ABSTRACT
We developed a method that allows us to label nociceptive neurons innervating tooth-pulp in rat trigeminal ganglion neurons using a retrograde fluorescence-tracing method, to record ATP-activated current in freshly isolated fluorescence-labeled neurons and to conduct single cell immunohistochemical staining for P2X1 and P2X3 subunits in the same neuron. Three types of ATP-activated current in these neurons (F, I and S) were recorded. The cells exhibiting the type F current mainly showed positive staining for P2X3, but negative staining for P2X1. The results provide direct and convincing evidence at the level of single native nociceptive neurons for correlation of the characteristics of ATP-activated currents with their composition of P2X1 and P2X3 subunits and cell size. The results also suggest that the P2X3, but not P2X1, is the main subunit that mediates the fast ATP-activated current in nociceptive neurons.
ABSTRACT
We developed a method that allows us to label nociceptive neurons innervating tooth-pulp in rat trigeminal ganglion neurons using a retrograde fluorescence-tracing method, to record ATP-activated current in freshly isolated fluorescence-labeled neurons and to conduct single cell immunohistochemical staining for P2X1 and P2X3 subunits in the same neuron. Three types of ATP-activated current in these neurons (F, I and S) were recorded. The cells exhibiting the type F current mainly showed positive staining for P2X3, but negative staining for P2X1. The results provide direct and convincing evidence at the level of single native nociceptive neurons for correlation of the characteristics of ATP-activated currents with their composition of P2X1 and P2X3 subunits and cell size. The results also suggest that the P2X3, but not P2X1, is the main subunit that mediates the fast ATP-activated current in nociceptive neurons.
Subject(s)
Animals , Rats , Action Potentials , Physiology , Adenosine Triphosphate , Metabolism , Dental Pulp , Physiology , Nociceptors , Cell Biology , Physiology , Rats, Sprague-Dawley , Receptors, Purinergic P2X1 , Metabolism , Receptors, Purinergic P2X3 , Metabolism , Tissue Distribution , Trigeminal Nerve , Cell Biology , MetabolismABSTRACT
<p><b>BACKGROUND</b>Differential diagnosis of intracranial hemorrhage and calcification is a common problem encountered in clinical imaging diagnosis. The purpose of this study was to investigate the feasibility of T2 measurement on gradient echo (GRE) T2-weighted imaging (T2WI) in differential diagnosis of intracranial hemorrhage and calcification.</p><p><b>METHODS</b>Thirty-eight hemorrhagic foci in 18 patients and 11 calcification foci in seven patients were included in this study. The diagnosis of hemorrhage and calcification was confirmed in all cases with enhanced T2 weighted angiography (ESWAN) magnetic resonance imaging (MRI) and CT respectively. The significance for the difference of T2 value between the central and peripheral areas of hemorrhage and calcification lesions was tested with univariate analysis of variance.</p><p><b>RESULTS</b>The detection rate of GRE T2 WI on intracranial hemorrhage was 1.9-fold higher than that of CT, especially for the hemorrhage in the brainstem and cerebellum. However, GRE T2WI was far less sensitive to calcification than CT. There was a significant difference in the T2 value between the central area of hemorrhage and calcification (P < 0.001), though no difference in the T2 value was obtained between the peripheral area of hemorrhage and calcification (P > 0.05).</p><p><b>CONCLUSIONS</b>Quantitative measurement of T2 value on GRE T2 WI with a single MRI examination provides a fast, convenient, and effective means in differential diagnosis between intracranial hemorrhage and calcification, which may thus reduce the medical cost and save precious time for clinical management.</p>