Terminales nerviosas sensitivas en los planos extensores de los dedos de la mano / Sensitive nerve terminations in the extensor layers of the fingers

En este trabajo se describe el hallazgo de terminales nerviosas sensitivas en los planos histologicos que subyacen al aparato extensor digital de la mano. Cuarenta y ocho preparados frescos de sujetos cadavericos fueron teñidos con hemotoxilina-eosina, con tricromico de Mason y con impregnacion argentica para reticulina. Las coloraciones permitieron diferenciar y mostrar las estirpes celulares y las variedades tisulares de diferentes planos que se corresponden con los descritos en otro trabajo publicado, relacionados con la aponeurosis extensora digital subtendinosa y las fascias preperiosticas falangicas dorsales, asi fue posible constatar la presencia de fibras colagenas en los tejidos correspondientes al capuchon extensor, la caracteristica abundancia de fibras reticulares a lo largo de todos los planos observados, el aspecto y el contenido tipicos de los adipocitos, y la presencia de elementos nerviosos, tales como corpusculos receptores de Pacini en la fascia preperiostica falangica dorsal

Estructura histologica de los planos subyacentes al aparato extensor de los dedos de la mano / Histological structure of the planes underlying the fingers extensor apparatus

En este trabajo se muestra la composicion microscopica de dos planos anatomicos que discurren en profundidad al aparato extensor digital de la mano humana, revelandose la aponeurosis extensora digital subtendinosa compuesta por tejido conectivo denso y por un tejido conectivo laxo con componentes de tejido adiposo unilocular las fascias preperiosticas falangicas dorsales. Se procedio a la observacion de preparados histologicos provenientes de 48 preparados frescos de sujetos cadavericos adultos y fetales teñidos con hematoxilina-eosina, tricromico de Masson e impregnacion argentica para fibras de reticulina. Las diferentes coloraciones utilizadas permitieron diferenciar y mostrar las estirpes celulares y las variedades tisulares que se revelaron al microscopio; asi fue posible constatar la presencia de fibras colagenas en los tejidos correspondientes al capuchon extensor; la caracteristica abundancia de fibras reticulares rodeando vasos y nervios; el aspecto y el contenido tipicos de los adipositos; y la presencia de elementos nerviosos, como corpusculos receptores. La presencia de estos tejidos entre el aparato extensor y el periostio permite inferir que sus funciones contribuyen al normal deslizamiento del primero sobre el ultimo. Ademas, la integridad anatomica de estos planos evita las adherencias entre el tendon extensor y el periostio, tanto en condiciones normales como luego de heridas o intervenciones quirurgicas

Distribution of NADPH-diaphorase in rat mesencephalon: a light and electron microscopical study.

NADPH-diaphorase is a useful technique to reveal NO producing neurons at light microscopic level (LM). A modification of the technique using the tetrazolium salt BSPT as substrate, is useful to study the ultrastructure of NO neurons. The aim of this work was to perform a detailed analysis of NADPH-diaphorase reactive neurons in rat mesencephalon both at light and electron microscopic levels. NADPH-diaphorase reactive neurons were observed in superior colliculus, in central gray matter, in dorsal and medial raphe and in the pedunculopontine tegmental nucleus using two histochemical techniques at LM. Electron microscopy showed deposits on membranes of the endoplasmic reticulum, Golgi apparatus and nuclear envelope of dorsal raphe neurons. Presynaptic and postsynaptic terminals showed deposits on membranous elements but postsynaptic terminals also showed deposits on the inner surface of their membranes. Further physiological studies are needed to clarify the meaning of the ultrastructural findings such as the putative interaction of NOS with postsynaptic proteins, receptors or membranous channels.

Distribution of NADPH-diaphorase in rat mesencephalon: a light and electron microscopical study

NADPH-diaphorase is a useful technique to reveal NO producing neurons at light microscopic level (LM). A modification of the technique using the tetrazolium salt BSPT as substrate, is useful to study the ultrastructure of NO neurons. The aim of this work was to perform a detailed analysis of NADPH-diaphorase reactive neurons in rat mesencephalon both at light and electron microscopic levels. NADPH-diaphorase reactive neurons were observed in superior colliculus, in central gray matter, in dorsal and medial raphe and in the pedunculopontine tegmental nucleus using two histochemical techniques at LM. Electron microscopy showed deposits on membranes of the endoplasmic reticulum, Golgi apparatus and nuclear envelope of dorsal raphe neurons. Presynaptic and postsynaptic terminals showed deposits on membranous elements but postsynaptic terminals also showed deposits on the inner surface of their membranes. Further physiological studies are needed to clarify the meaning of the ultrastructural findings such as the putative interaction of NOS with postsynaptic proteins, receptors or membranous channels.(AU)

Striatal cytomegalic neurons containing nitric oxide are associated with experimental perinatal asphyxia: implication of cold treatment

Neuropathological mechanisms triggered by excitatory aminoacids are Known to involve nitric oxide (NO). Neurons containing NO are histochemically reactive to nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d), which labels NO synthase in CNS, Sprague-Dawley male rats subjected to perinatal asphyxia (PA) at 37 degreese Celsius, and PA plus 15 degreese Celsius hypothermia were evaluted when 6 months old by NADPH-d histochemical reaction. Computarized image analysis was used for quantification of stained sections. NADPH-d neurons in striatum from subsevere and severe PA showed a significant increment in soma size and dendritic process length versus control and hypothermic treated rats. Post-ischemic damage reurons are therefore involved in NO changes induced by PA that may be prevented by hypothermia treatment. (AU)