Mapping calcium transients in the dendrites of Purkinje cells from the guinea‐pig cerebellum in vitro.

Ross, W. N.; Werman, R.

doi:10.1113/jphysiol.1987.sp016659

Cited by 215 publications

(107 citation statements)

References 28 publications

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“…Llinas and Sugimori (3) have given convincing evidence for Ca channels in Purkinje dendrites, which under some circumstances can generate Ca action potentials. Ca imaging experiments are also consistent with the presence of dendritic Ca channels (7,8). Our records clearly show active responses in the dendrites but mediated by Na ions.…”

Section: Discussionsupporting

confidence: 86%

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Sodium action potentials in the dendrites of cerebellar Purkinje cells.

Regehr

Konnerth

Armstrong

1992

Proc. Natl. Acad. Sci. U.S.A.

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We report here that in cerebellar Purkinje cells from which the axon has been removed, positive voltage steps applied to the voltage-clamped soma produce spikes of active current. The spikes are inward, are all-or-none, have a duration of -1 ms, and are reversibly eliminated by tetrodotoxin, a Na channel poison. From cell to cell, the amplitude of the spikes ranges from 4 to 20 nA. Spike latency decreases as the depolarizing step is made larger. These spikes clearly arise at a site where the voltage is not controlled, remote from the soma. From these facts we conclude that Purk' je cell dendrites contain a sufficient density of Na channels to generate action potentials. Activation by either parallel fiber or climbing fiber synapses produces similar spikes, suggesting that normal input elicits Na action potentials in the dendrites. These findings greatly alter current views of how dendrites in these cells respond to synaptic input. (2)(3)(4)(5). In experiments on isolated neocortical pyramidal cells from newborn rats, differential microperfusion was used to show the presence of Na channels in dendritic stumps that stretched as far as 100 ,um from the soma (6).For neurons in situ, the distribution of spike-generating ion channels has been inferred primarily from intradendritic recordings (3-5). Such measurements suggested that Purkinje cell dendrites could generate Ca action potentials but were devoid of Na channels (2, 3). Dendrites of hippocampal pyramidal cells have action potentials produced by both Na channels and Ca channels (4, 5). More recently, microfluorometric imaging techniques have also provided some evidence regarding channel distribution (7-9).The recent application of whole-cell patch-clamp techniques to brain slices holds promise for helping with these questions. Here we have used the voltage clamp in an unconventional way to show the presence of Na spikes in the dendrites of cerebellar Purkinje cells. MATERIALS AND METHODSExperiments were done on 200-,m sagittal slices of cerebellar vermis from 22-to 55-day rats, by using methods similar to those described (10, 11). In brief, the cerebellum was quickly removed from the animal and placed in ice-cold saline for 1-2 min. A Vibratome was used to cut slices, which were then allowed to incubate for 1-5 hr at 350C. A slice was placed in a simple chamber on a Zeiss Axioskop and viewed with a 40x water immersion objective. We elected to view the preparation with bright-field rather than Nomarski optics; it was possible to resolve individual Purkinje cells, their dendrites, and, in many cases, the axon. Cells near the surface of the slice were selected for recording and were gently cleaned as described by Edwards et al. (10).In cases where axotomy was done, a well-defined procedure was adopted to ensure removal of the axon. Two investigators carefully inspected the cells at various stages throughout the procedure to minimize the possibility oferror. We selected a Purkinje cell with a clearly visible axon. Pressure was applied to the cleaning pipet...

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Section: Discussionsupporting

confidence: 86%

“…Dendrites of hippocampal pyramidal cells have action potentials produced by both Na channels and Ca channels (4,5). More recently, microfluorometric imaging techniques have also provided some evidence regarding channel distribution (7)(8)(9).…”

mentioning

confidence: 99%

Sodium action potentials in the dendrites of cerebellar Purkinje cells.

Regehr

Konnerth

Armstrong

1992

Proc. Natl. Acad. Sci. U.S.A.

