Synaptic dynamics and long-term plasticity at synapses of Purkinje cells onto neighboring Purkinje cells of a mormyrid fish: a dual cell recording study.
The input synapses of cerebellar Purkinje cells (PCs) have been extensively studied and much has been learned about their dynamics, plasticity and functionality. In contrast there is limited information available about PC output synapses. This study uses dual cell recording methods to investigate synaptic dynamics and plasticity at individual PC synapses onto neighboring PCs in in vitro preparations of the mormyrid cerebellum. This synaptic connectivity may be strong or weak. For strong connections, inhibitory postsynaptic potentials (IPSPs) or currents (IPSCs) are synchronized with the action potentials of the presynaptic cell. For weak connections, however, the pre- and postsynaptic potentials are no longer synchronized, and presynaptic burst firing at intraburst rates of ∼50 Hz or higher is required to reliably induce the postsynaptic inhibition. A depression of this postsynaptic inhibition was observed for both types of connectivity following repeated presynaptic bursts, which was subsequently largely reversed following pairings of the presynaptic burst-induced IPSPs/IPSCs with evoked burst firing of the postsynaptic cell. Moreover, the original postsynaptic depression was found to be either augmented or reversed depending on the temporal order of each pair of additional pre- and postsynaptic cell activations, hence demonstrating a reversible and spike timing-dependent plasticity (STDP) at this synapse.
Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA 98101, USA. ypzhang@fmmu.edu.cn
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Zhang
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Magnus
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Han
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D055592:Biophysical Phenomena / Q000187:drug effects / Q000502:physiology; D001703:Biophysics; D002531:Cerebellum / Q000166:cytology; D004305:Dose-Response Relationship, Drug; D004555:Electric Fish; D004558:Electric Stimulation; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D058787:GABA-A Receptor Antagonists / Q000494:pharmacology; D066298:In Vitro Techniques; D053444:Inhibitory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology*; D008239:Lysine / Q000031:analogs & derivatives / Q000378:metabolism; D009415:Nerve Net / Q000166:cytology / Q000502:physiology*; D009434:Neural Pathways / Q000187:drug effects / Q000502:physiology; D018408:Patch-Clamp Techniques; D011689:Purkinje Cells / Q000166:cytology / Q000502:physiology*; D013569:Synapses / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors
D018691:Excitatory Amino Acid Antagonists; D058787:GABA-A Receptor Antagonists; C013411:biocytin; D008239:Lysine; D001640:Bicuculline