Differentiation Of Olfactory Cells Research Articles

Rearrangement of Actin Microfilaments in the Development of Olfactory Receptor Cells in Fish

At present, it remains poorly understood how the olfactory neuron migrates through the thick neuroepithelium during its maturation from a stem cell and how it develops a specific sensitivity to environmental odorants after maturation. We investigated the cytochemical features associated with the development of olfactory cells before and after the incorporation of dendrites into the surface of the olfactory epithelium. Using cytochemical staining for the actin cytoskeleton and other cell components, we found that immature neurons acquire a streamlined shape that resembles a «hot-dog» during their migration: a dense layer of actin microfilaments forms beneath the surface membrane of the growing dendrite, and the bulk of the nuclear material moves inside this layer. We have found that when the cell makes contact with its environment, the dendritic terminal develops a wide actin layer, inside which a pore is formed. It is assumed that the functional receptors of odorants generate across this pore the first intracellular signal from environmental water-soluble odorants. These data illustrate the important role of the cytoskeleton in the differentiation of olfactory cells.

Effect of biphasic electrical stimulation on the proliferation and differentiation of olfactory bulb neural precursor cells

Objective To explore the effect of biphasic electrical stimulation (BES) on the proliferation and differentiation of rats olfactory bulb neural precursor cells (OB NPCs). Methods OB NPCs of one day old neonatal rats were isolated, cultured, passaged and identified. They were randomly divided into a control group and an electrical stimulation (ES) group. The OB NPCs in the ES group were exposed to BES with a 50 mV/mm or 100 mV/mm electric field for 24 hours with a pulse width of 8 ms, while the control group was not given electrical stimulation. The immunofluorescent technique and 3(4, 5 dimethythiazol-2-y1)-2, 5-diphenyl tetrazolium bromide (MTT) colorimetric assay were used to assess the cells′ proliferation and differentiation. Results The cell viability and the number of glial fibrillary acidic protein positive cellsin the ES group were significantly higher than in the control group. Conclusions BES may be used as an auxiliary technique for improving cell survival and differentiation in stem cell-based transplantation therapy as it can promote proliferation and differentiation, at least of OB NPCs. Key words: Electrical stimulation; Olfactory bulb; Neural stem cells; Proliferation; Differentiation; Neural repair; Neural regeneration; Nerve injury

Proliferation and differentiation of olfactory cells in primary culture system

A primary culture system of olfactory cells derived from newborn mouse was established by coculturing with a feeder layer of brain astrocytes. In this system, the whole lifespan of olfactory cells could be observed in vitro. Neurogenesis occurred from 5 days after plating and coexistence of immature and mature olfactory cells was observed until day 14. After day 15, immature cells were diminished and most of the culture cells appeared differentiated after day 20. The lifespan of differentiated cells was estimated to be 3 to 6 weeks. Cultured cells expressed growth associated protein 43 (GAP43), neurofilament protein (NFP), protein gene product 9.5 (PGP9.5) and olfactory marker protein (OMP). In addition, other round cells were cytokeratin-positive by immunostaining. RT-PCR of growth factor receptors on the coculture cells revealed the expressions of fibroblast growth factor receptor 2 (FGFR2) and FGFR3, both of which could not be detected in the feeder cell layer of astrocytes. FGFR1 and transforming growth factor beta receptor (TGF beta R) were detected both on the coculture and on feeder cells. FGFR4, insulin-like growth factor 2 receptor (IGF2R) and hepatocyte growth factor receptor (HGFR) could not be detected in both samples. Furthermore, basic FGF, a prototypic FGF, was also found in the coculture system and in feeder cells. The present study indicated FGF might affect regulation of proliferation and differentiation of olfactory cells.