Electrophysiological classification of submucosal plexus neurones in the jejunum of the newborn pig.
Intracellular recordings were made from the internal and external submucosal ganglia of the porcine small intestine and neuronal properties were classified using two existing schemes for guinea-pig enteric neurones. In the first analysis, 77% of cells were designated as Type 4 since they were a heterogeneous population of neurones with the overlapping properties of S/Type 1 and AH/Type 2. The simplicity and usefulness of the second classification scheme was due to its emphasis on a single electrophysiological event, namely, the long-lasting after-hyperpolarization (AH) following the action potential. Eighty-eight percent of the cells studied were thus categorized as either AH (with an AH) or S (without an AH). All S neurones displayed fast synaptic potentials in response to stimulation of interganglionic fibre strands. AH neurones were subdivided into two groups dependent on whether they received fast synaptic inputs. Only by employing the second scheme of classification were differences in the neuronal characteristics and synaptic profiles between the two submucosal plexuses detected. It is concluded that the S and AH system of classification is the most appropriate method for the analysis of intracellular recordings from submucosal neurones in the porcine small intestine.
Thomsen
L
L
Institute of Anatomy and Physiology, Royal Veterinary and Agricultural University, Copenhagen, Denmark.
Pearson
G T
GT
Skadhauge
E
E
D000818:Animals; D000831:Animals, Newborn; D005260:Female; D007583:Jejunum / Q000294:innervation*; D008564:Membrane Potentials / Q000502:physiology; D009474:Neurons / Q000145:classification / Q000502:physiology*; D013368:Submucous Plexus / Q000166:cytology / Q000502:physiology*; D013552:Swine / Q000033:anatomy & histology / Q000502:physiology*