Cholinergic modulation amplifies the intrinsic oscillatory properties of CA1 hippocampal cholecystokinin-positive interneurons.
In the mammalian hippocampus, the neurotransmitter acetylcholine (ACh) promotes learning and memory storage. During sensory processing and learning, large ACh-dependent electrical oscillatory events are observed, which involve the synchronization of both inhibitory and excitatory neural circuits. While the actions of ACh are known on excitatory hippocampal circuits, its actions on specific inhibitory circuits are poorly understood. We show that two types of cholecystokinin-positive local circuit inhibitory interneuron, the so-called 'basket cells' and 'Schaffer collateral-associated' cells, which innervate separately the cell body and dendritic regions of principal cells, are modulated similarly by cholinergic receptor activation. In both cell types activation of their muscarinic receptors triggers a general increase of excitability and intrinsic oscillatory activity, and a more efficient engagement to slow network oscillations. Knowledge of how cholinergic neuromodulation acts on neurochemically identical but morphologically distinct inhibitory interneurons will allow us to understand the role played by this important neuromodulator during hippocampal-dependent tasks in vivo.
Program in Developmental Neurobiology, Eunice Kennedy Shriver, National Institute of Child Health and Human Development, Bethesda, MA 20892, USA.
Christian A
CA
Cea-del Rio
J Josh
JJ
Lawrence
Ferenc
F
Erdelyi
Gabor
G
Szabo
Chris J
CJ
McBain
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D056547:CA1 Region, Hippocampal / Q000166:cytology / Q000502:physiology*; D002766:Cholecystokinin / Q000235:genetics / Q000378:metabolism*; D002799:Cholinergic Fibers / Q000502:physiology*; D055724:Electrophysiological Phenomena / Q000187:drug effects / Q000502:physiology; D015870:Gene Expression / Q000235:genetics; D005968:Glutamate Decarboxylase / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000235:genetics; D007395:Interneurons / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D009116:Muscarine / Q000494:pharmacology; D043643:Receptor, Muscarinic M1 / Q000235:genetics / Q000378:metabolism; D043587:Receptor, Muscarinic M3 / Q000235:genetics / Q000378:metabolism
D043643:Receptor, Muscarinic M1; D043587:Receptor, Muscarinic M3; D049452:Green Fluorescent Proteins; D009116:Muscarine; D002766:Cholecystokinin; D005968:Glutamate Decarboxylase; C401141:glutamate decarboxylase 2