On June 17, 2009, the Journal of Neuroscience published a research article entitled "Activation of phosphatidylinositol-linked D1-like receptor modulates FGF-2 expression in astrocytes via IP3-dependent Ca2+ signaling". This work was carried out by Xin-hua Zhang, Zheng Zhou and other co-workers from the laboratory of Dr. Jia-wei Zhou at ION, in close collaboration with Dr. Xue-chu Zhen at Shanghai Institute of Materia Medica.

FGF-2 is a potent growth factor that is essential for cell proliferation and growth of a variety of cell types in brain. It is predominantly synthesized and secreted by astrocytes in the adult brain. Stringent regulation of its biosynthesis and release is thus required for the development and maintenance of the central nervous system. However, how FGF-2 expression is regulated in astrocytes remains largely unknown. In this study, the authors showed that activation of PI-linked D1-like receptor promotes FGF-2 levels in astrocyte occurs via elevating intracellular calcium levels. In contrast, activation of classical dopamine receptors had opposite effects on intracellular calcium levels. Moreover, they found a remarkable modulatory effect of glutamate on FGF-2 expression through induction of calcium influx, implying another interesting function of glutamate in regulating astrocyte activity. These findings demonstrates that neurotransmitters dopamine, glutamate and a ligand(s) for PI-linked D1-like receptor are the major players in maintaining FGF-2 expression in astrocytes within the normal range under physiological conditions. Ligands for PI-linked D1-like receptor may be useful for enhancing FGF-2 levels in the brain of patients with Parkinson’s disease through promoting neuronal survival.