A phosphoinositide-linked peptide response in cultured rat astrocytes was studied by measuring the accumulation of [3H]inositol phosphates in the presence of lithium. Cultures derived from cortex, cerebellum and spinal cord each showed a unique pattern or degree of stimulation to a panel of neuropeptides. Cortical and cerebellar astrocytes were similar, responding to bradykinin, oxytocin, vasopressin, eledoisin and neurokinin beta, whereas spinal cord astrocytes were stimulated by substance P, bradykinin, eledoisin, and neurokinins alpha and beta. These observations are evidence in favour of regional specialisations of astrocytes which may respond uniquely to peptides released by particular populations of neurons.