Related Experiment Video
Updated: Feb 25, 2026
07:13
3D Modeling of Dendritic Spines with Synaptic Plasticity
Published on: May 18, 2020
7.4K
Attenuation of Synaptic Potentials in Dendritic Spines.
Taekyung Kwon1, Masayuki Sakamoto1, Darcy S Peterka1
1Neurotechnology Center, Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
Cell Reports
|August 3, 2017
Summary
Dendritic spines attenuate excitatory inputs, acting as electrical compartments that reduce synaptic signals reaching the parent neuron. Back-propagating action potentials, however, are unaffected, impacting neuronal integration and plasticity.
Area of Science:
- Neuroscience
- Cellular Electrophysiology
Background:
- Dendritic spines are primary sites of excitatory input in mammalian neurons.
- The biophysical properties and functional role of dendritic spines in neuronal integration remain incompletely understood.
Purpose of the Study:
- To investigate the electrical properties of dendritic spines.
- To determine how spines influence the propagation and integration of synaptic inputs and action potentials.
Main Methods:
- Utilized an advanced genetically encoded voltage indicator (ArcLight) in cultured hippocampal neurons.
- Employed two-photon glutamate uncaging to evoke excitatory postsynaptic potentials (uEPSPs).
- Measured voltage changes during back-propagating action potentials (bAPs) and uEPSPs.
Main Results:
- Back-propagating action potentials (bAPs) were found to fully invade dendritic spines without attenuation.
- Evoked excitatory postsynaptic potentials (uEPSPs) were significantly attenuated (up to 4-fold) upon propagation from spines to parent dendrites.
- Simultaneous occurrence of bAPs and uEPSPs led to sublinear summation of membrane potential.
Conclusions:
- Dendritic spines function as electrical compartments, modulating the impact of synaptic inputs on the neuron.
- Spine-induced attenuation of EPSPs suggests a mechanism for regulating synaptic efficacy and neuronal excitability.
- These findings have significant implications for understanding synaptic plasticity and dendritic integration processes.
Related Concept Videos
01:28Integration of Synaptic Events
4.7K
Synaptic integration mainly includes the summation of graded potentials. Graded potentials, regardless of their type, cause subtle alterations in membrane voltage, resulting in either depolarization or hyperpolarization. These incremental changes, when combined or summed, can propel the neuron toward its threshold. Consider, for example, a membrane experiencing a +15 mV shift, causing it to depolarize from -70 mV to -55 mV. In this scenario, graded potentials govern the membrane's ability to...
4.7K
01:29Excitatory and Inhibitory Effects of Neurotransmitters
13.7K
When an action potential reaches the presynaptic axon terminal, it releases neurotransmitters from the neuron into the synaptic cleft at a chemical synapse. The released neurotransmitter can be excitatory or inhibitory. The critical criteria commonly used to determine whether a molecule is a neurotransmitter at a chemical synapse are the molecule's presence in the presynaptic neuron. Second, its release is in response to strong presynaptic depolarization. And lastly, the presence of...
13.7K
01:32Postsynaptic Potential (PSP)
6.1K
Postsynaptic potential (PSP) refers to a change in the electrical potential of a neuron when neurotransmitters released by presynaptic neurons bind to postsynaptic receptors. This potential can either be excitatory, leading to depolarization and ultimately action potential generation, or inhibitory, leading to hyperpolarization and suppression of the postsynaptic neuron.
There are two types of receptors: ionotropic and metabotropic.
The ionotropic receptor is the membrane protein that has an...
There are two types of receptors: ionotropic and metabotropic.
The ionotropic receptor is the membrane protein that has an...
6.1K
01:25Long-term Potentiation
3.7K
Long-term potentiation, or LTP, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in the brain. LTP is the process of synaptic strengthening that occurs over time between pre and postsynaptic neuronal connections. The synaptic strengthening of LTP works in opposition to the synaptic weakening of long-term depression (LTD) and together are the main mechanisms that underlie learning and memory.
Hebbian LTP
LTP can occur when...
Hebbian LTP
LTP can occur when...
3.7K
01:35Long-term Potentiation
58.9K
Long-term potentiation, or LTP, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in the brain. LTP is the process of synaptic strengthening that occurs over time between pre- and postsynaptic neuronal connections. The synaptic strengthening of LTP works in opposition to the synaptic weakening of long-term depression (LTD) and together are the main mechanisms that underlie learning and memory.
58.9K
01:26Chemical Synapses
4.9K
Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell.
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
4.9K