receptor signaling and physiological effects

Nn on autonomic ganglia

all preganglionic; ACh NT→LGIC for rapid depolarization

Nn on adrenal medulla (chromaffin)

preganglionic; ACh NT→LGIC for catecholamine secretion→stress hormones; symp pathway

M1 on CNS and autonomic ganglia

ACh NT→Gq for neural excitation/ modulation; para pathway

M1 on enteric/gastric pathways

ACh NT→Gq to support enteric/gastric signaling; para pathway

M2

ACh NT→Gi acts on SA/AV node, atria to dec HR, AV conduction, atrial contraction; para pathway

M3 on glands

ACh NT→Gq to cause secretion and inc sweating; symp pathway

M3 on bronchi, GI, bladder, eye, endothelium

ACh NT→Gq to cause smooth muscle contraction; NO cam cause vasodilation para pathway

M4 on CNS

ACh NT→Gi to inhibit neuromodulation; para pathway

M4 on presynaptic sites

ACh NT→Gi to dec NT release in some pathways; para pathway

M5 on CNS

ACh NT→Gq for central modulation; para pathway

M5 on cerebral vascular endo

ACh NT→Gq for cerebral vasodilation; para pathway

A1 on vascular smooth muscle, iris muscle, bladder outlet

NE NT→Gq for contraction to vasoconstrict, dilate pupil, inc bladder outlet resistance; symp pathway

A2 on presynaptic sympathetic terminals

NE NT→Gi to dec NE release; symp pathway

A2 on CNS

NE NT→Gi to dec sympathetic outflow; symp pathway

A2 on pancreatic beta cells

NE NT→Gi to dec insulin release; symp pathway

B1 on heart

NE NT→Gs to inc HR, conduction, contractility; symp pathway

B1 on juxtaglomerular cells

NE NT→Gs to inc renin, symp pathway

B2 on broncial, uterine, some vascular smooth muscle

NE NT→Gs to relax smooth muscle (bronchodilation, uterine relaxation, vasodilation) symp pathway

B3 on adipocytes

NE NT→Gs for lipolysis; symp pathway

B3 on bladder detrusor

NE NT→Gs for detrusor relaxation; symp pathway

cholinergic muscarinic Gq

M1/M2/M3

cholinergic muscarinic Gi

M2/M4

cholinergic nicotinic

Nn, LGIC, stimulatory

adrenergic Gq

A1

adrenergic Gi

A2

adrenergic Gs

B1/B2/B3