 |
||||
|
||||
|
||||
|
||||
Previous Article | Next Article
The Journal of Neuroscience, April 15, 2002, 22(8):2998-3004
Opioid Peptides Inhibit Excitatory But Not Inhibitory Synaptic Transmission in the Rat Dorsal Motor Nucleus of the Vagus
Kirsteen N. Browning1, Alexander E. Kalyuzhny2, and R. Alberto Travagli1 1 Division of Gastroenterology and Department of Physiology, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0682, and 2 Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455
Opioid peptides produce gastrointestinal inhibition and increase feeding when applied to the brainstem. The present studies were designed to determine the actions of opioid peptides on synaptic transmission within the dorsal motor nucleus of the vagus (DMV) and the localization of µ-opioid receptors. Whole-cell recordings were made from identified gastrointestinal-projecting DMV neurons in thin brainstem slices of the rat. Electrical stimulation of the nucleus of the tractus solitarius evoked EPSCs and IPSCs. In all neurons tested, methionine (Met)-enkephalin (0.003-30 µM) inhibited the peak amplitude of the EPSCs. The effect was prevented by naloxone (1 µM) as well as by naloxonazine (0.2 µM). An increase in the ratio of the evoked paired pulses indicated that the inhibition was attributable to actions at presynaptic receptors. This presynaptic inhibitory action was mimicked by [D-Ala2, N-Me-Phe4, Gly5-ol]-enkephalin (0.1 µM) and the analgesic dipeptide kyotorphin (10 µM) but not by cyclic[D-Pen2, D-Pen5]-enkephalin (1 µM) and trans-3,4-dichloro-N-methyl-N-[2-(1-pyrrolidinyl)-cyclohexyl]benzeneacetamide methanesulfonate (1 µM). In contrast, the amplitude of evoked IPSCs was not altered either by Met-enkephalin or by any of the opioid receptor-selective agonists. Immunohistochemical studies revealed that nerve terminals apposing DMV neurons showed immunoreactivity to µ-opioid receptors colocalized with glutamate immunoreactivity but not glutamic acid decarboxylase immunoreactivity. These results suggest that within the DMV, µ-opioid receptors are present on the nerve terminals of excitatory but not inhibitory inputs to GI motoneurons. Such specificity may imply that the central inhibitory action of opioid peptides on gastrointestinal function targets selected pathways.
Key words: dorsal motor nucleus of the vagus; opioids; dorsal vagal complex; gastrointestinal function; immunoreactivity; feeding
Copyright © 2002 Society for Neuroscience 0270-6474/02/2282998-07$05.00/0
This article has been cited by other articles:
T. W. Bailey, S. M. Appleyard, Y.-H. Jin, and M. C. Andresen
Organization and Properties of GABAergic Neurons in Solitary Tract Nucleus (NTS)
J Neurophysiol, April 1, 2008; 99(4): 1712 - 1722.
[Abstract] [Full Text] [PDF]
S. L. Poole, J. Deuchars, D. I. Lewis, and S. A. Deuchars
Subdivision-Specific Responses of Neurons in the Nucleus of the Tractus Solitarius to Activation of Mu-Opioid Receptors in the Rat
J Neurophysiol, November 1, 2007; 98(5): 3060 - 3071.
[Abstract] [Full Text] [PDF]
N. R. Glatzer, A. V. Derbenev, B. W. Banfield, and B. N. Smith
Endomorphin-1 Modulates Intrinsic Inhibition in the Dorsal Vagal Complex
J Neurophysiol, September 1, 2007; 98(3): 1591 - 1599.
[Abstract] [Full Text] [PDF]
K. N. Browning and R. A. Travagli
Functional Organization of Presynaptic Metabotropic Glutamate Receptors in Vagal Brainstem Circuits
J. Neurosci., August 22, 2007; 27(34): 8979 - 8988.
[Abstract] [Full Text] [PDF]
R. L. Young, A. J. Page, T. A. O'Donnell, N. J. Cooper, and L. A. Blackshaw
Peripheral versus central modulation of gastric vagal pathways by metabotropic glutamate receptor 5
Am J Physiol Gastrointest Liver Physiol, February 1, 2007; 292(2): G501 - G511.
