{"id": "package:3dd83230-3d56-4c17-bd13-7110f9ae2469", "name": "PIIS2352345X21001831.pdf", "self_uri": "https://services.scicrunch.io/sparc/drs/v1/objects/3dd83230-3d56-4c17-bd13-7110f9ae2469", "size": 8864849, "created_time": "2021-12-21T23:47:25,259631Z", "updated_time": "2021-12-21T23:47:28,212342Z", "version": "1", "mime_type": "application/pdf", "checksums": [{"checksum": "26afcfb9658b8510a64eb345b75d8f8afc76ad1076e3177097f3afade63bd6ff", "type": "sha256"}], "access_methods": [{"type": "s3", "access_url": {"url": "s3://prd-sparc-discover50-use1/368/files/docs/PIIS2352345X21001831.pdf"}, "region": "us-east-1"}], "dataset": {"id": "368", "doi": "DOI:10.26275/yv7l-9fst", "title": "Synaptic components function and modulation characterized by GCaMP6f calcium imaging in cholinergic myenteric ganglion neurons", "description": "Synapses and their components on myenteric neurons assessed by GCaMP Ca2+ imaging", "abstract": "Experiments with selective receptor agonists and antagonists reveal that most colonic cholinergic (i.e. GCaMP6f+/ChAT+) MG neurons express nicotinic ACh receptors (nAChRs) and most express ionotropic serotonin receptors (5-HT3Rs). Cholinergic MG neurons also display small, spontaneous Ca2+ transients occurring at ≈ 0.2 Hz.  Experiments with inhibitors of Na+ channel dependent impulses, presynaptic Ca2+ channels and postsynaptic receptor function reveal that the Ca2+ transients arise from impulse-driven presynaptic activity and subsequent activation of postsynaptic nAChRs or 5-HT3Rs.   Electrical stimulation of MP longitudinal connectives evoked Ca2+ responses that similarly depended on nAChRs and/or 5-HT3Rs.  Responses to single connective stimuli had peak amplitudes and rise and decay times that were indistinguishable from the spontaneous Ca2+ transients and the largest fraction had synaptic delays < 4 ms, consistent with activation by monosynaptic inputs.  These results indicate that the spontaneous Ca2+ transients and stimulus evoked Ca2+ responses originate from circuits involving fast chemical synaptic transmission mediated by nAChRs and/or 5-HT3Rs.  Experiments with an 7-nAChR agonist and antagonist, and with pituitary adenylate cyclase activating polypeptide (PACAP) reveal that the same synaptic circuits display extensive capacity for presynaptic modulation.  Our use of non-invasive GCaMP6f/ChAT Ca2+ imaging in colon segments with intrinsic connections preserved, reveals an abundance of direct and modulatory synaptic influences on cholinergic MG neurons."}}