Immunohistochemical localization of cocaine‐ and amphetamine‐regulated transcript peptide in the central nervous system of the frog Rana esculenta

Abstract

The distribution of cocaine- and amphetamine-regulated transcript peptide (CARTp)- like immunoreactivity was studied only in the rat central nervous system (CNS). In mammals, CART peptides occur among others in brain areas that control feeding behavior. We mapped CARTp-immunoreactive structures in the CNS of the frog Rana esculenta and assumed that differences may exist in the CARTp-containing neuronal populations between the frog, which does not feed in winter, and the rat. In the forebrain, immunoreactive cells and fibers were found in the olfactory bulb, nucleus accumbens, amygdala, medial pallium, septum, striatum, the preoptic nuclei, ventromedial nucleus, central thalamic nucleus, and the hypothalamus. The optic pathway was free of immunoreactivity. The neurohypophysis showed intense immunostaining. In the mesencephalon, many cells were stained in the Edinger-Westphal nucleus, and a few in the optic tectum, where fibers were stained in all plexiform layers. In the retina, some cells in the inner nuclear layer contained CARTp. In the rhombencephalon, cells were stained in the raphe nuclei, central gray, nucleus of the solitary tract, and the vicinity of motor nuclei. Neurons of the motor cranial nerves were densely innervated by CARTp-positive fibers originating from the spinal cord. In the spinal cord, preganglionic cells were stained, and motoneurons were surrounded by immunoreactive varicose axon terminals. Major differences were found between the frog and the rat brains in the distribution of CARTp in the visual system, olfactory bulb, preoptic area, and the motor nuclei. Some of these differences may be related to feeding behavior of these animals.

Distribution and chemical coding pattern of the cocaine- and amphetamine-regulated transcript (CART) immunoreactivity in the preoptic area of the pig

“…A lower expression of CART characterizes the porcine LPA and the MPN. Generally, porcine CART distribution is similar to the distribution described in previous studies in rats [20], humans [32] and lower vertebrates [30][31]. It is very difficult to precisely compare the distribution of CART in the porcine POA with the distribution in other species because there are only a few papers that deal with this issue and the division of the preoptic area differs in each species.…”

“…The low CART-immunoreactivity of the neurons in the preoptic area of the pig and in other animals that have been studied [31,32], and the very rich CART innervation of the region may suggest that most CART-IR fibers are extrinsic in nature. It should also be noted that the animals in our studies were not injected with colchicine.…”

“…In lower vertebrates, the general CART-immunoreactivity of the preoptic area is also similar to that described above. For example, in the frog, a large number of immunoreactive grains and fine varicose fiber terminals occupied the whole preoptic area and only a few CART-IR cells were observed [31]. In the catfish, most CART fibers were located in the lateral portion of the preoptic area with some CART-IR neurons in the preoptic periventricular nucleus [30].…”

“…This area is reciprocally strictly connected with many hypothalamic nuclei [22][23][24], and it influences behavioral, neuroendocrine, and autonomic nervous system activity associated with reproduction, controlling male sexual behavior [25][26][27], regulating the cyclic release of pituitary gonadotropins [28] and helping regulate parental behavior [29]. There are only a few papers concerning CART peptide occurrence in the preoptic area [30][31][32] and the neuroanatomical distribution of CART and its chemical coding in the preoptic area has not been studied in detail.…”

Effect of starvation on Fos and neuropeptide immunoreactivities in the brain and pituitary gland of Xenopus laevis

“…The highly speciWc rabbit anti-Xenopus CRF (xCRF; dilution: 1:15) (Boorse and Denver, 2004;Calle et al, 2005a;Yao et al, 2004), rabbit anti-rat Ucn1 (1:30,000) (Bittencourt et al, 1999;Kozicz et al, 2002), rabbit antibovine ENK (1:1000) (Calle et al, 2005b) and rabbit anti-Xenopus NPY (xNPY; 1:8000) (Tuinhof et al, 1994;Ubink et al, 1997) sera had been used in our laboratories before. The C6-1 F4D4 CART-antiserum (1:100,000) had been raised in mice against the 109-126 fragment of rat CART peptide (Koylu et al, 1997;Lázár et al, 2004).…”