Platelet-activating factor and somatostatin activate mitogen-activated protein kinase (MAP kinase) and arachidonate release.

Platelet-activating factor (PAF) receptor and somatostatin receptor (SSTR4) were cloned, and their primary structures were identified. They are both highly expressed in the rat hippocampus. When expressed in Chinese hamster ovary cells, these receptors activated mitogen-activated protein (MAP) kinase cascade and phospholipase A2. Arachidonic acid or its derivatives, thus produced by the activation of these receptors may play some roles in synaptic transmission and synaptic plasticity.