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Transient receptor potential vanilloid type 1 receptor regulates glutamatergic synaptic inputs to the spinothalamic tract neurons of the spinal cord deep dorsal horn.
Neuroscience. 2009 May 05; 160(2):508-16.N

Abstract

The spinothalamic tract (STT) neurons in the spinal dorsal horn play an important role in transmission and processing of nociceptive sensory information. Although transient receptor potential vanilloid type 1 (TRPV1) receptors are present in the spinal cord dorsal horn, their physiological function is not fully elucidated. In this study, we examined the role of TRPV1 in modulating neuronal activity of the STT neurons through excitatory and inhibitory synaptic inputs. Whole-cell patch-clamp recordings were performed on STT neurons labeled by a retrograde fluorescent tracer injected into the ventral posterior lateral (VPL) nucleus of the thalamus. Capsaicin (1 microM) increased the frequency of miniature excitatory postsynaptic currents (mEPSC) without changing the amplitude or decay time constant of mEPSC. In contrast, capsaicin had no distinct effect on GABAergic miniature inhibitory postsynaptic currents (mIPSC). Capsazepine (10 microM), a TRPV1 receptor antagonist, abolished the effect of capsaicin on mEPSCs. Capsazepine itself did not affect the baseline amplitude and frequency of mEPSC. The effect of capsaicin on mEPSC was also abolished by removal of external Ca(2+), but not by treatment with Cd(2+). Furthermore, capsaicin increased the firing activity of the STT neurons and this increase in neuronal activity by capsaicin was abolished in the presence of non-N-methyl-d-aspartic acid (NMDA) and NMDA receptor antagonists, 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo[f]quinoxaline-2,3-dione (NBQX) and (R)-amino-5-phosphonovaleric acid (APV). These data suggest that activation of TRPV1 potentiates the glutamate release from excitatory terminals of primary afferent fibers and subsequently increases the neural activity of STT neurons of the rat spinal cord deep dorsal horn.

Authors+Show Affiliations

Department of Physiology, Seoul National University College of Medicine, 28 Yungundong Jongnogu, Seoul 110-799, Korea.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

19236908

Citation

Kim, H, et al. "Transient Receptor Potential Vanilloid Type 1 Receptor Regulates Glutamatergic Synaptic Inputs to the Spinothalamic Tract Neurons of the Spinal Cord Deep Dorsal Horn." Neuroscience, vol. 160, no. 2, 2009, pp. 508-16.
Kim H, Cui L, Kim J, et al. Transient receptor potential vanilloid type 1 receptor regulates glutamatergic synaptic inputs to the spinothalamic tract neurons of the spinal cord deep dorsal horn. Neuroscience. 2009;160(2):508-16.
Kim, H., Cui, L., Kim, J., & Kim, S. J. (2009). Transient receptor potential vanilloid type 1 receptor regulates glutamatergic synaptic inputs to the spinothalamic tract neurons of the spinal cord deep dorsal horn. Neuroscience, 160(2), 508-16. https://doi.org/10.1016/j.neuroscience.2009.02.019
Kim H, et al. Transient Receptor Potential Vanilloid Type 1 Receptor Regulates Glutamatergic Synaptic Inputs to the Spinothalamic Tract Neurons of the Spinal Cord Deep Dorsal Horn. Neuroscience. 2009 May 5;160(2):508-16. PubMed PMID: 19236908.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Transient receptor potential vanilloid type 1 receptor regulates glutamatergic synaptic inputs to the spinothalamic tract neurons of the spinal cord deep dorsal horn. AU - Kim,H, AU - Cui,L, AU - Kim,J, AU - Kim,S J, Y1 - 2009/02/21/ PY - 2009/01/31/received PY - 2009/02/09/revised PY - 2009/02/10/accepted PY - 2009/2/25/entrez PY - 2009/2/25/pubmed PY - 2009/10/22/medline SP - 508 EP - 16 JF - Neuroscience JO - Neuroscience VL - 160 IS - 2 N2 - The spinothalamic tract (STT) neurons in the spinal dorsal horn play an important role in transmission and processing of nociceptive sensory information. Although transient receptor potential vanilloid type 1 (TRPV1) receptors are present in the spinal cord dorsal horn, their physiological function is not fully elucidated. In this study, we examined the role of TRPV1 in modulating neuronal activity of the STT neurons through excitatory and inhibitory synaptic inputs. Whole-cell patch-clamp recordings were performed on STT neurons labeled by a retrograde fluorescent tracer injected into the ventral posterior lateral (VPL) nucleus of the thalamus. Capsaicin (1 microM) increased the frequency of miniature excitatory postsynaptic currents (mEPSC) without changing the amplitude or decay time constant of mEPSC. In contrast, capsaicin had no distinct effect on GABAergic miniature inhibitory postsynaptic currents (mIPSC). Capsazepine (10 microM), a TRPV1 receptor antagonist, abolished the effect of capsaicin on mEPSCs. Capsazepine itself did not affect the baseline amplitude and frequency of mEPSC. The effect of capsaicin on mEPSC was also abolished by removal of external Ca(2+), but not by treatment with Cd(2+). Furthermore, capsaicin increased the firing activity of the STT neurons and this increase in neuronal activity by capsaicin was abolished in the presence of non-N-methyl-d-aspartic acid (NMDA) and NMDA receptor antagonists, 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo[f]quinoxaline-2,3-dione (NBQX) and (R)-amino-5-phosphonovaleric acid (APV). These data suggest that activation of TRPV1 potentiates the glutamate release from excitatory terminals of primary afferent fibers and subsequently increases the neural activity of STT neurons of the rat spinal cord deep dorsal horn. SN - 1873-7544 UR - https://www.unboundmedicine.com/medline/citation/19236908/Transient_receptor_potential_vanilloid_type_1_receptor_regulates_glutamatergic_synaptic_inputs_to_the_spinothalamic_tract_neurons_of_the_spinal_cord_deep_dorsal_horn_ DB - PRIME DP - Unbound Medicine ER -