Functional Distribution of Nicotinic Receptors in CA3 Region of the Hippocampus

• Published in: Journal of molecular neuroscience 2010-01, Vol.40 (1-2), p.114-120
• Main Authors: Grybko, Michael, Sharma, Geeta, Vijayaraghavan, Sukumar
• Format: Article
• Language: English
• Subjects: Acetylcholine - metabolism; alpha7 Nicotinic Acetylcholine Receptor; Animals; Astrocytes - cytology; Astrocytes - metabolism; Biomedical and Life Sciences; Biomedicine; CA3 Region, Hippocampal - cytology; CA3 Region, Hippocampal - metabolism; Calcium - analysis; Calcium - metabolism; Cell Biology; Dentate Gyrus - cytology; Dentate Gyrus - metabolism; Fluorescent Dyes; Fura-2 - analogs & derivatives; Glutamic Acid - metabolism; Glutamic Acid - secretion; Indicators and Reagents; Mossy Fibers, Hippocampal - metabolism; Mossy Fibers, Hippocampal - ultrastructure; Neurochemistry; Neurology; Neurons; Neurosciences; Nicotine; Organ Culture Techniques; Presynaptic Terminals - metabolism; Presynaptic Terminals - secretion; Presynaptic Terminals - ultrastructure; Proteomics; Pyramidal Cells - cytology; Pyramidal Cells - metabolism; Rats; Rats, Sprague-Dawley; Receptors, Nicotinic - analysis; Receptors, Nicotinic - metabolism; Staining and Labeling - methods; Synaptic Transmission - physiology
• ISSN: 0895-8696; 1559-1166
• DOI: 10.1007/s12031-009-9266-8

Nicotinic acetylcholine receptor (nAChR) modulation of a number of parameters of synaptic signaling in the brain has been demonstrated. It is likely that effects of nicotine are due to its ability to modulate network excitability as a whole. A pre-requisite to understanding the effects of nicotine on network properties is the elucidation of functional receptors. We have examined the distribution of functional nAChRs in the dentate gyrus granule cells and the CA3 region of the mammalian hippocampus using calcium imaging from acute slices. Our results demonstrate the presence of functional nAChRs containing the α7 subunit (α7-nAChRs) on mossy fiber boutons, CA3 pyramidal cells, and on astrocytes. In addition, both CA3 interneurons and granule cells show nicotinic signals. Our study suggests that functional nicotinic receptors are widespread in their distribution and that calcium imaging might be an effective technique to examine locations of these receptors in the mammalian brain.