6. Dorsal root ganglion neurons: electrical properties and cell type

It has been shown that there are two main morphological neuronal types in rat and mouse dorsal root ganglia (d.r.g.s), the large light (LL) and small dark (s.d.) neurons. Each population has a normally distributed range of cell sizes with different means, and the size ranges of the two populations overlap (Lawson 1979; Lawson & Harper, in press).

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P4.18 Electrical properties of subpopulations of thoracic dorsal root ganglion neurons and their implications for the sensory innervation of the jejunum in the adult mouse

Autonomic Neuroscience ◽

10.1016/j.autneu.2009.05.185 ◽

2009 ◽

Vol 149 (1-2) ◽

pp. 99-100

Author(s):

L.L. Tan ◽

C.R. Anderson ◽

J.C. Bornstein ◽

E.A. Jennings

Keyword(s):

Electrical Properties ◽

Dorsal Root Ganglion ◽

Dorsal Root ◽

Adult Mouse ◽

Dorsal Root Ganglion Neurons ◽

Sensory Innervation ◽

Ganglion Neurons

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Cell type-specific ATP-activated responses in rat dorsal root ganglion neurons

British Journal of Pharmacology ◽

10.1038/sj.bjp.0702319 ◽

1999 ◽

Vol 126 (2) ◽

pp. 429-436 ◽

Cited By ~ 138

Author(s):

Shinya Ueno ◽

Makoto Tsuda ◽

Toshihiko Iwanaga ◽

Kazuhide Inoue

Keyword(s):

Dorsal Root Ganglion ◽

Dorsal Root ◽

Dorsal Root Ganglion Neurons ◽

Cell Type ◽

Cell Type Specific ◽

Ganglion Neurons

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Dorsal Root Ganglion Neurons Innervating Skeletal Muscle Respond to Physiological Combinations of Protons, ATP, and Lactate Mediated by ASIC, P2X, and TRPV1

Journal of Neurophysiology ◽

10.1152/jn.01344.2007 ◽

2008 ◽

Vol 100 (3) ◽

pp. 1184-1201 ◽

Cited By ~ 185

Author(s):

Alan R. Light ◽

Ronald W. Hughen ◽

Jie Zhang ◽

Jon Rainier ◽

Zhuqing Liu ◽

...

Keyword(s):

Skeletal Muscle ◽

Dorsal Root Ganglion ◽

Calcium Imaging ◽

Dorsal Root ◽

Dorsal Root Ganglion Neurons ◽

Drg Neurons ◽

Molecular Receptors ◽

Trpv1 Receptors ◽

Ganglion Neurons ◽

Two Populations

The adequate stimuli and molecular receptors for muscle metaboreceptors and nociceptors are still under investigation. We used calcium imaging of cultured primary sensory dorsal root ganglion (DRG) neurons from C57Bl/6 mice to determine candidates for metabolites that could be the adequate stimuli and receptors that could detect these stimuli. Retrograde DiI labeling determined that some of these neurons innervated skeletal muscle. We found that combinations of protons, ATP, and lactate were much more effective than individually applied compounds for activating rapid calcium increases in muscle-innervating dorsal root ganglion neurons. Antagonists for P2X, ASIC, and TRPV1 receptors suggested that these three receptors act together to detect protons, ATP, and lactate when presented together in physiologically relevant concentrations. Two populations of muscle-innervating DRG neurons were found. One responded to low metabolite levels (likely nonnoxious) and used ASIC3, P2X5, and TRPV1 as molecular receptors to detect these metabolites. The other responded to high levels of metabolites (likely noxious) and used ASIC3, P2X4, and TRPV1 as their molecular receptors. We conclude that a combination of ASIC, P2X5 and/or P2X4, and TRPV1 are the molecular receptors used to detect metabolites by muscle-innervating sensory neurons. We further conclude that the adequate stimuli for muscle metaboreceptors and nociceptors are combinations of protons, ATP, and lactate.

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GABAA-receptor-activated current in dorsal root ganglion neurons freshly isolated from adult rats

Journal of Neurophysiology ◽

10.1152/jn.1990.64.1.57 ◽

1990 ◽

Vol 64 (1) ◽

pp. 57-63 ◽

Cited By ~ 24

Author(s):

G. White

Keyword(s):

Dorsal Root Ganglion ◽

Action Potential ◽

Gabaa Receptor ◽

Dorsal Root ◽

Dorsal Root Ganglion Neurons ◽

Action Potential Generation ◽

Potential Generation ◽

Drg Neurons ◽

Ganglion Neurons ◽

Two Populations

1. gamma-Aminobutyric acid (GABA) is the major inhibitory neurotransmitter affecting dorsal root ganglion (DRG) neurons. This study compares properties of current activated by the GABAA receptor in two populations of DRG neurons. DRG neurons were isolated from adult rat with the use of enzymatic and mechanical means. Within hours of being isolated, neurons were recorded from with the use of the whole-cell variant of the patch-clamp technique. 2. One population of neurons exhibited an afterdepolarizing potential (ADP), a low threshold for action-potential generation (-45 to -50 mV), a short-duration action potential (less than 2 ms) that was abolished in the presence of 1-2 microM tetrodotoxin (TTX), and an insensitivity to 50 nM capsaicin. The second population of neurons exhibited a high threshold for action-potential generation (less than -40 mV), a shoulder on the falling phase of the action potential, insensitivity of action-potential generation to TTX (1-2 microM), and a depolarizing response to application of 50 nM capsaicin. 3. Sensitivity to GABA (over the range of 1–1,000 microM) was comparable for the two populations of neurons. 4. GABA-activated current was greater in ADP neurons than in non-ADP-type neurons of a comparable diameter (30-50 microns). The mean +/- SE amplitude of current activated by 10 microM GABA in ADP neurons was 0.310 +/- 0.050 nA (range = 0.110-0.460 nA, n = 8), and 0.037 +/- 0.016 nA (range = 0.010-0.130 pA, n = 7) in non-ADP neurons. Ten microM GABA elicited cell firing in ADP neurons but not in non-ADP neurons.(ABSTRACT TRUNCATED AT 250 WORDS)

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