RESUMEN
Co-expression of tyrosine hydroxylase (TH) and neuropeptide Y (NPY) in local circuits innervating the hypothalamo-pituitary complex of the green frog, Rana ridibunda, was investigated using simultaneous double immunohistochemical technique, aided by dual-channel confocal laser scanning microscopy. NPY and TH immunoreactivities were observed co-occurring within a discrete neuronal population located in the suprachiasmatic region. In other hypothalamic areas, NPY-immunoreactive (IR) perikarya were generally codistributed, but distinct from TH-IR cells. In the adenohypophysial pars intermedia, the overlap between the two markers was partial, demonstrating the existence of multiple neuronal sources for the inputs to the gland.
Asunto(s)
Sistema Hipotálamo-Hipofisario/química , Neuropéptido Y/análisis , Tirosina 3-Monooxigenasa/análisis , Animales , Femenino , Técnica del Anticuerpo Fluorescente , Sistema Hipotálamo-Hipofisario/citología , Masculino , Microscopía Confocal , Fibras Nerviosas/química , Neuronas/química , Rana ridibundaRESUMEN
We studied the co-occurrence of substance P-(SP) and leucine (or methionine) enkephalin (ENK)-like immunoreactivities in the prosencephalon of two amphibians: Rana esculenta L. (Anura) and Triturus carnifex Laur. (Urodela) using single and double immunohistochemical methods. The two peptides (SP-ENK) were sometimes found colocalized in neuronal cell bodies and processes. Double-labelled neurons were seen in the nucleus accumbens, lateral septal nucleus, preoptic area, dorsal and ventral hypothalamic nuclei of the frog, whereas in the newt co-occurrence was shown in neurons of the primordium pyriform, corpus striatum, pars ventralis thalami, preoptic area and nucleus infundibularis dorsalis and ventralis. Furthermore, in both amphibians, fibres simultaneously showing SP- and ENK-positivity were observed in the amygdaloid complex, preoptic area and in the posterior hypothalamus, around the infundibulum. Co-occurrence studies in comparative neuroanatomy are relevant, as shown in the present paper regarding the similarities of SP-ENK distribution in the striatopallidal and striatonigral systems of tetrapods.
Asunto(s)
Encefalinas/análisis , Prosencéfalo/química , Rana esculenta/metabolismo , Sustancia P/análisis , Triturus/metabolismo , Animales , Femenino , Técnica del Anticuerpo Fluorescente , MasculinoRESUMEN
The pattern of distribution of carnosine-like immunoreactivity and its relation to glial fibrillary acidic protein immunoreactivity have been studied in two lizards (Gallotia galloti and Tarentola delalandii) and in two anuran amphibians (Rana esculenta and Xenopus laevis) using immunocytochemical techniques. Biochemical data obtained by paper electrophoresis show that the dipeptides carnosine and homocarnosine are both present in the brain of all the species examined. In the central nervous system of both anurans and reptilians, carnosine immunoreactivity is localized in glial cells. An important species difference is, however, seen in the olfactory system since primary olfactory neurons and their processes extending to the olfactory bulb are carnosine positive in reptiles, whereas they are not immunostained in anurans. Thus, the cellular distribution of carnosine immunoreactivity in reptilians is very similar to that observed in birds and mammals and is distinct from that seen in amphibia.
Asunto(s)
Química Encefálica , Carnosina/análisis , Lagartos/metabolismo , Neuroglía/química , Bulbo Olfatorio/química , Rana esculenta/metabolismo , Xenopus laevis/metabolismo , Animales , Carnosina/análogos & derivados , Femenino , Proteína Ácida Fibrilar de la Glía/análisis , Masculino , Neuronas/química , Especificidad de la EspecieRESUMEN
The distribution of calcitonin gene-related peptide (CGRP) has been investigated in the hypothalamus of the frog Rana esculenta L. by means of different immunohistochemical techniques. A few immunopositive cell bodies and several fibers have been demonstrated in the preoptic area and in the caudal hypothalamus. Some CGRP-like fibers were also recognized in the outer zone of the median eminence. Simultaneous double immunofluorescence methods showed CGRP-like immunoreactivity to be often contiguous to substance P-like positive structures, but separated from them.
Asunto(s)
Péptido Relacionado con Gen de Calcitonina/análisis , Hipotálamo/química , Hipófisis/química , Rana esculenta/metabolismo , Animales , Técnica del Anticuerpo Fluorescente , Inmunohistoquímica , Eminencia Media/química , Fibras Nerviosas/química , Neuronas/química , Área Preóptica/química , Sustancia P/análisisRESUMEN
Three rabbit polyclonal antisera, originally developed against neuromedin B and highly selective against ranatensin subfamily molecules, were used to study the distribution of neuromedin B-like immunoreactivity in the brain of Rana esculenta. Immunopositive cell bodies were observed in several brain regions, including medial and lateral septal nuclei, nucleus of the diagonal band of Broca, medial amygdala, ventral striatum, ventromedial and posterior thalamic nuclei, nucleus of the periventricular organ, posterior tuberculum, dorsal, lateral and ventral hypothalamic nuclei, optic tectum, mesencephalic tegmentum and central rhomboencephalic gray. A dense network of immunopositive fibers was also distributed in defined regions of the frog brain, i.e. in the medial pallium, septum, amygdala, ventral thalamus, preoptic area and posterior hypothalamus. The results of the present study, taken with available molecular biology data, indicate that the naturally occurring antigen is probably represented by a ranatensin/litorin-related antigen.
