Anatomical distribution of NPY‐like immunoreactivity in the domestic chick brain (Gallus domesticus)

Abstract

Neuropeptide Y-immunoreactive (NPY-ir) fibers and neurons in the brain of the domestic chick (Gallus domesticus) were described using an immunohistochemical technique. NPY-ir neurons were seen in the lobus parolfactorius; hyperstriatum, neostriatum, paleostriatum, and archistriatum; hippocampal and parahippocampal areas; dorsolateral corticoid area; piriform cortex; two thalamic areas contiguous to the n. rotundus; n. dorsolateralis anterior thalami, pars lateralis, and pars magnocellularis; n. periventricularis hypothalami; n. paraventricularis magnocellularis; regio lateralis hypothalami; n. infundibuli; inner zone of the median eminence; dorsal and lateral portions of the n. opticus basalis; n. raphes; and n. reticularis paramedianus. NPY-ir fibers were seen throughout the entire chick brain, but were more abundant in the hypothalamus where they formed networks and pathways. They were also observed in some circumventricular organs. The anatomical data of the present study regarding the distribution of NPY ir in the chick brain, together with the physiological findings of other studies, suggest that NPY plays a key role in the regulation of the neuroendocrine, vegetative, and sensory systems of birds by acting as a neuromodulator and/or neurotransmitter.

Type-dependent differential expression of neuropeptide Y in chicken hypothalamus (Gallus domesticus)

“…This result agrees with previous studies, in which the denser NPY-immunoreactive cell bodies and higher NPY mRNA expression (Esposito et al, 2001;Kameda et al, 2001;Wang et al, 2001) were located, and the higher NPY content was determined in the hypothalamic IN of chickens (Zhou et al, 2005). However, in the meat-type chicken, NPY mRNA level in the PVN was significantly greater than that in the LHA, and was not significantly different between the IN and PVN.…”

“…IN is thought to play a pivotal role in integration of signals regulating appetite (Wang et al, 2001). Neurons in the IN are situated adjacent to the floor of the third ventricle, so they can directly respond to peripheral signals with a reduced brain-blood barrier (Kuenzel et al, 1999;Schwartz et al, 2000;Boswell, 2005) (Aste et al, 1991;Esposito et al, 2001).…”

“…Intracerebroventricular (ICV) administration of NPY in the birds has been found to elicit a marked increase in feeding (Kuenzel et al, 1987;Furuse et al, 1997) and to decrease rectal temperature (Tachibana et al, 2004). On the other hand, dense NPY-like immunoreactivity cells and abundant NPY mRNA expression have been identified in the hypothalamic IN of the domestic chicken (Esposito et al, 2001;Kameda et al, 2001;Wang et al, 2001), and dense NPYimmuno-reactivity fibers, projecting from the IN into the PVN and the LHA were observed (Aste et al, 1991;Boswell et al, 1998;Kameda et al, 2001). Food deprivation or restriction significantly increased feeding behavior, and also elevated messenger ribonucleic acid (mRNA) levels (Boswell et al, 1999), protein contents (Zhou et al, 2005) and neuron activity (Boswell et al, 2002) of the hypothalamic NPY in birds.…”

Neuropeptide Y in the olfactory system, forebrain and pituitary of the teleost, Clarias batrachus

“…Vd in the telencephalon of teleosts corresponds to striatum/basal ganglia of higher vertebrates (Reiner and Northcutt, 1992). NPY immunoreactive cells were described in the corresponding areas in mammals (de Quidt and Emson, 1986), birds (Anderson and Reiner, 1990;Esposito et al, 2001), reptiles (Medina et al, 1992;Bennis et al, 2001) and amphibians (Tuinhof et al, 1993;Ebersole et al, 2001).…”

Expression of agouti-related protein (AgRP) in the hypothalamus and adrenal gland of the duck (Anas platyrhynchos)

“…The avian homologue of the arcuate nucleus, the tuberal hypothalamus (infundibular neurones) , contains AgRP cells and/or NPY-producing cells in several avian species (Kuenzel and McMurtry 1988;Boswell et al 2002;Strader and Buntin 2001;Strader et al 2003;Esposito et al 2001). To date, AgRP immunoreactivity has been shown only in the tuberal and lateral hypothalamic regions of the ring dove Buntin 2001, Strader et al 2003).…”