Morphology and serotonergic innervation of physiologically identified cells of the guinea pig's myenteric plexus

摘要: Ganglion cells of the myenteric plexus guinea pig were physiologically classified as to cell type using intracellular microelectrodes containing horseradish peroxidase (HRP). Interganglionic fiber tracts then stimulated in an attempt elicit slow excitatory postsynaptic potentials (EPSPs) impaled cells. The presence or absence a EPSP was noted, following which injected with HRP through recording micropipette and finally incubated tritiated 5- hydroxytryptamine ([3H]-5-HT; 0.5 microM) desmethylimipramine (10 nM). preparations examined by light electron microscopy (EM) for identified, HRP-injected neurons demonstrated histochemically serotonergic nerve terminals simultaneously radioautographically. Forty-seven HRP, studied microscopy. Of these, 22 also fully analyzed sample included 13 I/S (6 microscopic radioautography), 16 II/AH 18 nonspiking (NS) radioautography). Slow EPSPs only observed All five subset that manifested contacted terminals. These found on 7 10 cells, 2 6 0 NS Serotonergic terminals, therefore, (p less than 0.05) especially those showed 0.005) more frequently other types ganglion Morphologically, short, stubby dendrites reproducibly be glia could recognized their astrocytic appearance; however, shape did not otherwise correlate physiological type. data are compatible provide support hypothesis 5-HT is one mediators plexus.