title: Kidins220/ARMS is a novel modulator of short-term synaptic plasticity in hippocampal GABAergic neurons.
abstract: Kidins220 (Kinase D interacting substrate of 220 kDa)/ARMS (Ankyrin Repeat-rich Membrane Spanning) is a scaffold protein highly expressed in the nervous system. Previous work on neurons with altered Kidins220/ARMS expression suggested that this protein plays multiple roles in synaptic function. In this study, we analyzed the effects of Kidins220/ARMS ablation on basal synaptic transmission and on a variety of short-term plasticity paradigms in both excitatory and inhibitory synapses using a recently described Kidins220 full knockout mouse. Hippocampal neuronal cultures prepared from embryonic Kidins220(-/-) (KO) and wild type (WT) littermates were used for whole-cell patch-clamp recordings of spontaneous and evoked synaptic activity. Whereas glutamatergic AMPA receptor-mediated responses were not significantly affected in KO neurons, specific differences were detected in evoked GABAergic transmission. The recovery from synaptic depression of inhibitory post-synaptic currents in WT cells showed biphasic kinetics, both in response to paired-pulse and long-lasting train stimulation, while in KO cells the respective slow components were strongly reduced. We demonstrate that the slow recovery from synaptic depression in WT cells is caused by a transient reduction of the vesicle release probability, which is absent in KO neurons. These results suggest that Kidins220/ARMS is not essential for basal synaptic transmission and various forms of short-term plasticity, but instead plays a novel role in the mechanisms regulating the recovery of synaptic strength in GABAergic synapses.
authors.affiliation: Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genova, Italy. joachim.scholzstarke@iit.it
authors.forename: Joachim
authors.initials: J
authors.lastname: Scholz-Starke
authors.forename: Fabrizia
authors.initials: F
authors.lastname: Cesca
authors.forename: Giampietro
authors.initials: G
authors.lastname: Schiavo
authors.forename: Fabio
authors.initials: F
authors.lastname: Benfenati
authors.forename: Pietro
authors.initials: P
authors.lastname: Baldelli
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D059330:GABAergic Neurons / Q000378:metabolism*; D006624:Hippocampus / Q000378:metabolism; D008565:Membrane Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D009473:Neuronal Plasticity / Q000502:physiology*; D018408:Patch-Clamp Techniques; D009435:Synaptic Transmission / Q000502:physiology*
chemical_list: C544017:Kidins220 protein, mouse; D008565:Membrane Proteins