title: Adenosine Differentially Modulates Synaptic Transmission of Excitatory and Inhibitory Microcircuits in Layer 4 of Rat Barrel Cortex.
abstract: Adenosine is considered to be a key regulator of sleep homeostasis by promoting slow-wave sleep through inhibition of the brain's arousal centers. However, little is known about the effect of adenosine on neuronal network activity at the cellular level in the neocortex. Here, we show that adenosine differentially modulates synaptic transmission between different types of neurons in cortical layer 4 (L4) through activation of pre- and/or postsynaptically located adenosine A1 receptors. In recurrent excitatory connections between L4 spiny neurons, adenosine suppresses synaptic transmission through activation of both pre- and postsynaptic A1 receptors. In reciprocal excitatory and inhibitory connections between L4 spiny neurons and interneurons, adenosine strongly suppresses excitatory transmission via activating presynaptic A1 receptors but only slightly suppresses inhibitory transmission via activating postsynaptic A1 receptors. Adenosine has no effect on inhibitory transmission between L4 interneurons. The effect of adenosine is concentration dependent and first visible at a concentration of 1 μM. The effect of adenosine is blocked by the specific A1 receptor antagonist, 8-cyclopentyltheophylline or the nonspecific adenosine receptor antagonist, caffeine. By differentially affecting excitatory and inhibitory synaptic transmission, adenosine changes the excitation-inhibition balance and causes an overall shift to lower excitability in L4 primary somatosensory (barrel) cortical microcircuits.
authors: Institute of Neuroscience and Medicine, INM-2, Research Centre Jülich, D-52425 Jülich, Germany.
authors: Guanxiao
authors: G
authors: Qi
authors: Institute of Neuroscience and Medicine, INM-2, Research Centre Jülich, D-52425 Jülich, Germany.|Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3508 AB Utrecht, The Netherlands.
authors: Karlijn
authors: K
authors: van Aerde
authors: Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors: Ted
authors: T
authors: Abel
authors: Institute of Neuroscience and Medicine, INM-2, Research Centre Jülich, D-52425 Jülich, Germany.|Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, D-52074 Aachen, Germany.|Jülich-Aachen Research Alliance-Brain, Translational Brain Medicine, D-52074 Aachen, Germany.
authors: Dirk
authors: D
authors: Feldmeyer
mesh_terms: D000241:Adenosine / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D007395:Interneurons / Q000187:drug effects; D017966:Pyramidal Cells / Q000187:drug effects / Q000502:physiology; D017208:Rats, Wistar; D043682:Receptor, Adenosine A1 / Q000187:drug effects; D012890:Sleep / Q000187:drug effects; D013003:Somatosensory Cortex / Q000187:drug effects*; D013569:Synapses / Q000187:drug effects*; D009435:Synaptic Transmission / Q000187:drug effects* / Q000502:physiology
chemical_list: D043682:Receptor, Adenosine A1; D000241:Adenosine
keywords: A1 receptors; adenosine; barrel cortex; layer 4; synaptic transmission