Topological and histological description of preoptic area and hypothalamus in cardinal tetra Paracheirodon axelrodi (Characiformes: Characidae)

Abstract

Topological and histological descriptions of the preoptic area and hypothalamus of the cardinal tetra Paracheirodon axelrodi were performed. Standard histological paraffin sections were used and stained with Nissl technique, and plastic sections for high-resolution optic microscopy (HROM). The preoptic area showed some differences related to the location of the magnocellular preoptic nucleus (PM) and the size of the neurons in this region, as they were the biggest in all the preoptic area. Additionally, within the preoptic area, the different structures that comprise the organum vasculosum of the lamina terminalis (OVLT) were identified and characterized. The hypothalamus could be subdivided in three regions -the ventral, the dorsal and the caudal hypothalamic regions -neuron morphology, size and staining pattern were similar in all of them.Keywords: Brain, High resolution optic microscopy (HROM), Organum vasculosum of the lamina terminalis (OVLT).Se realizó la descripción topológica e histológica del área preóptica e hipotálamo en el Neón cardenal Paracheirodon axelrodi. Se usaron cortes obtenidos con tecnicas histológicas estándar, coloreados con técnica de Nissl y secciones en resina con microscopía óptica de alta resolución (MOAR). El área preóptica muestra algunas diferencias relacionadas con la localización del núcleo preóptico magnocelular (PM) y el tamaño de algunas neuronas en esta región, puesto que estas eran las más grandes de toda el área preoptica. Adicionalmente, dentro del área preóptica, fue posible identificar y caracterizar las diferentes estructuras que componen el órgano vasculoso de la lámina media (OVLM). El hipotálamo puede sudividirse en tres zonas: la zona hipotalámica ventral, la zona hipotalámica dorsal y la zona hipotalámica caudal. La morfología de las neuronas de los núcleos que comprenden las diferentes zonas del hipotálamo tiene tamaño, forma y coloración similar.Palabras Clave: Cerebro, Microscopía óptica de alta resolucion (MOAR), Órgano vasculoso de la lámina terminal (OVLT).

Glyphosate commercial formulation effects on preoptic area and hypothalamus of Cardinal Neon Paracheirodon axelrodi (Characiformes: Characidae)

“…No morphological alteration of AP and HT was observed after Roundup Activo™ treatments. AP, PDR and HT staining and distribution are similar to other teleost species (Rincón et al, 2017).…”

“…Preoptic area and hyphothalamus present several neuronal nuclei as described for P. axelrodi (Obando et al, 2013;Rincón et al, 2017), similar to other teleost species like D. rerio and Carassius auratus (Linnaeus, 1758) (Fryer, Maler, 1981;Wullimann et al, 1996). Neurons form preoptic area usually have round nuclei, scarce cytoplasm.…”

“…After dehydration, tissues were embedded in Poly/ Bed®812-propylen oxide 1:2 and 1:1, with a final 100% Poli/Bed®812. Samples were polymerized at 60°C (Obando et al, 2013;Rincón et al, 2017). Sections were obtained with Microm Slee Cut 40650 rotatory microtome and stained with toluidine blue (Obando et al, 2013;Rincón et al, 2017).…”

“…Samples were polymerized at 60°C (Obando et al, 2013;Rincón et al, 2017). Sections were obtained with Microm Slee Cut 40650 rotatory microtome and stained with toluidine blue (Obando et al, 2013;Rincón et al, 2017). Photographs were examined in the microscope Zeiss Axio Scope A1 coupled to a Zeiss Axiocam ICM 1 camera.…”

Evolution of the Hypothalamus and Inferior Lobe in Ray-Finned Fishes

“…Little is known about the morphology and evolution of the hypothalamus in ray-finned fishes. The hypothalamus of teleosts is located in the ventral part of the brain and bordered rostrally by the preoptic area, dorsocaudally by the posterior tuberculum, and ventrally by the hypophysis [Braford and Northcutt, 1983;Fernald and Shelton, 1985;Gómez-Segade and Anadón, 1988;Striedter, 1990a;Butler and Northcutt, 1993;Cerdá-Reverter et al, 2001;Ou and Yamamoto, 2016;Rincón et al, 2017]. Three main regions constitute the hypothalamus in teleosts: the periventricular portion, tuberal lobe, and inferior lobes [Braford and Northcutt, 1983;Fernald and Shelton, 1985;Gómez-Segade and Anadón, 1988;Striedter, 1990a;Cerdá-Reverter et al, 2001].…”