Mitsuru Fujiwara

Distribution of calcium binding proteins in sensory organs of the ear, nose and throat

Distributions of spot-35 protein (S-35), calbindin (CaB), and parvalbumin (PaV), three types of calcium-binding protein, were examined immunohistochemically in sensory organs of the ear, nose and throat in guinea pigs and rats. Immunoreactivity of S-35 and CaB was found in the outer hair cells and in vestibular sensory cells situated at the top of the ampulla, and in some cells in the macula. Microvillar cells in the olfactory epithelium, periglomerular cells, and small numbers of cells in the mitral cell layer in the olfactory bulb reacted to anti-S-35 and anti-CaB antisera. In taste buds, most gustatory receptor cells reacted to anti-CaB, although a few reacted to anti-S-35 antiserum. Neuron-like cells in the upper respiratory tract reacted similarly to these antisera. No PaV-immunoreactivity was found in any region. These results indicate that S-35 and CaB play important roles in the special kinds of mechanoreceptor and chemoreceptor cells found in the otolaryngeal area.

Age-related changes in dividing cells of the olfactory epithelium of the maturing guinea pig.

Abstract Changes in dividing cells of the olfactory epithelium from guinea pigs of different ages were examined by immunohistochemical staining using anti-proliferating cell nuclear antigen antibody. Numerous dividing cells were scattered diffusely in the basal layer of the olfactory epithelium at 1 and 2 months following birth and then gradually decreased with maturation until 4 months. Findings then remained constant between 4 and 24 months. Subsequently, cell numbers were found to decrease as animals became older. The number of olfactory receptor cells did not vary significantly between 1 and 30 months. Although no correlation could be found between the numbers of dividing cells and olfactory receptor cells, it is still possible that the longevity of the olfactory receptor cells changes to maintain the overall size of the neuronal population.

Expressions of a calcium-binding protein (spot35/calbindin-D28k) in mouse olfactory cells: possible relationship to neuronal differentiation

We used immunohistochemistry to investigate the expression of spot35/calbindin-D28k (calbindin) in mouse olfactory epithelium during development. Cell stages of immunopositive olfactory cells were determined by comparing the levels of proliferating cell nuclear antigen (PCNA). Calbindin-positive cells were abundant in the middle layer of the epithelium of animals before 2 weeks of age and gradually diminished during development. Only low levels were detectable near the basement membrane in the adult. Changes of calbindin-positive cells in terms of number and distribution were apparently compatible with localization changes of premature olfactory cells. PCNA overlapped calbindin in the nasal mucosa at lower magnifications on stained serial sections and immunohistochemical double staining revealed that calbindin-mmunoreactive cells were located mainly just above PCNA-immunoreactive cells in the basal layer of the epithelium. This indicated that calbindin is expressed postmitotically in immatureolfactory cells and is lost by mature cells. These findings suggest that calbindin might support the maturation of the olfactory cells, such as the projection of the neuronal processes, by stabilizing intracellular calcium ions in immature cells.

Examination of the Olfactory Cleft in Congenital Anosmia.

Nine patients with congenital anosmia were evaluated clinically and pathologically, and olfactory mucosal biopsy was performed in seven of them. Biopsied mucosa of the olfactory cleft was examined with H . E. and immunohistochemical staining.All patients were anosmic when tested with T&T olfactometry and intravenous Alinamine, but most of the patients were responsive to chemical irritants. Three of them had a family history of anosmia.Histopathologically, all specimens showed only respiratory mucosa. Immunohistochemical examination showed an absence of olfactory receptor cells which react with anti-neuron-specific enolase antiserum in all the mucosal specimens.These results indicate that olfactory mucosa is not present and the olfactory cleft is covered with respiratory mucosa in patients with congenital anosmia.