Direct injection into the dorsal root ganglion: technical, behavioral, and histological observations. J Neurosci Methods 2011 Jul 15;199(1):43-55
Date
05/05/2011Pubmed ID
21540055Pubmed Central ID
PMC3742008DOI
10.1016/j.jneumeth.2011.04.021Scopus ID
2-s2.0-79958117790 (requires institutional sign-in at Scopus site) 74 CitationsAbstract
Direct injection of agents into the dorsal root ganglia (DRGs) offers the opportunity to manipulate sensory neuron function at a segmental level to explore pathophysiology of painful conditions. However, there is no described method that has been validated in detail for such injections in adult rats. We have found that 2 μl of dye injected through a pulled glass pipette directly into the distal DRG, exposed by a minimal foraminotomy, produces complete filling of the DRG with limited extension into the spinal roots. Injection into the spinal nerve required 3 μl to achieve comparable DRG filling, produced preferential spread into the ventral root, and was accompanied by substantial leakage of injected solution from the injection site. Injections into the sciatic nerve of volumes up to 10 μl did not reach the DRG. Transient hypersensitivity to mechanical stimulation at threshold (von Frey) and noxious levels (pin) developed after 2 μl saline injection directly into the DRG that was in part attributable to the surgical exposure procedure alone. Only minimal astrocyte activation in the spinal dorsal horn was evident after DRG saline injections. Injection of adeno-associated virus (AAV) vector conveying green fluorescent protein (GFP) transgene resulted in expression as soon as 1 day after injection into the DRG, including fibers in the spinal dorsal horn and columns. AAV injection into the DRG produced additional thermal hypersensitivity and withdrawal from the stroke of a brush and compromised motor performance. These findings demonstrate a method for selective injection of agents into single DRGs for anatomically restricted actions.
Author List
Fischer G, Kostic S, Nakai H, Park F, Sapunar D, Yu H, Hogan QAuthor
Hongwei Yu MD Professor in the Anesthesiology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsAstrocytes
Cells, Cultured
Cold Temperature
Coloring Agents
Dependovirus
Ganglia, Spinal
Genes, Reporter
Genetic Therapy
Genetic Vectors
Green Fluorescent Proteins
Hot Temperature
Hyperalgesia
Indoles
Male
Microinjections
Neuralgia
Psychomotor Performance
Rats
Rats, Sprague-Dawley
Sciatic Nerve
Sensory Receptor Cells
Sodium Chloride
Solutions
Spinal Nerve Roots
Stress, Mechanical
