title: Fast synaptic subcortical control of hippocampal circuits.
abstract: Cortical information processing is under state-dependent control of subcortical neuromodulatory systems. Although this modulatory effect is thought to be mediated mainly by slow nonsynaptic metabotropic receptors, other mechanisms, such as direct synaptic transmission, are possible. Yet, it is currently unknown if any such form of subcortical control exists. Here, we present direct evidence of a strong, spatiotemporally precise excitatory input from an ascending neuromodulatory center. Selective stimulation of serotonergic median raphe neurons produced a rapid activation of hippocampal interneurons. At the network level, this subcortical drive was manifested as a pattern of effective disynaptic GABAergic inhibition that spread throughout the circuit. This form of subcortical network regulation should be incorporated into current concepts of normal and pathological cortical function.
authors.affiliation: Institute of Experimental Medicine, Budapest 1083, Hungary. vargav@koki.hu
authors.forename: Viktor
authors.initials: V
authors.lastname: Varga
authors.forename: Attila
authors.initials: A
authors.lastname: Losonczy
authors.forename: Boris V
authors.initials: BV
authors.lastname: Zemelman
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Borhegyi
authors.forename: Gábor
authors.initials: G
authors.lastname: Nyiri
authors.forename: Andor
authors.initials: A
authors.lastname: Domonkos
authors.forename: Balázs
authors.initials: B
authors.lastname: Hangya
authors.forename: Noémi
authors.initials: N
authors.lastname: Holderith
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Magee
authors.forename: Tamás F
authors.initials: TF
authors.lastname: Freund
mesh_terms: D000818:Animals; D004558:Electric Stimulation; D019706:Excitatory Postsynaptic Potentials; D018698:Glutamic Acid / Q000502:physiology; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D053444:Inhibitory Postsynaptic Potentials; D007395:Interneurons / Q000502:physiology*; D051379:Mice; D009433:Neural Inhibition / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology; D009475:Neurons, Afferent / Q000502:physiology*; D018408:Patch-Clamp Techniques; D010775:Photic Stimulation; D011903:Raphe Nuclei / Q000166:cytology / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000502:physiology*; D013569:Synapses / Q000502:physiology*; D055366:Synaptic Potentials / Q000502:physiology*
chemical_list: D012701:Serotonin; D018698:Glutamic Acid