Dendritic nicotinic receptors modulate backpropagating action potentials and long-term plasticity of interneurons.
Stratum radiatum interneurons, unlike pyramidal cells, are rich in nicotinic acetylcholine receptors (nAChRs); however, the role of these receptors in plasticity has remained elusive. As opposed to previous physiological studies, we found that functional alpha7-subunit-containing nAChRs (alpha7-nAChRs) are abundant on interneuron dendrites of rats. Moreover, dendritic Ca2+ transients induced by activation of alpha7-nAChRs increase as a function of distance from soma. The activation of these extrasynaptic alpha7-nAChRs by cholinergic agonists either facilitated or depressed backpropagating action potentials, depending on the timing of alpha7-nAChR activation. We have previously shown that dendritic alpha7-nAChRs are involved in the regulation of synaptic transmission, suggesting that alpha7-nAChRs may play an important role in the regulation of the spike timing-dependent plasticity. Here we provide evidence that long-term potentiation is indeed boosted by stimulation of dendritic alpha7-nAChRs. Our results suggest a new mechanism for a cholinergic switch in memory encoding and retrieval.
Rózsa
Balázs
B
Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary.
Katona
Gergely
G
Kaszás
Attila
A
Szipöcs
Róbert
R
Vizi
E Sylvester
ES
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D003712:Dendrites / Q000502:physiology*; D007395:Interneurons / Q000166:cytology / Q000502:physiology*; D017774:Long-Term Potentiation / Q000502:physiology*; D008297:Male; D009473:Neuronal Plasticity / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D011978:Receptors, Nicotinic / Q000502:physiology*; D064569:alpha7 Nicotinic Acetylcholine Receptor
C579165:Chrna7 protein, rat; D011978:Receptors, Nicotinic; D064569:alpha7 Nicotinic Acetylcholine Receptor