Inhibitory neurotransmission in the circular muscle layer of mouse colon

N. J. Spencer, R. A.R. Bywater, M. E. Holman, G. S. Taylor

Research output: Contribution to journalArticlepeer-review

39 Citations (Scopus)

Abstract

Intracellular electrophysiological techniques were used to record the spontaneous myoelectric activity in the circular muscle layer of an in vitro preparation of whole mouse colon. In 34 out of 58 preparations, spontaneous depolarisations (myoelectric complexes, MCs) were recorded cyclically, about every 4 min. In these preparations, apamin (250 nM) and N(G)-nitro-L-arginine (NOLA, 100 μM) depolarised the membrane potential between MCs by 8 mV or 13 mV, respectively. Tetrodotoxin (1.6 μM) abolished MCs and also induced depolarisation (17 mV). In the remaining 24 preparations. MCs were not recorded and the membrane potential was significantly depolarised compared to the membrane potential between MCs. NOLA (100 μM), apamin (250 nM) and tetrodotoxin (1.6 μM) were without significant effect on membrane potential. It is suggested that in preparations that exhibit MC cycling, membrane potential between MCs is maintained in a state of tonic inhibition, predominantly mediated by nitrergic mechanisms generated via spontaneously active inhibitory neurons. Apamin-sensitive channels may also be involved in the inhibition.

Original languageEnglish
Pages (from-to)10-14
Number of pages5
JournalJournal of the Autonomic Nervous System
Volume70
Issue number1-2
DOIs
Publication statusPublished - 28 May 1998
Externally publishedYes

Keywords

  • Apamin
  • Mouse colon
  • Myoelectric complex (MC)

Fingerprint Dive into the research topics of 'Inhibitory neurotransmission in the circular muscle layer of mouse colon'. Together they form a unique fingerprint.

Cite this