Cocaine‐ and amphetamine‐regulated transcript peptide (CART) in the brain of zebra finch, Taeniopygia guttata: Organization, interaction with neuropeptide Y, and response to changes in energy status

Abstract

Cocaine- and amphetamine-regulated transcript (CART) has emerged as a potent anorectic agent. CART is widely distributed in the brain of mammals, amphibians, and teleosts, but the relevant information in avian brain is not available. In birds, CART inhibits food intake, whereas neuropeptide Y (NPY), a well-known orexigenic peptide, stimulates it. How these neuropeptides interact in the brain to regulate energy balance is not known. We studied the distribution of CART-immunoreactivity in the brain of zebra finch, Taeniopygia guttata, its interaction with NPY, and their response to dynamic energy states. CART-immunoreactive fibers were found in the subpallium, hypothalamus, midbrain, and brainstem. Conspicuous CART-immunoreactive cells were observed in the bed nucleus of the stria terminalis, hypothalamic paraventricular, supraoptic, dorsomedial, infundibular (IN), lateral hypothalamic, Edinger-Westphal, and parabrachial nuclei. Hypothalamic sections of fed, fasted, and refed animals were immunostained with cFos, NPY, and CART antisera. Fasting dramatically increased cFos- and NPY-immunoreactivity in the IN, followed by rapid reduction by 2 hours and restoration to normal fed levels 6-10 hours after refeeding. CART-immunoreactive fibers in IN showed a significant reduction during fasting and upregulation with refeeding. Within the IN, double immunofluorescence revealed that 94 ± 2.1% of NPY-immunoreactive neurons were contacted by CART-immunoreactive fibers and 96 ± 2.8% NPY-immunoreactive neurons expressed cFos during fasting. Compared to controls, superfused hypothalamic slices of fasted birds treated with CART-peptide showed a significant reduction (P < 0.001) in NPY-immunoreactivity in the IN. As in other vertebrates, CART in the brain of T. guttata may perform several functions, and has a particularly important role in the hypothalamic regulation of energy homeostasis. J. Comp. Neurol. 524:3014-3041, 2016. © 2016 Wiley Periodicals, Inc.

Neuropeptide Y and orexin immunoreactivity in the sparrow brain coincide with seasonal changes in energy balance and steroids

“…The distributions of NPY and OX in song sparrows are consistent with those of other songbirds (Aste et al, ; Boswell, Li, & Takeuchi, ; Boswell, Millam, Li, & Dunn, ; Den Boer‐Visser & Dubbeldam, ; Esposito, Pelagalli, De Girolamo, & Gargiulo, ; Fiore et al, ; Godden et al, ; Gould, Newman, Tricomi, & DeVoogd, ; Miranda et al, ; Phillips‐Singh et al, ; Singh et al, ; Singh et al, ; Singletary et al, , ; Zhou, Murakami, Hasegawa, Yoshizawa, & Sugahara, ). Nonbreeding subjects had higher NPY‐ ir based on IOD measurements than breeding subjects, specifically in the LS, BST, and VTA.…”

Thyrotropin‐releasing hormone (TRH) in the brain and pituitary of the teleost, Clarias batrachus and its role in regulation of hypophysiotropic dopamine neurons

“…For the DAPI‐counterstained photomicrographs, we have pseudocolored the red with green in Abobe Photoshop. The percentage of TH‐immunoreactive neurons in the NPPa contacted by TRH‐immunoreactive axons was calculated as previously described (Singh et al, ). Briefly, sections through the POA from the level of anterior commissure and POR until the paraventricular subdivision of the nucleus preopticus (NPOpv) were selected for image analysis.…”

Regulation of Agouti-Related Protein and Pro-Opiomelanocortin Gene Expression in the Avian Arcuate Nucleus

“…Less is known about CART in birds and its co-expression with POMC has yet to be formally demonstrated. However, immunoreactive CART neuronal cell bodies have been identified in the arcuate nucleus of the zebra finch ( Taeniopygia guttata ) (14). …”