Article

Expression of the TRPM8-immunoreactivity in dorsal root ganglion neurons innervating the rat urinary bladder.

Department of Urology, Kurume University School of Medicine, Asahimachi 67, Kurume 830-0011, Fukuoka, Japan.
Neuroscience Research (impact factor: 2.25). 07/2009; 65(3):245-51. DOI:10.1016/j.neures.2009.07.005 pp.245-51
Source: PubMed

ABSTRACT The neurochemical phenotypes of the transient receptor potential melastatin-8 (TRPM8)-immunoreactive afferent neurons innervating the rat urinary bladder were examined by using a highly sensitive tyramide signal amplification method, combined with wheat-germ agglutinin-horseradish peroxidase (WGA-HRP) retrograde tracing. TRPM8-immunoreactivity was detected in a small proportion of the WGA-HRP-labeled bladder afferent neurons in the dorsal root ganglia of the Th13-L1 (1.14%) and the L6-S1 (1.27%), and these neurons were small in size (<600 microm(2)). The 82.6+/-3.8% of the TRPM8-immunoreactive bladder afferent neurons and 80.9+/-1.5% of the total population of the TRPM8-immunoreactive afferent neurons in the observed dorsal root ganglia expressed NF200. On the other hand, the proportions of the co-expression of TRPM8 and nociceptive markers such as calcitonin gene-related peptide (CGRP), transient receptor potential vanilloid-1 (TRPV1), and isolectin B4 (IB4) in the bladder afferent neurons (81.5+/-5.2% for CGRP, 36.1+/-4.0% for TRPV1, and 15.8+/-5.5% for IB4) were higher in comparison to those in the total population of the TRPM8-immunoreactive afferent neurons (21.9+/-2.4% for CGRP, 16.6+/-1.7% for TRPV1, and 5.4+/-0.5% for IB4), although no significant difference existed for IB4. Our results suggest that the TRPM8-expressing bladder afferents should be classified as Adelta-fibers and C-fibers, while some of these afferents may be involved in nociceptive sensations.

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Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.

Keywords

afferents
 
bladder afferent neurons
 
calcitonin gene-related peptide
 
isolectin B4
 
neurochemical phenotypes
 
nociceptive markers
 
observed dorsal
 
rat urinary bladder
 
sensitive tyramide signal amplification method
 
small proportion
 
total population
 
transient receptor potential melastatin-8
 
transient receptor potential vanilloid-1
 
TRPM8
 
TRPM8-expressing bladder afferents
 
TRPM8-immunoreactive afferent neurons
 
TRPM8-immunoreactive bladder afferent neurons
 
TRPM8-immunoreactivity
 
WGA-HRP-labeled bladder afferent neurons
 
wheat-germ agglutinin-horseradish peroxidase