Análisis morfométrico de las fibras nerviosas del nervio abducente del perro / Morphometric analysis of the nerve fibers of the abducent nerve in dog

Para nuestro estudio hemos analizado la porción intracraneal de los nervios abducentes derechos extraídosde seis perros adultos, de raza pastor alemán. Los nervios fueron analizados con microscopia óptica y microscopiaelectrónica. En todos los nervios hemos calculado su área y analizado las fi bras mielínicas y amielínicas.En ambos tipos de fibras hemos determinado su número, diámetro y área, así como el área y el diámetro delaxón correspondiente y el grosor de la vaina de mielina en las fibras mielínicas. El número medio de fibras esde 2473,00 ± 211,41 mielínicas y 231,25 ± 92,67 amielínicas. El diámetro medio fibrilar fue de 10,45 ± 1,27 mm para las fibras mielínicas y 0,47 ± 0,09 mm para las amielínicas. Nuestro estudio sobre el nervio abducentemuestra que este nervio, en el perro, presenta características estructurales y ultraestructurales semejantes a la de otros nervios y otras especies

The intracranial portion of the abducent nerve was studied in dogs. The nerves were dissected from sixadult German shepherd dogs. The nerves were analysed by both light and electron microscopy. In all nerveswe calculated their area and analysed both myelinated and unmyelinated fibers. In both we determined theirnumber, diameter and area; also the area and diameter of the correspondent axon, and the thickness of the myelinsheath. The mean number of fibers was 2473.00±211.41 for myelinated and 231.25±92.67 for unmyelinatedones. The average fiber diameter was 10.45±1.27 mm for myelinated and 0.47±0.09 mm for unmyelinated. Thisstudy on the abducent nerve demonstrated that dogs shows structural and ultrastructural characteristics similartothose of another nerves and other species

Influence of age on fibre type characteristics in the middle gluteal muscle of Andalusian foals.

34 Andalusian foals of both sexes were divided into three age-groups (A = mean age 1 month, B = 7 months, C = 14 months). Samples of the right m. gluteus medius were stained for m-ATPase and NADH-TR in order to determine fibre type composition and size as well as the relative area occupied by each type. Results revealed no statistically significant variation in the proportion of type I fibre among the three age-groups. Significant differences were recorded, however, for type II fibres; an increase in the proportion of IIA fibres was accompanied by a decrease in IIB ones, the difference being most marked between groups A and B. IIB high-oxidative fibres also decreased, while IIB low-oxidative ones showed no significant variation. All fibre types increased significantly in size; types I and IIA recorded a threefold increase, whereas type IIB showed least growth. The relative area occupied by each type increased significantly between groups A and B, but only IIA fibres recorded a significant increase in relative area between groups B and C.