In smooth muscle, cGMP is the signal for relaxation, and is coupled to many homeostatic mechanisms including regulation of vasodilation, vocal tone, insulin secretion, and peristalsis.

It is part of the calcium negative feedback system that is activated in response to the hyperpolarization of the photoreceptors by light.

Activation of GC-C amplifies the excitatory cell response that is modulated by glutamate and acetylcholine receptors.

To be specific, it is found in the somata and dendrites of dopaminergic neurons in the ventral tegmental area (VTA) and the substantia nigra.

sGC expression has been shown to be highest in the striatum compared to other brain regions and has been explored as a possible candidate for restoring striatal dysfunction in Parkinson's disease.

Increased intracellular cGMP has been shown to contribute to excessive neuron excitability and locomotor activity.

Activation of this pathway can also stimulate presynaptic glutamate release and cause an upregulation of AMPA receptors postsynaptically.

Calcium, which plays many roles in the cell and is tightly regulated, disrupts the membrane when it appears in excess.