Glutamate release during LTD at cerebellar climbing fiber–Purkinje cell synapses

It is widely thought that persistent, use-dependent alterations in synaptic strength such as long-term synaptic potentiation (LTP) and depression (LTD) underlie at least a portion of memory traces in the brain, but the exact cellular locus of expression for these alterations remains to be determined. They could be expressed presynaptically as a decrease in transmitter release, postsynaptically as a decrease in the synaptic current evoked by a fixed delivery of transmitter, as an increase in the number of functional synaptic contacts, or by a combination of these mechanisms. Here we report that LTD at the climbing fiber–Purkinje cell synapse in rat cerebellum was not associated with changes in a synaptic cleft glutamate transient, indicating that this type of LTD is most likely expressed postsynaptically.

[1]  D. Linden,et al.  Expression of Cerebellar Long-Term Depression Requires Postsynaptic Clathrin-Mediated Endocytosis , 2000, Neuron.

[2]  C. Jahr,et al.  Multivesicular Release at Climbing Fiber-Purkinje Cell Synapses , 2001, Neuron.

[3]  W G Regehr,et al.  Calcium Dependence and Recovery Kinetics of Presynaptic Depression at the Climbing Fiber to Purkinje Cell Synapse , 1998, The Journal of Neuroscience.

[4]  Masanobu Kano,et al.  Presynaptic origin of paired‐pulse depression at climbing fibre‐Purkinje cell synapses in the rat cerebellum , 1998, The Journal of physiology.

[5]  R. Huganir,et al.  Cerebellar Long-Term Depression Requires PKC-Regulated Interactions between GluR2/3 and PDZ Domain–Containing Proteins , 2000, Neuron.

[6]  R. Silver,et al.  Locus of frequency‐dependent depression identified with multiple‐probability fluctuation analysis at rat climbing fibre‐Purkinje cell synapses , 1998, The Journal of physiology.

[7]  E. D’Angelo,et al.  Beyond parallel fiber LTD: the diversity of synaptic and non-synaptic plasticity in the cerebellum , 2001, Nature Neuroscience.

[8]  P. Strata,et al.  Plasticity of the olivocerebellar pathway , 1998, Trends in Neurosciences.

[9]  R. Tsien,et al.  Variability of Neurotransmitter Concentration and Nonsaturation of Postsynaptic AMPA Receptors at Synapses in Hippocampal Cultures and Slices , 1999, Neuron.

[10]  D. Linden,et al.  Long-Term Depression of the Cerebellar Climbing Fiber–Purkinje Neuron Synapse , 2000, Neuron.

[11]  D. Linden.  The expression of cerebellar LTD in culture is not associated with changes in AMPA-receptor kinetics, agonist affinity, or unitary conductance , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[12]  S. Mikawa,et al.  Disruption of AMPA receptor GluR2 clusters following long‐term depression induction in cerebellar Purkinje neurons , 2000, The EMBO journal.