Fast synaptic subcortical control of hippocampal circuits.
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.
Varga
Viktor
V
Institute of Experimental Medicine, Budapest 1083, Hungary. vargav@koki.hu
Losonczy
Attila
A
Zemelman
Boris V
BV
Borhegyi
Zsolt
Z
Nyiri
Gábor
G
Domonkos
Andor
A
Hangya
Balázs
B
Holderith
Noémi
N
Magee
Jeffrey C
JC
Freund
Tamás F
TF
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*
D012701:Serotonin; D018698:Glutamic Acid