Sources of excitatory synaptic inputs to neurochemically identified submucous neurons of guinea-pig small intestine

J. C. Bornstein, J. B. Furness, M. Costa

Research output: Contribution to journalArticle

57 Citations (Scopus)

Abstract

The locations of the cell bodies of axons responsible for synaptic potentials evoked in neurochemically identified submucous neurons of the guinea-pig small intestine were investigated using a combination of intracellular recording, immunohistochemical and lesioning techniques. The myenteric plexus was removed from an 8-15 mm wide ring of small intestine in 15 anaesthetized guinea-pigs. After the operations, the animals were allowed to recover for 3-7 days so that nerve terminals that were disconnected from their cell bodies would degenerate. Preparations of submucous plexus were then made from the region under the lesion. Submucous neurons were impaled with electrodes containing a mixture of KC1 and the fluorescent dye, Lucifer yellow CH, and their electrophysiological properties determined. They were then filled with the dye for subsequent reidentification after processing for immunohistochemical localization of vasoactive intestinal peptide (VIP) and neuropeptide Y (NPY). The synaptic inputs to 33 neurons were characterized: 19 of these were found to be VIP-reactive, 7 were NPY-reactive and 7 were negative for both VIP and NPY. These results were compared to those obtained from 43 neurons in control preparations: 25 VIP-reactive, 9 NPY-reactive and 9 negative for both VIP and NPY. Removal of the myenteric plexus caused a significant reduction in the number of inputs providing fast excitatory synaptic potentials to each of the neurochemically defined classes of neurons. The lesions also caused a significant reduction in the number of VIP-reactive neurons that exhibited slow excitatory synaptic potentials (other neurochemical types do not normally exhibit such responses). In contrast, the number of neurons in which inhibitory synaptic potentials could be evoked was unchanged. It is concluded that many of the excitatory synaptic terminals on submucous neurons originate from cell bodies in the myenteric plexus.

Original languageEnglish
Pages (from-to)83-91
Number of pages9
JournalJournal of the Autonomic Nervous System
Volume18
Issue number1
DOIs
Publication statusPublished - Jan 1987

Keywords

  • Cholinergic neuron
  • Myenteric plexus
  • Neuropeptide Y
  • Slow excitatory potential
  • Submucous plexus
  • Vasoactive intestinal peptide

Fingerprint Dive into the research topics of 'Sources of excitatory synaptic inputs to neurochemically identified submucous neurons of guinea-pig small intestine'. Together they form a unique fingerprint.

  • Cite this