[Abstract] [Full Text] [PDF]
K. N. Browning, Z. Zheng, T. W. Gettys, and R. A. Travagli
Vagal afferent control of opioidergic effects in rat brainstem circuits
J. Physiol., September 15, 2006; 575(3): 761 - 776.
[Abstract] [Full Text] [PDF]
K. N. Browning, F. H. Coleman, and R. A. Travagli
Effects of pancreatic polypeptide on pancreas-projecting rat dorsal motor nucleus of the vagus neurons
Am J Physiol Gastrointest Liver Physiol, August 1, 2005; 289(2): G209 - G219.
[Abstract] [Full Text] [PDF]
N. R. Glatzer and B. N. Smith
Modulation of Synaptic Transmission in the Rat Nucleus of the Solitary Tract by Endomorphin-1
J Neurophysiol, May 1, 2005; 93(5): 2530 - 2540.
[Abstract] [Full Text] [PDF]
G. E. Hermann, J. S. Nasse, and R. C. Rogers
{alpha}-1 adrenergic input to solitary nucleus neurones: calcium oscillations, excitation and gastric reflex control
J. Physiol., January 15, 2005; 562(2): 553 - 568.
[Abstract] [Full Text] [PDF]
G. Grabauskas, S.-Y. Zhou, S. Das, Y. Lu, C. Owyang, and H. C Moises
Prolactin-releasing peptide affects gastric motor function in rat by modulating synaptic transmission in the dorsal vagal complex
J. Physiol., December 15, 2004; 561(3): 821 - 839.
[Abstract] [Full Text] [PDF]
A. V. Derbenev, T. C. Stuart, and B. N. Smith
Cannabinoids suppress synaptic input to neurones of the rat dorsal motor nucleus of the vagus nerve
J. Physiol., September 15, 2004; 559(3): 923 - 938.
[Abstract] [Full Text] [PDF]
K. N. Browning, A. E. Kalyuzhny, and R. A. Travagli
{micro}-Opioid Receptor Trafficking on Inhibitory Synapses in the Rat Brainstem
J. Neurosci., August 18, 2004; 24(33): 7344 - 7352.
[Abstract] [Full Text] [PDF]
J. Wallden, S.-E. Thorn, and M. Wattwil
The Delay of Gastric Emptying Induced by Remifentanil Is Not Influenced by Posture
Anesth. Analg., August 1, 2004; 99(2): 429 - 434.
[Abstract] [Full Text] [PDF]
M. Tatewaki, M. Harris, K. Uemura, T. Ueno, E. Hoshino, A. Shiotani, T. N. Pappas, and T. Takahashi
Dual effects of acupuncture on gastric motility in conscious rats
Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2003; 285(4): R862 - R872.
[Abstract] [Full Text] [PDF]
S. F. Davis, K. W. Williams, W. Xu, N. R. Glatzer, and B. N. Smith
Selective Enhancement of Synaptic Inhibition by Hypocretin (Orexin) in Rat Vagal Motor Neurons: Implications for Autonomic Regulation
J. Neurosci., May 1, 2003; 23(9): 3844 - 3854.
[Abstract] [Full Text] [PDF]
R. A. Travagli, G. E. Hermann, K. N. Browning, and R. C. Rogers
Musings on the Wanderer: What's New in our Understanding of Vago-Vagal Reflexes?: III. Activity-dependent plasticity in vago-vagal reflexes controlling the stomach
Am J Physiol Gastrointest Liver Physiol, February 1, 2003; 284(2): G180 - G187.
[Abstract] [Full Text] [PDF]
|
|
|
|
 |
|