title: Functional α7 nicotinic ACh receptors on astrocytes in rat hippocampal CA1 slices.
abstract: Although much is known about the functional expression of the neuronal nicotinic acetylcholine receptors (nAChRs) in various neuronal populations in the brain and elsewhere, much less is known about their expression and functional relevance in glial cells. The expression of functional nAChRs has been reported for cultured astrocytes; however, previous work has failed to detect nAChR-mediated responses in astrocytes in acute slices. In the current study, functional α7 nAChRs on astrocytes in the CA1 region of the rat hippocampus were studied in situ using whole-cell patch-clamp recording and two-photon calcium imaging techniques in acute slices. We found that astrocytes and the chondroitin sulfate proteoglycan NG2-expressing (i.e., NG2) cells did express functional α7 nAChRs. Although the amplitudes of the responses were small, they could be enhanced by the α7-selective positive allosteric modulator PNU-120596. Under these conditions, we found that in comparing the properties of these responses between astrocytes, NG2, and interneurons, there were differences in the kinetics and increases in intracellular calcium levels. This is the first demonstration of functional α7 nAChR-mediated current responses in astrocytes in acute hippocampal slices, data which may shed light on the role of α7 nAChRs in neuroprotection.
authors.affiliation: Department of Physiology, Shantou University Medical College, 22 Xinling Rd, Shantou, Guangdong, 515041, People's Republic of China. jxshen@stu.edu.cn
authors.forename: Jian-xin
authors.initials: JX
authors.lastname: Shen
authors.forename: Jerrel L
authors.initials: JL
authors.lastname: Yakel
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D001253:Astrocytes / Q000502:physiology*; D056547:CA1 Region, Hippocampal / Q000166:cytology* / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D007395:Interneurons / Q000166:cytology / Q000502:physiology; D009924:Organ Culture Techniques; D018408:Patch-Clamp Techniques; D051381:Rats; D011978:Receptors, Nicotinic / Q000502:physiology*; D064569:alpha7 Nicotinic Acetylcholine Receptor
chemical_list: C579165:Chrna7 protein, rat; D011978:Receptors, Nicotinic; D064569:alpha7 Nicotinic Acetylcholine Receptor; D002118:Calcium