The morphoelectrotonic transform: a graphical approach to dendritic function

Zador, A. M.; Agmon-Snir, Hagai; Segev, Idan

doi:10.1523/jneurosci.15-03-01669.1995

Cited by 126 publications

(118 citation statements)

References 40 publications

Supporting

Mentioning

116

Contrasting

Order By: Relevance

“…To compare the attenuation of the EPSP obtained in our measurements with the results reported for other cell types, we approximated the decay of the peak EPSP amplitude with distance by a single exponential and used this relationship to extract the length of the primary dendrite over which a typical threshold EPSP attenuates to 1/e of its initial amplitude in the tuft. This distance, sometimes called the mean apparent "length constant" (Berger et al, 2001) or mean 1/e attenuation (Larkum et al, 1998), is a useful functional measure of the efficacy of signal transfer between two points on a particular dendrite, although the length constant of a cable is strictly defined only for the infinite cylinder of the uniform diameter (Rall, 1977;Zador et al, 1995). The mean apparent length constant in the primary dendrites of mitral cells was unusually long, corresponding to 1246 Ϯ 217 m (n ϭ 10) for control and 1007 Ϯ 256 m (n ϭ 4) for experiments in the presence of QX-314.…”

Section: Epsp Characteristics In the Glomerular Tuft And Trunk Of Thementioning

confidence: 99%

Voltage Imaging from Dendrites of Mitral Cells: EPSP Attenuation and Spike Trigger Zones

Djurišić¹,

Antic²,

Chen³

et al. 2004

J. Neurosci.

118

130

View full text Add to dashboard Cite

To obtain a more complete description of individual neurons, it is necessary to complement the electrical patch pipette measurements with technologies that permit a massive parallel recording from many sites on neuronal processes. This can be achieved by using voltage imaging with intracellular dyes. With this approach, we investigated the functional structure of a mitral cell, the principal output neuron in the rat olfactory bulb. The most significant finding concerns the characteristics of EPSPs at the synaptic sites and surprisingly small attenuation along the trunk of the primary dendrite. Also, the experiments were performed to determine the number, location, and stability of spike trigger zones, the excitability of terminal dendritic branches, and the pattern and nature of spike initiation and propagation in the primary and secondary dendrites. The results show that optical data can be used to deduce the amplitude and shape of the EPSPs evoked by olfactory nerve stimulation at the site of origin (glomerular tuft) and to determine its attenuation along the entire length of the primary dendrite. This attenuation corresponds to an unusually large mean apparent "length constant" of the primary dendrite. Furthermore, the images of spike trigger zones showed that an action potential can be initiated in three different compartments of the mitral cell: the soma-axon region, the primary dendrite trunk, and the terminal dendritic tuft, which appears to be fully excitable. Finally, secondary dendrites clearly support the active propagation of action potentials.

show abstract

Section: Epsp Characteristics In the Glomerular Tuft And Trunk Of Thementioning

confidence: 99%

Voltage Imaging from Dendrites of Mitral Cells: EPSP Attenuation and Spike Trigger Zones

Djurišić¹,

Antic²,

Chen³

et al. 2004

J. Neurosci.

118

130

View full text Add to dashboard Cite

show abstract

“…From cable and two-port theory the conclusion can be drawn, however, that the degree to which neuronal morphology is distorted by the MET is determined by a complicated interplay of segment diameter and boundary effects (see [12,23]). Predictions based solely on morphological measurements of how the METs of wildtype and transgenic neocortical pyramidal neurons may differ are therefore not possible.…”

Section: Discussionmentioning

confidence: 99%

“…As we see from (6), L ij preserves this property of e-fold decay for networks of finite cables such as dendritic trees. This is not true for the classical measure X (see [12,23]). If stimulus and recording location are interchanged, the electrotonic distance is L ji = lnA ji .…”

Section: Compartmental Modeling and Morphoelectrotonic Transformmentioning

confidence: 99%

“…The MET maps the neuron from anatomical space into electrotonic space, using the logarithm of voltage attenuation as the distance metric. This transformation was described by several authors [12,23]. In the following, the approach of these authors is outlined.…”

