title: Thalamic synaptic transmission of sensory information modulated by synergistic interaction of adenosine and serotonin.
abstract: The thalamic synapses relay peripheral sensory information to the cortex, and constitute an important part of the thalamocortical network that generates oscillatory activities responsible for different vigilance (sleep and wakefulness) states. However, the modulation of thalamic synaptic transmission by potential sleep regulators, especially by combination of regulators in physiological scenarios, is not fully characterized. We found that somnogen adenosine itself acts similar to wake-promoting serotonin, both decreasing synaptic strength as well as short-term depression, at the retinothalamic synapse. We then combined the two modulators considering the coexistence of them in the hypnagogic (sleep-onset) state. Adenosine plus serotonin results in robust synergistic inhibition of synaptic strength and dramatic transformation of short-term synaptic depression to facilitation. These synaptic effects are not achievable with a single modulator, and are consistent with a high signal-to-noise ratio but a low level of signal transmission through the thalamus appropriate for slow-wave sleep. This study for the first time demonstrates that the sleep-regulatory modulators may work differently when present in combination than present singly in terms of shaping information flow in the thalamocortical network. The major synaptic characters such as the strength and short-term plasticity can be profoundly altered by combination of modulators based on physiological considerations.
authors.affiliation: Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan; Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan.
authors.forename: Ya-Chin
authors.initials: YC
authors.lastname: Yang
authors.forename: Chun-Chang
authors.initials: CC
authors.lastname: Hu
authors.forename: Chen-Syuan
authors.initials: CS
authors.lastname: Huang
authors.forename: Pei-Yu
authors.initials: PY
authors.lastname: Chou
mesh_terms: D000241:Adenosine / Q000494:pharmacology* / Q000502:physiology; D000344:Afferent Pathways / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D000818:Animals; D004357:Drug Synergism; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D005260:Female; D005829:Geniculate Bodies / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology; D018377:Neurotransmitter Agents / Q000494:pharmacology; D009924:Organ Culture Techniques; D043682:Receptor, Adenosine A1 / Q000502:physiology; D012701:Serotonin / Q000494:pharmacology* / Q000502:physiology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D012890:Sleep / Q000187:drug effects / Q000502:physiology; D009435:Synaptic Transmission / Q000187:drug effects* / Q000502:physiology; D013788:Thalamus / Q000166:cytology / Q000187:drug effects* / Q000502:physiology
chemical_list: D018377:Neurotransmitter Agents; D043682:Receptor, Adenosine A1; D017366:Serotonin Receptor Agonists; D012701:Serotonin; D000241:Adenosine
keywords: context-dependent neuromodulation; neuromodulators; short-term synaptic plasticity; sleep-wakefulness regulation; synaptic transmission; thalamocortical network