Biomaterial Database

Effects of substance P on excitability and ionic currents of normal and axotomized rat dorsal root ganglion neurons. 2001

F A Abdulla, and M J Stebbing, and P A Smith

Department of Physical Therapy, School of Allied Health Professions, Tennessee State University, Nashville, Tennessee 37209, USA.

Substance P (SP) may act within dorsal root ganglia (DRG) to modulate the transmission of nociceptive information. Because peripheral nerve injury (axotomy) alters the peptide content of sensory neurons, we used whole-cell recording to examine the effects of sciatic nerve section on the sensitivity of rat lumbar DRG neurons to SP (0.3--1 microM). At 1 microM, SP increased the excitability of 'small', putative nociceptive neurons but had little effect on the excitability of 'large' neurons. Two-four weeks after sciatic nerve section, however, the effect of SP on 'large' axotomized neurons was increased and its effect on 'small' neurons was decreased. SP did not affect Ca(2+) channel currents in control or axotomized neurons. The effects of SP on the current-voltage (I--V) relationship of 77% of neurons involved increased inward current at potentials below -30 mV and suppressed outward current at potentials above -20 mV. The effects of SP on the I--V relationship were similar in control and in axotomized neurons and the altered sensitivity of 'small' and 'large' cells could not be attributed to axotomy-induced changes in input resistance or membrane potential. The possible relevance of alterations in sensitivity, of 'large' DRG neurons to SP, to the generation of neuropathic pain is discussed.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009437	Neuralgia	Intense or aching pain that occurs along the course or distribution of a peripheral or cranial nerve.	Nerve Pain,Neurodynia,Paroxysmal Nerve Pain,Neuralgia, Atypical,Neuralgia, Iliohypogastric Nerve,Neuralgia, Ilioinguinal,Neuralgia, Perineal,Neuralgia, Stump,Neuralgia, Supraorbital,Neuralgia, Vidian,Neuropathic Pain,Atypical Neuralgia,Atypical Neuralgias,Iliohypogastric Nerve Neuralgia,Iliohypogastric Nerve Neuralgias,Ilioinguinal Neuralgia,Ilioinguinal Neuralgias,Nerve Neuralgia, Iliohypogastric,Nerve Neuralgias, Iliohypogastric,Nerve Pain, Paroxysmal,Nerve Pains,Nerve Pains, Paroxysmal,Neuralgias,Neuralgias, Atypical,Neuralgias, Iliohypogastric Nerve,Neuralgias, Ilioinguinal,Neuralgias, Perineal,Neuralgias, Stump,Neuralgias, Supraorbital,Neuralgias, Vidian,Neurodynias,Neuropathic Pains,Pain, Nerve,Pain, Neuropathic,Pain, Paroxysmal Nerve,Pains, Nerve,Pains, Neuropathic,Pains, Paroxysmal Nerve,Paroxysmal Nerve Pains,Perineal Neuralgia,Perineal Neuralgias,Stump Neuralgia,Stump Neuralgias,Supraorbital Neuralgia,Supraorbital Neuralgias,Vidian Neuralgia,Vidian Neuralgias
D009475	Neurons, Afferent	Neurons which conduct NERVE IMPULSES to the CENTRAL NERVOUS SYSTEM.	Afferent Neurons,Afferent Neuron,Neuron, Afferent
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D005727	Ganglia, Spinal	Sensory ganglia located on the dorsal spinal roots within the vertebral column. The spinal ganglion cells are pseudounipolar. The single primary branch bifurcates sending a peripheral process to carry sensory information from the periphery and a central branch which relays that information to the spinal cord or brain.	Dorsal Root Ganglia,Spinal Ganglia,Dorsal Root Ganglion,Ganglion, Spinal,Ganglia, Dorsal Root,Ganglion, Dorsal Root,Spinal Ganglion
D000200	Action Potentials	Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.	Spike Potentials,Nerve Impulses,Action Potential,Impulse, Nerve,Impulses, Nerve,Nerve Impulse,Potential, Action,Potential, Spike,Potentials, Action,Potentials, Spike,Spike Potential
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001464	Barium	An element of the alkaline earth group of metals. It has an atomic symbol Ba, atomic number 56, and atomic weight 138. All of its acid-soluble salts are poisonous.
D012584	Sciatic Nerve	A nerve which originates in the lumbar and sacral spinal cord (L4 to S3) and supplies motor and sensory innervation to the lower extremity. The sciatic nerve, which is the main continuation of the sacral plexus, is the largest nerve in the body. It has two major branches, the TIBIAL NERVE and the PERONEAL NERVE.	Nerve, Sciatic,Nerves, Sciatic,Sciatic Nerves
D013373	Substance P	An eleven-amino acid neurotransmitter that appears in both the central and peripheral nervous systems. It is involved in transmission of PAIN, causes rapid contractions of the gastrointestinal smooth muscle, and modulates inflammatory and immune responses.	Euler-Gaddum Substance P,Hypothalamic Substance P,SP(1-11),Euler Gaddum Substance P,Substance P, Euler-Gaddum,Substance P, Hypothalamic