Section: Compartmental Modeling and Morphoelectrotonic Transformmentioning

confidence: 99%

“…In particular, we used the morphoelectrotonic transform (MET, cf. [12,23]) to explore the scaling mode realized by the larger dendritic trees of synRas pyramidal cells.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Scaling properties of pyramidal neurons in mice neocortex

Schierwagen

Alpár

Gärtner

2007

Mathematical Biosciences

View full text Add to dashboard Cite

Dendritic morphology is the structural correlate for receiving and processing inputs to a neuron. An interesting question then is what the design principles and the functional consequences of enlarged or shrinked dendritic trees might be. As yet, only a few studies have examined the effects of neuron size changes. Two theoretical scaling modes have been analyzed, conservative (isoelectrotonic) scaling (preserves the passive and active response properties) and isometric scaling (steps up low pass-filtering of inputs). It has been suggested that both scaling modes were verified in neuroanatomical studies. To overcome obvious limitations of these studies like small size of analyzed samples and restricted validity of utilized scaling measures, we considered the scaling problem of neurons on the basis of large sample data and by employing a more general method of scaling analysis. This method consists in computing the morphoelectrotonic transform (MET) of neurons. The MET maps the neuron from anatomical space into electrotonic space using the logarithm of voltage attenuation as the distance metric. The theory underlying this approach is described and then applied to two samples of morphologically reconstructed pyramidal neurons (cells from neocortex of wildtype and synRas transgenic mice) using the NEURON simulator. In a previous study, we could verify a striking increase of dendritic tree size in synRas pyramidal neurons. Surprisingly, in this study the statistical analysis of the sample MET dendrograms revealed that the electrotonic architecture of these neurons scaled roughly in a MET-conserving mode. In conclusion, our results suggest only a minor impact of the Ras protein on dendritic electroanatomy, with non-significant changes of most regions of the corresponding METs.

show abstract

Dendrites of classes of hippocampal neurons differ in structural complexity and branching patterns

1999

View full text Add to dashboard Cite

Dendrites of reconstructed hippocampal neurons were analyzed for morphometric, topologic, and fractal parameters (n ϭ 32 quantities) to investigate neuronal groupings and growth characteristics with a common set of assumptions. The structures studied included CA1 and CA3 pyramidal cells, interneurons, and granule cells from young animals (71 cells in total). Most of the cells showed no characteristic fractal dimension; rather, the scaling relation could be well represented by a two-parameter fit, of which one parameter showed a significant difference between cell classes. Other significant quantities that differentiated cell classes were related to the complexity of the dendritic tree (number of branch points and maximal terminal branch order) and the cell's electrical properties such as the mean attenuation between the soma and terminals. Principal components analysis produced combined measures of only slightly greater discriminative power than the best individual measures, indicating that the elementary quantities capture most of the structural variation between hippocampal cell groups. Another finding was that for all cells the mean segment length increased with dendritic branch order, which is consistent with decreasing branching probability as a function of the path distance from the soma. Analysis of another set of CA1 pyramidal neurons from aged animals (n ϭ 15; 22-24 months) showed only a few significant differences than those from young animals (n ϭ 11; a subset of n ϭ 71) of which the most important was a straightening of the paths between terminals and the soma. The quantities analyzed in these reconstructed hippocampal neurons may reflect both intrinsic neuronal characteristics and extrinsic influences. Hippocampal cell groupings (i.e., pyramidal cells as opposed to dentate granule cells and interneurons) were significantly differentiated by most parameters. These differences and parameter values may be critical for understanding and generating synthetic neuronal populations for modelling studies.

show abstract

The morphoelectrotonic transform: a graphical approach to dendritic function

Cited by 126 publications

References 40 publications

Voltage Imaging from Dendrites of Mitral Cells: EPSP Attenuation and Spike Trigger Zones

Voltage Imaging from Dendrites of Mitral Cells: EPSP Attenuation and Spike Trigger Zones

Scaling properties of pyramidal neurons in mice neocortex

Dendrites of classes of hippocampal neurons differ in structural complexity and branching patterns

Contact Info

Product

Resources

About