Astrocyte response to glutamatergic stimulation is enhanced by dopamine in a compartmental model of astrocytes

Astrocytes are active cells that respond to neurotransmitters with elevations in their intracellular calcium (Ca2+) concentration (Ca2+ signals). In a tripartite synapse involving two neurons coupled by a glutamatergic synapse and one astrocyte, glutamate released by the presynaptic neuron can generate Ca2+ signals in the astrocyte, which in turn trigger the release of neuroactive molecules (gliotransmitters) by the astrocyte that bind to receptors in the pre- and postsynaptic neuron membranes and modulate synaptic transmission. Astrocytic Ca2+ signals can also be evoked by dopamine released in distant sites.