The three-dimensional reconstruction of the innervation pattern in the lymphoid compartment of the ovine pharyngeal tonsil highlighted a possible way of neuro-invasion by the scrapie agent.

Conference (2012, October 19)

Neuroimmune connections in ovine pharyngeal tonsil: potential site for prion neuroinvasion

in Cell & Tissue Research (2012)

Recent studies have proved the possible implication of nasal associated lymphoid tissues, mainly the pharyngeal tonsil, in prion pathogenesis. However, the mechanisms of this neuroinvasion are still being ... [more ▼]

Recent studies have proved the possible implication of nasal associated lymphoid tissues, mainly the pharyngeal tonsil, in prion pathogenesis. However, the mechanisms of this neuroinvasion are still being debated. To determine the potential sites for prion neuroinvasion inside the ovine pharyngeal tonsil, the topography of neurofilaments heavy (200 kDa) (NFH), neurofilaments light (70 kDa) (NFL) and glial fibrillar acidic protein (GFAP) was semi-quantitatively analysed inside the different compartments of the tonsil. The results showed that the most innervated areas were the interfollicular area and the connective tissue located beneath the respiratory epithelium. Even if the germinal centre of the lymphoid follicles was poorly innervated, the existence of rare follicular dendritic cell-nerve synapses inside the germinal centre indicates that this mechanism of neuroinvasion is possible but unlikely to be unique. The host PRNP genotype did not influence the pattern of innervation in these different tonsil compartments, unlike age: an increase of nerve endings in a zone of high trafficking cells beneath the respiratory epithelium occurred with ageing. A minimal age-related increase of innervation inside the lymphoid follicles was also observed. An increase in nerve fibre density around the lymphoid follicles, in an area rich in mobile cells able to transport PrPd, could ensure a more efficient infectivity, not in the early phase but in the advanced phase of lymphoinvasion after amplification of PrPd, or could act as direct site of entry during neuroinvasion. [less ▲]

Distribution and frequency of nerves fibres in palatine and pharyngeal tonsils

Poster (2009, October)

Neuroimmune contact between peripheral nervous system and follicular dendritic cells in ovine lymph organs

Poster (2008, October)

Are CNA42 and FDC-B1 directed against ovine follicular dendritic cells?

Poster (2006, October)

Histological study of equine interphalangeal joints

Poster (2005, July)

CD-rom de Quizz d'histologie spéciale des animaux domestiques, Faculté de Médecine Vétérinaire

Learning material (2004)

Morphology, growth and modelling of bone tissue

in Annales de Médecine Vétérinaire (2004), 148(1), 1-13

Bone is an essential part of the squeletton. Besides its mechanic properties, bone has an important role in metabolism regulation because it acts as a reservoir for the storage of minerals essential to ... [more ▼]

Bone is an essential part of the squeletton. Besides its mechanic properties, bone has an important role in metabolism regulation because it acts as a reservoir for the storage of minerals essential to provide homeostasy. This article describes bone morphology and different ways of classification of this tissue. It gives the composition of organic and mineral extracellular bone matrix, underlines the dynamic character of bone tissue, details the cellular morphology and the metabolism of the elements acting on the synthesis/resorption mechanisms : osteoprogenitor cells, osteoblasts, osteocyts and osteoclasts. It relates the histogenesis of bone tissue and develops the different types of ossification: intramembranous, periostic, endochondral and osteonal remodeling. The last part of this article describe some dietetary and hormonal influences on bone tissue. [less ▲]