugated with Cy3 and FITC fluorochromes. Results. CART, NPY, and GAL were present in the PPG of the domestic duck. The highest immunoreactivity (IR) in the ganglionic cells was found for CART in the majority (83-85%) of neurons of both superior (SPPG) and inferior (IPPG) PPG. CART-IR was also found in small aggregations of neurons on the medial surface of the Harderian gland, and on the course of the palatine branch of the facial nerve. CART-IR was also observed in the nerve fibers of these neurons' aggregations; however, it was low in comparison to the immunoreactivity of the perikarya. Immunoreactivity of NPY was found in ganglionic neurons, but above all in numerous fibers of the SPPG and IPPG and within aggregations on the surface of the Harderian gland. NPY-IR cells were distributed irregularly over the cross-sections of the tested aggregations, and constituted from 36% to 43% of the SPPG and from 37% to 40% of the IPPG of all cross-sectioned neurons. GAL-immunoreactive perikarya, distributed irregularly across the sections, were observed in the SPPG, where they constituted 61-65%, and in the IPPG, where they made up 50-57% of all neurons. All immunoreactive neurons were characterized by immunopositive neuroplasm and immunonegative cell nuclei.

An Immunohistochemical Study of Cocaine- and Amphetamine-Regulated Transcript (Cart) Expression in the Pterygopalatine Ganglion of the Pig

“…Noteworthy, in the latter study no presence of CART-IR nerve terminals forming pericellular baskets around intracardiac neurons were found. Similarly to our fi ndings, the presence of low density CART-IR nerve plexus between PPG ganglionic neurons was recognized in the duck [13], whereas no such kind of data has been presented in relation to the rat's PPG. Taking into account the above, it is possible, that in particular porcine PPG ganglia CART-IR nerve terminals may originate from CART-positive central neurons and/or other PPG CART-IR ganglionic neurons.…”

“…These fi ndings are, in general, in line with the results of previous studies as Ivanusic et al [12] have immunohistochemically determined that as many as 5.25% of the rat sphenopalatine ganglionic neurons express CART. Although no direct correlation to mammals could be easily given it is worth to mention that in the duck, the expression of CART in neurons of both superior and inferior PPG was relatively very high and amounted to 83-85% [13]. The outlined differences between the proportions of CART-ergic neurons in the mammalian and avian PPG suggest the presence of species-related differences.…”

“…Besides, major neurotransmitter PPG neurons also express various neuropeptide receptors [8] as well as a bulk of neuroactive peptides acting as neuromodulators and/or co-transmitters [9][10][11]. Recently, the presence of novel multipotent neuropeptide cocaine-and amphetamineregulated transcript (CART) has been found in a small subset of the rat's [12] and the duck's [13] PPG neurons, however the full meaning of this fi nding is still obscure. Numerous observations clearly showed that CART widely expressed throughout the central nervous system has been implicated in a variety of functions including feeding and food intake, stress, reward and reinforcement and many more (for recent review see [14]).…”

Distribution and variation of neuropeptide Y in the brain of native Thai chicken

“…These results correspond with previous reports in several avian species such as chickens, 17,18,27 quails, 28 pigeons, 29,30 collared doves, 31 black-capped chickadees ( Parus atricapillus ), blue tits ( Parus caeruleus ), great tits ( Parus major ), dark-eyed juncos ( Junco hyemalis , Gould et al 32 ), and domestic ducks. 33 However, there are at least some species differences; for example, NPY-ir fiber was not observed within the PHN, PVN, and IN of quail brains. 28…”

“…The distributions of NPY neurons and its mRNA expression in the brain of several avian species have been investigated, including chickens, 18,20,26,27 quails, 26,28 pigeons, 29,30 collared doves, 31 black-capped chickadees ( Parus atricapillus ), blue tits ( Parus caeruleus ), great tits ( Parus major ), dark-eyed juncos ( Junco hyemalis , Gould et al 32 ), and domestic ducks. 33 The arcuate nucleus (ARC) plays a role in NPY-induced food intake in mammals, in which the PVN is thought to be one of the major targets of NPY releasing neurons in the ARC. 34 In birds, the infundibular nucleus (nucleus infundibuli hypothalami, IN) may play a role similar to that of mammalian ARC.…”