Ganglion neurons

Hirschsprung s disease have ETB receptor mutations). The lack of ET-3/ETB receptor results in the absence of parasympathic ganglionic neurons in the myenteric plexus (Auerbach). Mice with an ET-3/ETB receptor disruption die within 2 weeks after birth. In transgenic mice, in which the expression of the ETB receptor is driven by the dopamine (3-hydroxylase promoter, normal myenteric plexus are present and no enteric disorder develops. These mice, however, show a salt-sensitive hypertension, which can be efficiently treated with amiloride, indicating that ETB receptors are involved in the regulation of natriuresis via the amilorid-sensitive sodium channel ENaC. 

TK NKxr displays a broad distribution in both peripheral tissues and in the central nervous system (CNS). In both CNS and enteric neurons, NKxr stimulation increase their excitability, whereas in trigeminal ganglion neurons SP has no intrinsic electrophysio-logical effects but is capable to enhance the amplitude of the inward current induced by the stimulation of serotonin 5-HT3 recqrtors. This enhancement dqjends on the activation of PKC via the stimulation of NKX recqrtors. This is an interesting case of receptor cross talk. Other functions of NKxr have been also highlighted. 

Hydrogen ions accumulate in tissue damaged by inflammation and ischaemia and so pH is lowered. These protons may activate nociceptors directly via their own family of ion channels as well as sensitising them to mechanical stimulation. Acid-sensing ion channels (ASICS) are a family of sodium channels that are activated by protons — of special interest is one type found only in small dorsal root ganglion neurons that possibly are responsible for activation of nociceptors. Although the transduction of mechanical stimuli is poorly understood, ASICs are closely related to channels that respond to stretch. 

Dolphin, A. C., Forda, S. R. and Scott, R. H. Calcium-dependent currents in cultured rat dorsal root ganglion neurons are inhibited by an adenosine analogue. /. Physiol. (Lond.) 373 47-61,1986. 

Neuropeptides are crucial to pain perception. Substance P is released in the spinal cord by a subset of dorsal root ganglion neurons Substance P is crucial to the sensation of noxious stimuli. Substance P binds to the neurokinin-1... 

Megadosage vitamin B6 (pyridoxine) and cisplatin cause sensory neuronopathy. Pyridoxine toxicity, usually the result of inappropriate self-overmedication, kills dorsal root ganglion neurons. Affected individuals become severely ataxic because of loss of proprioceptive afferent input to the cerebellum. A similar syndrome is elicited by cisplatin chemotherapy. Neurotrophin-3 treatment is effective in protecting dorsal root ganglion neurons in experimental animals against these toxins [48,49]. 

Sahara, Y., Noro, N., Iida, Y., Soma, K., and Nakamura, Y. (1997) Glutamate receptor subunits GluR5 and KA-2 are coexpressed in rat trigeminal ganglion neurons. J. Neurosci. 17, 6611-6620. 

Ginsburg KS, Narahashi T (1993) Differential sensitivity of tetrodotoxin-sensitive and tetrodotoxin-resistant sodium channels to the insecticide allethrin in rat dorsal root ganglion neurons. Brain Res 627 239-248... 

Badio B, Padgett WL, Daly JW. (1997). Ibogaine a potent noncompetitive blocker of ganglionic/neuronal nicotinic receptors. Mol Pharmacol. 51(1) 1-5. 

Fig. 1. Hydra oligactis whole mount labeled with monoclonal antibody JDl. (A) Isolated ganglionic neuron in the body column, scale bar = 50 om (B) hypostomal nerve net with sensory neurons of the mouth at the left and ganglionic neurons of the perihypostomal ring to the right, scale bar = 50 pm (C) cell bodies of hypostomal sensory neurons extending from the mesoglea (processes) to the surface of the ectoderm, scale bar = 25 pm.

Oda A et al Characteristics of ropivacaine block of Na+ channels in rat dorsal root ganglion neurons. Anesth Analg 2000 91 1213. [PMID 11049911]... 

Bielik, N., Kocsis, P., Farkas, S. Whole-cell patch-clamp analysis of the effect of RGH-5002, a novel centrally acting muscle relaxant drug on voltage-gated sodium channels of dorsal root ganglion neurons, Naunyn Schmiedeberg s Arch. 1997, 356, Suppl 1, R25. 

Tanaka, M. Cummins, T. R., Ishikawa, K., Dib-Hajj, S. D., Black, J. A., Waxman, S. G. SNS Na+ channel expression increases in dorsal root ganglion neurons in the carrageenan inflammatory pain model, Neuroreport 1998, 9, 967-972. 

Abdulla, F. A. and Smith, P. A. Axotomy- and autotomy-induced changes in Ca2+ and C channel currents of rat dorsal root ganglion neurons, Journal of Neurophysiology 2001, 85, 644-658. 

Everill, B. and Kocsis, J. D. Nerve growth factor maintains potassium conductance after nerve injury in adult cutaneous afferent dorsal root ganglion neurons, Neuroscience 2000, 100, 417-422. 

Ueno, S., Tsuda, M., Iwanga, T., Inoue, K. Cell-type specific ATP-activated responses in the rat dorsal root ganglion neurons, Br. J. Pharmacol. 1999, 126, 429-436. 

Szallasi, A,. Blumberg, P.M., Annicelli, L.L., Krause, J.E., Cortright, D.N. The cloned rat vanilloid receptor VR1 mediates both R-type binding and C-type calcium response in dorsal root ganglion neurons, Mol. Pharmacol. 1999, 56, 581-587. 

Mouse dorsal root ganglionic neurons Inhibition Wu et al., 2005... 

Wu YL, Ohsaga A, Oshiro T, Iinuma K, Kondo Y, Ebihara S, Sasaki H, Maruyama Y. 2005. Suppressive effects of red wine polyphenols on voltage-gated ion channels in dorsal root ganglionic neuronal cells. Tohoku J Exp Med 206 141-150. 

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