Expression of PTPRO in the Interneurons of Adult Mouse Olfactory Bulb

PTPRO is a receptor-type protein tyrosine phosphatase (PTP) with a single catalytic domain in its cytoplasmic region and multiple fibronectin type III-like domains in its extracellular region. In the chick, PTPRO mRNA has been shown to be particularly abundant in embryonic brain, and PTPRO is implicated in axon growth and guidance during embryonic development. However, the temporal and spatial expression of PTPRO protein in the mammalian CNS, particularly in the juvenile and adult mammalian brain, has not been evaluated in any detail. By immunohistofluorescence analysis with a monoclonal antibody to PTPRO, we show that PTPRO is widely expressed throughout the mouse brain from embryonic day 16 to postnatal day 1, while expression is largely confined to the olfactory bulb (OB) and olfactory tubercle in the adult brain. In the OB, PTPRO protein is expressed predominantly in the external plexiform layer, the granule cell layer, and the glomerular layer (GL). In these regions, expression of PTPRO is predominant in interneurons such as γ-aminobutyric acid (GABA)-ergic or calretinin (CR)-positive granule cells. In addition, PTPRO is expressed in GABAergic, CR-positive, tyrosine hydroxylase-positive, or neurocalcin-positive periglomerular cells in the GL. Costaining of PTPRO with other neuronal markers suggests that PTPRO is likely to be localized to the dendrites or dendritic spines of these olfactory interneurons. Thus, PTPRO might participate in regulation of dendritic morphology or synapse formation of interneurons in the adult mouse OB

A Simple Electrostatic Device for Eliminating Tobacco Sidestream Smoke to Prevent Passive Smoking

An electrostatic apparatus was constructed to capture tobacco sidestream smoke. This apparatus consisted of a perforated polypropylene plate with metal spikes and a grounded metal net arrayed in parallel at a defined interval. Spikes were negatively charged to positively polarize the net and an electric field was formed between the opposite charges of the spike tips and the grounded net. Discharge from the spike tips occurred, which depended on the pole distance and the voltage applied to the spikes. At lower voltages (<12.1 kV) that do not cause arc discharge from the tips, a corona discharge occurred with the generation of an ionic wind from the spiked plate to the net. This discharge increased in direct proportion to the applied voltage and relative humidity, while a larger corona discharge generated a stronger ionic wind. The ionic wind involved negative ions and the number of negative ions in the wind increased with increasing applied voltage. The optimal voltage (10 kV) generated sufficient negative ions to ionize smoke particles in the electric field, before the ionized smoke particles were successfully captured by the oppositely charged metal net. Thus, this study provides an experimental basis for the practical application of an electrostatic-based method to prevent the production of tobacco sidestream smoke that leads to passive smoking by non-smokers