{"id": "package:2eb5c902-50a5-4efd-bd48-684f926f5186", "name": "20180618.1.tif", "self_uri": "https://services.scicrunch.io/sparc/drs/v1/objects/2eb5c902-50a5-4efd-bd48-684f926f5186", "size": 5184000203, "created_time": "2020-09-22T22:37:56,944902Z", "updated_time": "2022-12-13T15:43:03,032359Z", "version": "1", "mime_type": "image/tiff", "checksums": [{"checksum": "37c8984a6140cee2fe4e19c7a2914b0bc32c789ad14de597e7a708a8bc31fb2c", "type": "sha256"}], "access_methods": [{"type": "s3", "access_url": {"url": "s3://prd-sparc-discover50-use1/368/files/primary/sub-29/sam-20180618-1/20180618.1.tif"}, "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."}}