title: Presynaptic GABAB Receptors Regulate Hippocampal Synapses during Associative Learning in Behaving Mice.
abstract: GABAB receptors are the G-protein-coupled receptors for GABA, the main inhibitory neurotransmitter in the central nervous system. Pharmacological activation of GABAB receptors regulates neurotransmission and neuronal excitability at pre- and postsynaptic sites. Electrophysiological activation of GABAB receptors in brain slices generally requires strong stimulus intensities. This raises the question as to whether behavioral stimuli are strong enough to activate GABAB receptors. Here we show that GABAB1a-/- mice, which constitutively lack presynaptic GABAB receptors at glutamatergic synapses, are impaired in their ability to acquire an operant learning task. In vivo recordings during the operant conditioning reveal a deficit in learning-dependent increases in synaptic strength at CA3-CA1 synapses. Moreover, GABAB1a-/- mice fail to synchronize neuronal activity in the CA1 area during the acquisition process. Our results support that activation of presynaptic hippocampal GABAB receptors is important for acquisition of a learning task and for learning-associated synaptic changes and network dynamics.
authors: Division of Neurosciences, Pablo de Olavide University, 41013, Seville, Spain.
authors: M Teresa
authors: MT
authors: Jurado-Parras
authors: Division of Neurosciences, Pablo de Olavide University, 41013, Seville, Spain.
authors: José M
authors: JM
authors: Delgado-García
authors: Division of Neurosciences, Pablo de Olavide University, 41013, Seville, Spain.
authors: Raudel
authors: R
authors: Sánchez-Campusano
authors: Department of Biomedicine, University of Basel, 4056, Basel, Switzerland.
authors: Martin
authors: M
authors: Gassmann
authors: Department of Biomedicine, University of Basel, 4056, Basel, Switzerland.
authors: Bernhard
authors: B
authors: Bettler
authors: Division of Neurosciences, Pablo de Olavide University, 41013, Seville, Spain.
authors: Agnès
authors: A
authors: Gruart
mesh_terms: D000818:Animals; D001245:Association Learning / Q000502:physiology*; D056547:CA1 Region, Hippocampal / Q000378:metabolism; D056654:CA3 Region, Hippocampal / Q000378:metabolism; D003216:Conditioning, Operant; D006624:Hippocampus / Q000378:metabolism*; D017774:Long-Term Potentiation; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D023421:Models, Animal; D009473:Neuronal Plasticity; D017966:Pyramidal Cells / Q000502:physiology; D018080:Receptors, GABA-B / Q000378:metabolism*; D017661:Receptors, Presynaptic / Q000378:metabolism*; D013569:Synapses / Q000378:metabolism*; D055366:Synaptic Potentials
chemical_list: D018080:Receptors, GABA-B; D017661:Receptors, Presynaptic