Two distributions of axons in the optic nerve of quails: a study of nerve degeneraron after láser lesions of the retina

Order in the optic pathway has been under cióse scrutiny since the last century. In fishes, the position of the axons along the optic nerve is a function of the position or of the age of the corresponding neu- ronal body in the retina5’12’13. However, in cats, optic axons only show a crude retinotopic order8. Our observations in the quail showed the existence of at least two kinds of axons according to their position in the optic nerve. Although some axons were found in cióse spatial relationship with others originating in the same región of the retina, other axons occupied positions independent of their site of origin in the retina

Laser-Degeneration Study of Nerve Fibers in the Optic Nerve

Knowledge about wiring of neurons is one of the most important goals of neurobiology. Neuronal processes -axons and dendrites- degenerate when they are severed from their cell body. Since different staining procedures distinguish between the degenerating axons and their healthy neighbors, most neuroanatomical pathways have been mapped through the follow-up of degenerating axons after spontaneous or experimental lesions at some point of the pathway. Mapping of neuroanatomical connections has been enormously enriched during the past few years, thanks to new labelling techniques with great resolution power [1]. However, the resolution of the older degeneration procedures is only limited by the extent of the lesion and the resolution of the differential staining of degenerating axons. As we will show in this report, the use of a laser to produce small lesions in the retina of birds, coupled to the detection of degenerating axons in semi-thin plastic sections [2] is allowing us to understand the relationship between axons along the optic pathway with a resolution comparable to that of “in vivo” labelling techniques

Distribution of nerve fibers in the optic nerve of the quail: a laser-degeneration study

Normal visual function requires specific connections between the retina and the visual centers. Connections arise after migration of the optic axons to the brain; however, the biological basis of their specificity are mostly unknown. Som9 of the postulated mechanisms require a recognition between axons and brain neurons, whereas others depend on the maintenance of a retinotopic order along the optic pathways. (P&aacute;rrafo extra&iacute;do a modo de resumen)</em

Posible efecto de los canabinoides endógenos y el rimonabant sobre la insulinorresistencia y la función de las células β

El propósito del trabajo es estudiar el posible papel regulador del sistema canabinoide sobre la secreción de insulina y los cambios endocrino-metabólicos inducidos en ratas normales por una dieta rica en fructosa (DRF).Facultad de Ciencias Médicas (FCM

Distribution of the inositol 1,4,5-trisphosphate receptor, P400, in adult rat brain

The distribution of the inositol 1,4,5-trisphosphate receptor protein, P400, was investigated in adult rat brain by immunocytochemistry with the monoclonal antibody 4C11 raised against mouse cerebellar inositol 1,4,5- trisphosphate receptor protein. Immunoreactive neuronal cell bodies were detected in the cerebral cortex, the claustrum, the endopiriform nucleus, the corpus callosum, the anterior olfactory nuclei, the olfactory tubercle, the nucleus accumbens, the lateral septum, the bed nucleus of the stria terminalis, the hippocampal formation, the dentate gyrus, the caudate- putamen, the fundus striatum, the amygdaloid complex, the thalamus, the caudolateral part of the hypothalamus, the supramammillary nuclei, the substantia nigra, the pedunculopontine tegmental nucleus, the ventrotegmental area, the Purkinje cells in the cerebellum, the dorsal cochlear nucleus, the subnucleus oralis and caudalis of trigeminal nerve, and the dorsal horn of the spinal cord. Immunoreactive fibres were found in the medial forebrain bundle, the globus pallidus, the stria terminalis, the pyramidal tract, the spinal tract of trigeminal nerve, and the ventral horn of spinal cord. Nerve fibres forming a dense plexus ending in terminal-like boutons were detected in relation to nonimmunoreactive neurons of the dentate, interpositus, and fastigial nuclei of the cerebellum and around neurons of the vestibular nuclei. This receptor protein binds a specific second messenger, inositol 1,4,5-trisphosphate, which produces a mobilization of intracellular Ca2+ and a modulation of transmitter release.Peer Reviewe