Description of the cave organ in three species of the genus Belminus (Hemiptera: Reduviidae: Triatominae) by optical and scanning electron microscopy

The cave organ is a sensory receptor in the antenna pedicel of some Reduviidae. This paper describes this organ for the first time in three species of the genus Belminus, Belminus corredori, Belminus ferroae and Belminus herreri, by optical and scanning electron microscopy. The structures presented a general pattern similar to one reported for other species of Triatominae.

Ultrastructural Changes of Myotendinous Nerve Endings following Recession or Resection Procedures of Extraocular Muscle Surgeries in Cats

To verify the postoperative ultrastructural changes of the myotendinous nerve endings of feline extraocular muscles, which are known as proprioceptors. Sixteen recti of four cats were used and divided into three groups. In group A, eight lateral recti were recessed. In group B, four medial recti were resected by 10 mm from insertion to include the myotendinous junction. In group C, four medial recti were resected by 4 mm of muscle bellies only, without disturbing the myotendinous junction. Four weeks after surgery, specimens were examined with electron microscopy. In group A, overall neural structures were well maintained with slight axonal degeneration. In group B, only muscle fibers were observed without any regeneration of neural sprouts. In group C, axonal disintegration and shrinkage were evident. These results indicate that myotendinous nerve endings can be damaged in strabismus surgery, and that resection was more invasive than recession in disrupting myotendinous nerve endings.

Olfaction in the Colorado potato beetle: ultrastructure of antennal sensilla in Leptinotarsa sp.

Sensillae on the antennae of the Colorado potato beetle, Leptinotarsa decemlineata are described using scanning (SEM) and transmission (TEM) electron microscopy and compared with SEM observations of antennal sensilla in L. haldemani and L. texana. In all the three species, 13 distinct sensillar types were identified with a higher density of sensilla in the more polyphagous species, L. decemlineata than in the moderately host specific L. haldemani and the highly host specific L. texana. Cuticular specializations and the predominance of olfactory sensilla are discussed in relation to host specificity in the three species.

Ultrastructure and chaetotaxy of sensory receptors in the cercaria of a species of Allopodocotyle Pritchard, 1966 (Digenea: Opecoelidae)

Previous investigations of sensory systems in opecoelid cercariae have focused on chaetotaxy and ultrastructure of sensory receptors. They revealed chaetotaxic patterns within family, genus, and species as well as different receptors. Chaetotaxic and ultrastructural observations have rarely been combined. We investigated the ultrastructure of cercarial sensory receptors in conjunction with chaetotaxy and neuromorphology in a species of Allopodocotyle. Cercariae were treated with acetylthiocholine iodide and silver nitrate, and some were processed for light, scanning (SEM), and transmission (TEM) electron microscopy. Five nerve regions were distinguished. Chaetotaxy was consistent with that of other opecoelids. Five types of receptors were distinguished with SEM. Types differed in number of cilium-like structures (one or more), length of cilium-like structure (short, moderately long, or long), presence or absence of a tegumentary collar, and length of tegumentary collar (low, moderately low, or very high). Internal ultrastructure of some types revealed unsheathed cilium-like structures, basal body, and thickened nerve collars. Possible subtegumentary and sheathed receptors are introduced. Some receptor types were site-specific. For example, receptors with multiple cilium-like structures were concentrated on cephalic region whereas receptors with short cilium-like structure were widespread throughout most regions. Ultrastructure and site-specificity observations suggest that most receptors are mechanoreceptors

Fine structure of sensore nerve endings and SEM study of the palatine mucosa of rats

Se estudió la estructura fina de las terminaciones sensoriales nerviosas, a través de microscopÍa electrónica de barrido de la superficie celular y del tejido conectivo epitelial. La superficie epitelial de la mucosa palatina de la rata mostró una superficie de células planas y algunas elevaciones de la mucosa. La superficie de la célula está caracterizada por la presencia de numerosos micropliegues. Especímenes tratados con HCL-colagenasa revelaron que la interfase del tejido conectivo-epitelial presentaba varios surcos, circulares y alargados. Las pequeñas proyecciones citoplasmáticas son claramente visibles. Las terminaciones nerviosas libres bajo el epitelio se encuentran en el pequeño tejido conectivo papilar y están circundados por una delgada lámina de células de Schwann. El axoplasma mostró numerosas mitocondrias, neurofilamentos cuerpos multicorpustulares y pequeñas protusiones citoplasmáticas

Morfologia das terminacoes nervosas sensitivas da porcâo anterior da mucosa lingual de macaco cebus apella / Sensitive nervous terminations morphology of the anterior lingual mucosa of the macaco cebus apella

Terminaçöes nervosas sensitivas da porçäo anterior de mucosa lingual de 6 macacos Cebus apella foram estudas, através de técnica de impregnación pela prata (WINKELMANN & SCHMIT 1957). Os resultados revelam que as fibras nervosas subepiteliais säo provenientes de camada profunda da língua e formam terminaçöes nervosas sensitivas simples e ramificadas. As papilas fingiformes contém numerosas fibras nervosas que constituem um verdadeiro plexo e as filiformes possuem as terminaçöes nervosas livres