Asunto(s)
Química Encefálica/fisiología , Neuroquinina B/análogos & derivados , Rana esculenta/metabolismo , Animales , Diencéfalo/química , Femenino , Inmunohistoquímica , Masculino , Mesencéfalo/química , Fibras Nerviosas/química , Neuroquinina B/análisis , Neuronas/química , Rombencéfalo/química , Telencéfalo/químicaRESUMEN
The distribution of the dipeptide carnosine was studied in the brain of the crested newt, Triturus carnifex, with immunohistochemical methods. Carnosine-like immunoreactivity (IR) is present in the cell bodies and processes of several areas of the central nervous system: in the telencephalon (especially in the medial pallium), in the diencephalon (pineal organ, thalamus, and hypothalamus), in the mesencephalon (optic tectum and tegmentum), and in the rhombencephalon (cerebellum, raphe region, and octavolateralis area). Double-labelling experiments show that carnosine IR is colocalized with tyrosine hydroxylase and neuropeptide Y IR in a few cells. Histochemical staining for heavy metals, the TIMM method, reveals that carnosine IR and TIMM labelling overlap in the medial pallium. These data indicate two primary conclusions: (a) In the crested newt brain, in contrast to those of mammals and birds, carnosine IR is not associated with glial cells but with neurons. Furthermore, carnosine is absent from the primary olfactory pathway in newts. (b) In the medial pallium of the crested newt, carnosine IR reliably identifies a population of neurons.
Asunto(s)
Carnosina/metabolismo , Salamandridae/anatomía & histología , Animales , Mapeo Encefálico , Femenino , Técnica del Anticuerpo Fluorescente , Masculino , Neuronas/ultraestructura , Médula Espinal/anatomía & histologíaRESUMEN
We report the effects of olfactory peripheral deafferentation by intranasal irrigation with ZnSO4 on carnosine and CGRP immunoreactivities in the mouse olfactory system. In the normal rodent olfactory epithelium carnosine immunoreactivity is associated with the olfactory receptor neurons. Conversely, CGRP immunoreactivity appears to be associated with the trigeminal innervation of the nasal cavity. Following lesion the magnitude of carnosine immunoreactivity in the olfactory epithelium is strongly reduced while CGRP immunoreactivity is unaffected. In the olfactory bulb, deafferentation causes a strong reduction of carnosine immunoreactivity in the glomerular layer and, concurrently, of TH immunoreactivity in the juxtaglomerular neurons. CGRP immunoreactive fibers in the olfactory bulb are abundant in the glomerular layer both before and after deafferentation. These data demonstrate that, in the adult mouse, the immunocytochemically detectable levels of CGRP are not altered following lesion and indicate CGRP is not released directly from the olfactory neurons to induce TH production.
Asunto(s)
Péptido Relacionado con Gen de Calcitonina/análisis , Carnosina/análisis , Bulbo Olfatorio/química , Nervio Olfatorio/fisiología , Tirosina 3-Monooxigenasa/análisis , Animales , Desnervación , Epitelio/química , Femenino , Técnicas para Inmunoenzimas , RatonesRESUMEN
The distribution of acetylcholinesterase and of two neuropeptide (substance P and calcitonin gene-related peptide) immunoreactivities has been investigated in sensory neurons of lumbosacral dorsal root ganglia during chick embryo development, combining immunolocalization of neuropeptides with simultaneous histochemical detection of acetylcholinesterase, in order to study co-localization of the two peptides and their relations with acetylcholinesterase. Acetylcholinesterase at E7 of development appears in only a few neurons, usually the larger ones located in the lateroventral region of the ganglia. As development proceeds the number of neurons and intensity of staining increase. Until E12-13 acetylcholinesterase positivity is limited to the region of the ganglion containing larger neurons. At later stages (E20) it spreads progressively, leading to staining of cells over the whole ganglion. Substance P-like immunoreactivity appears at E6 and for calcitonin gene-related peptide at E7. These immunoreactivities progressively increase with development, remaining limited to the small neuron compartment of the dorsomedial region of the ganglion. Immunoreactivity for both neuropeptides reaches a maximum around E10-13 and then declines. Using simultaneous double immunostaining, calcitonin gene-related peptide and substance P-like immunoreactivities are largely co-localized, although their distribution is not completely coincident. Neuropeptide-positive cells are usually devoid of any acetylcholinesterase activity until E15. They become positive for the enzyme at later stages. The significance of acetylcholinesterase expression in sensory neurons and the possible relation of its appearance and neuron size is discussed.
Asunto(s)
Acetilcolinesterasa/metabolismo , Péptido Relacionado con Gen de Calcitonina/metabolismo , Desarrollo Embrionario y Fetal , Ganglios Espinales/metabolismo , Sustancia P/metabolismo , Acetilcolinesterasa/fisiología , Animales , Péptido Relacionado con Gen de Calcitonina/fisiología , Embrión de Pollo , Ganglios Espinales/citología , Ganglios Espinales/embriología , Inmunohistoquímica , Sustancia P/fisiologíaRESUMEN
The localization of substance P (SP) and calcitonin gene-related peptide (CGRP) was studied in the untreated spinal cord of the frog using single or double immunohistochemical stainings. SP and CGRP appear to coexist in the primary afferent fibers and in the marginal and submarginal dorsal horn zones, as well as in the dorsolateral zone. In other parts of the spinal cord CGRP immunoreactivity was scanty while diffuse SP systems were seen, suggesting that the coexistence of the two peptides is restricted to primary afferent fibers.