Glial-neuronal interactions--implications for plasticity and drug addiction.
Among neuroscientists, astrocytes have for long played Cinderella to their neuron stepsisters. While the importance of glia in regulating brain activity was predicted by Ramon y Cajal more than a century ago (Garcia-Marin et al., Trends. Neurosci. 30:479-787, 2007), these cells, until recently, have been thought to play mainly a passive part in synaptic signaling. Results obtained over the last decade have begun to suggest otherwise. Experiments carried out in a number of labs have shown that glial cells, especially astrocytes, directly participate in synaptic signaling and potentially regulate synaptic plasticity and network excitability. The presence of signaling pathways on astrocytes that are analogous to those at presynaptic terminals suggests a role for these cells in network plasticity. Findings that the same signaling pathways can be activated by receptors for drugs of abuse present on astrocytes suggest a role for these cells in the addictive process. In this review, we summarize current understanding of astrocytic role in synaptic signaling and suggest that a complete understanding of the process of addiction requires a better understanding of the functional role of these cells.
Vijayaraghavan
Sukumar
S
Department of Physiology and Biophysics and the Neuroscience Program, University of Colorado, Denver, School of Medicine, Anschutz Medical Campus, MS 8307, P18-7121, Aurora, Colorado 80045, USA. Sukumar.v@uchsc.edu
D000255:Adenosine Triphosphate / Q000502:physiology; D000818:Animals; D001253:Astrocytes / Q000502:physiology; D020013:Calcium Signaling; D002450:Cell Communication; D002560:Cerebrovascular Circulation; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000187:drug effects / Q000235:genetics; D017629:Gap Junctions / Q000502:physiology; D006801:Humans; D008322:Mammals; D008833:Microcirculation; D009457:Neuroglia / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D018377:Neurotransmitter Agents / Q000502:physiology; D011955:Receptors, Drug / Q000502:physiology; D043562:Receptors, G-Protein-Coupled; D019966:Substance-Related Disorders / Q000503:physiopathology*; D009435:Synaptic Transmission / Q000502:physiology; D014666:Vasomotor System / Q000502:physiology
D029721:Drosophila Proteins; D018377:Neurotransmitter Agents; D011955:Receptors, Drug; D043562:Receptors, G-Protein-Coupled; C542235:moody protein, Drosophila; D000255:Adenosine Triphosphate