Effects of sciatic nerve transection on ultrastructure, NADPH-diaphorase reaction and serotonin-, tyrosine hydroxylase-, c-Fos-, glucose transporter 1- and 3-like immunoreactivities in frog dorsal root ganglion

Frogs have been used as an alternative model to study pain mechanisms. Since we did not find any reports on the effects of sciatic nerve transection (SNT) on the ultrastructure and pattern of metabolic substances in frog dorsal root ganglion (DRG) cells, in the present study, 18 adult male frogs (Rana catesbeiana) were divided into three experimental groups: naive (frogs not subjected to surgical manipulation), sham (frogs in which all surgical procedures to expose the sciatic nerve were used except transection of the nerve), and SNT (frogs in which the sciatic nerve was exposed and transected). After 3 days, the bilateral DRG of the sciatic nerve was collected and used for transmission electron microscopy. Immunohistochemistry was used to detect reactivity for glucose transporter (Glut) types 1 and 3, tyrosine hydroxylase, serotonin and c-Fos, as well as nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-diaphorase). SNT induced more mitochondria with vacuolation in neurons, satellite glial cells (SGCs) with more cytoplasmic extensions emerging from cell bodies, as well as more ribosomes, rough endoplasmic reticulum, intermediate filaments and mitochondria. c-Fos immunoreactivity was found in neuronal nuclei. More neurons and SGCs surrounded by tyrosine hydroxylase-like immunoreactivity were found. No change occurred in serotonin- and Glut1- and Glut3-like immunoreactivity. NADPH-diaphorase occurred in more neurons and SGCs. No sign of SGC proliferation was observed. Since the changes of frog DRG in response to nerve injury are similar to those of mammals, frogs should be a valid experimental model for the study of the effects of SNT, a condition that still has many unanswered questions.

Ultrastructural description of rabies virus infection in cultured sensory neurons

Primary cultures were made from adult mouse spinal ganglia for depicting an ultrastructural description of rabies virus (RABV) infection in adult mouse sensory neuron cultures; they were infected with rabies virus for 24, 36, and 48 h. The monolayers were processed for transmission electron microscopy and immunochemistry studies at the end of each period. As previously reported, sensory neurons showed great susceptibility to infection by RABV; however, in none of the periods evaluated were assembled virions observed in the cytoplasm or seen to be associated with the cytoplasmic membrane. Instead, fibril matrices of aggregated ribonucleoprotein were detected in the cytoplasm. When infected culture lysate were inoculated into normal animals via intra-cerebral route it was observed that these animals developed clinical symptoms characteristic of infection and transmission electron microscopy revealed assembled virions in the cerebral cortex and other areas of the brain. Sensory neurons infected in vitro by RABV produced a large amount of unassembled viral ribonucleoprotein. However, this intracellular material was able to produce infection and virions on being intra-cerebrally inoculated. It can thus be suggested that the lack of intracellular assembly in sensory neurons forms part of an efficient dissemination strategy.

Morphometric relationships between satellite and nerve cells in the sensory lumbar ganglia of the domestic fowl in different pre-and post-hatching stages

Foi feito um estudo combinado a microscopia óptica e eletrônica em embriöes de 10 a 18 dias e em espécimens de 8, 35, 61, e 120 dias após a eclosäo de galo doméstico. O volume nuclear da célula nervosa, praticamente näo varia após o 18ª dia de incubaçäo enquanto que, considerável aumento do mesmo volume para células satélites foi observado. O volume citoplasmático varia intensa e progressivanebte para ambos os tipos de células, sendo menor para célula nervosa. Há relativa proporcionalidade de aumento de volume para ambos os tipos de células, sendo contudo, mais intenso para células satélites. Säo feitas consideraçöes de ordem morfofuncional

Light and dark cells in the lumbar sensory ganglia of pre and post-hatching domestic fowl

Foram identificadas, por microscopia eletrônica, células satélites claras e escuras em gânglios sensitivos lombares do galo doméstico, em 8 fases pré e 4 fases pós-eclosäo. Algumas diferenças citológicas encontradas, referentes ao retículo endoplasmáticos rugoso, ribosomos, aparelho de Golgi e complexos juncionais, sugerem a existência de características funcionais distintas para ambos os tipos de células satélites

A freeze-fracture study on the developing satellite cells of spinal ganglia in the chick embryo

Foi feita análise pelo método da crio-fratura de células satélites em 8 diferentes fases do desenvolvimento do embriäo de galinha, do quinto dia à eclosäo. A disposiçäo laminar característica das células foi observada inicalmente no sétimo dia. Foram encontradas junçöes do tipo <> no 20- dia de incubaçäo. Pequenos grupos ou agregados de partículas foram descritos no sétimo e oitavo dias, mas näo típicas junçöes <>. Vesículas de pinocitose foram apontadas nos diferentes estágios considerados