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“…Secondly, early trials suggest that the filling of neurones with calcium sensitive dyes (Fura-2) could be combined with the techniques described above. This could allow the measurement of synaptically activated Ca 2 + signals in single neurones and their processes (Ross and Werman 1987) together with measurements of ionic conductance changes.…”

Section: Discussionmentioning

confidence: 99%

A thin slice preparation for patch clamp recordings from neurones of the mammalian central nervous system

et al. 1989

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Abstract.(1) A preparation is described which allows patch clamp recordings to be made on mammalian central nervous system (CNS) neurones in situ. (2) A vibrating tissue slicer was used to cut thin slices in which individual neurones could be identified visually. Localized cleaning of cell somata with physiological saline freed the cell membrane, allowing the formation of a high resistance seal between the membrane and the patch pipette. (3) The various configurations of the patch clamp technique were used to demonstrate recording of membrane potential, whole cell currents and single channel currents from neurones and isolated patches. (4) The patch clamp technique was used to record from neurones filled with fluorescent dyes. Staining was achieved by filling cells during recording or by previous retrograde labelling. (5) Thin slice cleaning and patch clamp techniques were shown to be applicable to the spinal cord and almost any brain region and to various species. These techniques are also applicable to animals of a wide variety of postnatal ages, from newborn to adult.

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“…Accordingly, CF activation produces a strong postsynaptic depolarization that is mediated by ␣-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors and evokes an all-or-none spike with multiple peaks. These ''complex spikes'' are accompanied by a large Ca 2ϩ transient covering broad regions of the PC dendritic tree (7)(8)(9)(10). Complex spikes, as recorded at the soma, are characterized by an initial, fast spike component followed by a series of smaller spikelets riding on top of a plateau.…”

mentioning

confidence: 99%

Long-term depression of climbing fiber-evoked calcium transients in Purkinje cell dendrites

Weber

Zeeuw

Linden

et al. 2003

Proc. Natl. Acad. Sci. U.S.A.

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In recent years much has been learned about the molecular requirements for inducing long-term synaptic depression (LTD) in various brain regions. However, very little is known about the consequences of LTD induction for subsequent signaling events in postsynaptic neurons. We have addressed this issue by examining homosynaptic LTD at the cerebellar climbing fiber (CF)-Purkinje cell (PC) synapse. This synapse is built for reliable and massive excitation: Activation of a single axon produces an unusually large ␣-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor-mediated synaptic current, the depolarization of which drives a regenerative complex spike producing a large, widespread Ca 2؉ transient in PC dendrites. Here we test whether CF LTD has an impact on dendritic, complex spikeevoked Ca 2؉ signals by simultaneously performing long-term recordings of complex spikes and microfluorimetric Ca 2؉ measurements in PC dendrites in rat cerebellar slices. Our data show that LTD of the CF excitatory postsynaptic current produces a reduction in both slow components of the complex spike waveform and complex spikeevoked dendritic Ca 2؉ transients. This LTD of dendritic Ca 2؉ signals may provide a neuroprotective mechanism and͞or constitute ''heterosynaptic metaplasticity'' by reducing the probability for subsequent induction of those forms of use-dependent plasticity, which require CF-evoked Ca 2؉ signals such as parallel fiber-PC LTD and interneuron-PC LTP.I n the adult mammalian brain, Purkinje cells (PCs) receive two types of excitatory synaptic input: (i) from numerous parallel fibers (PFs), which are the axons of granule cells, and (ii) from a single climbing fiber (CF), which originates from the inferior olive. The PFs primarily form synaptic contacts at the distal compartments of the PC dendrite as well as at spiny branchlets of more proximal compartments, whereas the CF predominately contacts the proximal compartment at the primary dendrite via spines found in this region at low density (1-3). The CF input is extremely powerful, consisting of Ϸ1,400 release sites (4) that are characterized by a high release probability (5, 6). Accordingly, CF activation produces a strong postsynaptic depolarization that is mediated by ␣-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors and evokes an all-or-none spike with multiple peaks. These ''complex spikes'' are accompanied by a large Ca 2ϩ transient covering broad regions of the PC dendritic tree (7-10). Complex spikes, as recorded at the soma, are characterized by an initial, fast spike component followed by a series of smaller spikelets riding on top of a plateau. It has been suggested that the fast component is a somatically generated Na ϩ spike, whereas the following slower components are produced mainly by dendritic Ca 2ϩ conductances (11, 12). More recently it has been shown that isolated PC somata can fire repetitive spike patterns on their own that are mediated by a ''resurgent'' Na ϩ current (13). Thus, it is likely that both Ca 2ϩ and Na ϩ ...

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Mapping calcium transients in the dendrites of Purkinje cells from the guinea‐pig cerebellum in vitro.

Cited by 215 publications

References 28 publications

Sodium action potentials in the dendrites of cerebellar Purkinje cells.

Sodium action potentials in the dendrites of cerebellar Purkinje cells.

A thin slice preparation for patch clamp recordings from neurones of the mammalian central nervous system

Long-term depression of climbing fiber-evoked calcium transients in Purkinje cell dendrites

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