Related Experiment Video
Updated: Jun 11, 2026
11:02
Presynaptically Silent Synapses Studied with Light Microscopy
Published on: January 4, 2010
Synapse-specific metaplasticity: to be silenced is not to silence 2B
Benjamin D Philpot1, R Suzanne Zukin
1Department of Cell and Molecular Physiology, Curriculum in Neurobiology, and UNC Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, USA.
Neuron
|July 13, 2010
Summary
Inactive synapses are not eliminated but are primed for potentiation and circuit integration. This priming involves an increase in NR2B-containing NMDA receptors, preparing them for future activity.
Area of Science:
- Neuroscience
- Synaptic Plasticity
- Neural Circuitry
Background:
- Investigates the fate of quiescent (inactive) synapses within a network of active synapses.
- Examines the mechanisms governing synapse maintenance and potential incorporation into functional circuits.
Discussion:
- Inactive synapses are not inherently destined for elimination.
- These synapses undergo molecular changes that prime them for future activation and integration.
- Upregulation of specific NMDA receptor subunits (NR2B) is a key mechanism.
Key Insights:
- Quiescent synapses are actively maintained and prepared for plasticity.
- NR2B-containing NMDA receptors play a crucial role in priming inactive synapses.
- This process facilitates the dynamic remodeling of neural circuits.
Outlook:
- Understanding synapse priming could reveal new therapeutic targets for neurological disorders.
- Further research may elucidate the precise signaling pathways involved in this priming process.
- This finding contributes to a broader understanding of neural circuit development and adaptation.
Related Concept Videos
01:26Chemical Synapses
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...
01:26Chemical Synapses
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...
01:32Chromatin Modification in iPS Cells
Chromatin modification alters gene expression; therefore, scientists can add histone-modifying enzymes, histone variants, and chromatin remodeling complexes to somatic cells to aid reprogramming into pluripotent stem (iPS) cells.
Compact chromatin makes reprogramming difficult. Enzymes, such as histone demethylases and acetyltransferases, are often added during reprogramming to loosen the chromatin, making the DNA more accessible to transcription factors. Molecules that inhibit histone...
Compact chromatin makes reprogramming difficult. Enzymes, such as histone demethylases and acetyltransferases, are often added during reprogramming to loosen the chromatin, making the DNA more accessible to transcription factors. Molecules that inhibit histone...
01:58X-Inactivation
The human X chromosome contains over ten times the number of genes as in the Y chromosome. Since males have only one X chromosome, and females have two, one might expect females to produce twice as many of the proteins, with undesirable results.
02:30Genomic Imprinting and Inheritance
Diploid organisms inherit genetic material through chromosomes from both parents. Copies of the same gene are known as alleles. In most cases, both alleles are simultaneously expressed and allow various cellular processes to function optimally. If one of the alleles is missing or mutated, the expression of the other allele can compensate; however, this is not true for all genes.
The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as...
The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as...
02:32Position-effect Variegation
In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.