Localisation of cannabinoid receptor 1 in rat dorsal root ganglion using in situ hybridisation and immunohistochemistry

• Published in: Neuroscience 2003-01, Vol.119 (3), p.803-812
• Main Authors: Bridges, D, Rice, A.S.C, Egertová, M, Elphick, M.R, Winter, J, Michael, G.J
• Format: Article
• Language: English
• Subjects: A-fibre; Animals; Biological and medical sciences; C-fibre; Calcitonin Gene-Related Peptide - metabolism; Cell Size - physiology; Fluorescent Antibody Technique; Ganglia, Spinal - cytology; Ganglia, Spinal - metabolism; Glycoproteins; Lectins - metabolism; Male; Mechanoreceptors - cytology; Mechanoreceptors - metabolism; Medical sciences; Mice; Mice, Knockout; Nerve Fibers, Myelinated - metabolism; Nerve Fibers, Myelinated - ultrastructure; Nerve Fibers, Unmyelinated - metabolism; Nerve Fibers, Unmyelinated - ultrastructure; Neurofilament Proteins - metabolism; Neurons, Afferent - cytology; Neurons, Afferent - metabolism; Neuropharmacology; nociceptor; Nociceptors - cytology; Nociceptors - metabolism; pain; Pain - genetics; Pain - metabolism; Pharmacology. Drug treatments; Psychodysleptics: hallucinogen; Psychology. Psychoanalysis. Psychiatry; Psychopharmacology; Rats; Rats, Wistar; Receptors, Cannabinoid; Receptors, Drug - genetics; Receptors, Drug - metabolism; RNA, Messenger - metabolism
• ISSN: 0306-4522; 1873-7544
• DOI: 10.1016/S0306-4522(03)00200-8

In this study we used in situ hybridisation and double-labelling immunohistochemistry to characterise cannabinoid receptor 1 (CB 1) expression in rat lumbar dorsal root ganglion (DRG) neurons. Approximately 25% of DRG neurons expressed CB 1 mRNA and displayed immunoreactivity for CB 1. Sixty-nine percent to 82% of CB 1-expressing cells were also immunoreactive for neurofilament 200, indicative of myelinated A-fibre neurons, which tend to be large- and medium-sized DRG neurons (>600 μm 2). Approximately 10% of CB1-expressing cells also expressed transient receptor potential vanilloid family ion channel 2 (TRPV2), the noxious heat-transducing channel found in medium to large lightly myelinated Aδ-fibre DRG neurons. Seventeen percent to 26% of CB 1-expressing cells co-stained using Isolectin B4, 9–10% for calcitonin gene-related peptide and 11–20% for transient receptor potential vanilloid family ion channel 1 (TRPV1), predominantly markers of small non-myelinated C-fibre DRG neurons (