HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Yamaguchi, K Articles by Stanfield, P R Search for Related Content PubMed PubMed Citation Articles by Yamaguchi, K Articles by Stanfield, P R

Department of Biological Sciences, Purdue University, West Lafayette, IN 47907.

1. Whole-cell recording was used to investigate the effects of substance P on cultured neurones from the rat nucleus basalis. 2. Brief applications of substance P produced a reduction, about 1 min in duration, of resting membrane conductance. The concentration producing a half-maximal effect was approximately 40 nM, with the continuous presence of substance P resulting in desensitization of the response. 3. The control current-voltage relation exhibited inward rectification over the voltage range -70 to -150 mV, and hyperpolarization produced a time-dependent decrease of current (inactivation). 4. The substance P-sensitive current, obtained by subtracting the current during the presence of the tachykinin from the control current, showed no time-dependent inactivation, though its current-voltage relation also revealed inward rectification, with the reversal potential being approximately equal to the potassium equilibrium potential, Vk. 5. The relation between the substance P-sensitive chord conductance and voltage could be fitted by a Boltzmann equation, with changes in [K+]o shifting this relation along the voltage axis roughly in parallel with the shift in Vk. The maximum conductance was proportional to [( K+]o). 6. Cs+ (0.1 mM) blocked the substance P-sensitive current in a voltage-dependent manner, with an equivalent valency for Cs+ of 1.9. Barium blockage of the substance P-sensitive current was less voltage dependent. 7. Replacement of external Na+ by tetramethylammonium (TMA+) ions reduced the substance P-sensitive current by only 18%. 8. These results indicate that substance P inhibits potassium channels with inward rectifier properties very similar to those of skeletal muscle. 9. Application of sodium nitroprusside did not alter the effect of substance P, suggesting that cyclic GMP plays no role in the channel modulation.

This article has been cited by other articles:

				Y. Kang, Y. Dempo, A. Ohashi, M. Saito, H. Toyoda, H. Sato, H. Koshino, Y. Maeda, and T. Hirai Nitric Oxide Activates Leak K+ Currents in the Presumed Cholinergic Neuron of Basal Forebrain J Neurophysiol, December 1, 2007; 98(6): 3397 - 3410. [Abstract] [Full Text] [PDF]

				T. G. J. Allen and D. A. Brown Modulation of the excitability of cholinergic basal forebrain neurones by KATP channels J. Physiol., January 15, 2004; 554(2): 353 - 370. [Abstract] [Full Text] [PDF]

				D. Bajic, M. Koike, A. M. Albsoul-Younes, S. Nakajima, and Y. Nakajima Two different inward rectifier K+ channels are effectors for transmitter-induced slow excitation in brain neurons PNAS, October 29, 2002; 99(22): 14494 - 14499. [Abstract] [Full Text] [PDF]

				J. A. Sim and T.G.J. Allen Morphological and Membrane Properties of Rat Magnocellular Basal Forebrain Neurons Maintained in Culture J Neurophysiol, October 1, 1998; 80(4): 1653 - 1669. [Abstract] [Full Text] [PDF]

				E. N. Yamoah, L. Matzel, and T. Crow Expression of Different Types of Inward Rectifier Currents Confers Specificity of Light and Dark Responses in Type A and B Photoreceptors of Hermissenda J. Neurosci., August 15, 1998; 18(16): 6501 - 6511. [Abstract] [Full Text] [PDF]

				K. F. Raab-Graham and C. A. Vandenberg Tetrameric Subunit Structure of the Native Brain Inwardly Rectifying Potassium Channel Kir 2.2 J. Biol. Chem., July 31, 1998; 273(31): 19699 - 19707. [Abstract] [Full Text] [PDF]

				X. Wang and D. Robertson Substance P-Induced Inward Current in Identified Auditory Efferent Neurons in Rat Brain Stem Slices J Neurophysiol, July 1, 1998; 80(1): 218 - 229. [Abstract] [Full Text] [PDF]

				D. E. Garcia, S. Brown, B. Hille, and K. Mackie Protein Kinase C Disrupts Cannabinoid Actions by Phosphorylation of the CB1 Cannabinoid Receptor J. Neurosci., April 15, 1998; 18(8): 2834 - 2841. [Abstract] [Full Text] [PDF]

				Y. J. Liao, Y. N. Jan, and L. Y. Jan Heteromultimerization of G-Protein-Gated Inwardly Rectifying K+ Channel Proteins GIRK1 and GIRK2 and Their Altered Expression in weaver Brain J. Neurosci., November 15, 1996; 16(22): 7137 - 7150. [Abstract] [Full Text] [PDF]

				T. Aosaki and Y. Kawaguchi Actions of Substance P on Rat Neostriatal Neurons In Vitro J. Neurosci., August 15, 1996; 16(16): 5141 - 5153. [Abstract] [Full Text] [PDF]