Related Experiment Video
Updated: Feb 7, 2026
12:22
Automated Quantification of Synaptic Fluorescence in C. elegans
Published on: August 10, 2012
10.8K
Rap2 and TNIK control Plexin-dependent tiled synaptic innervation in C. elegans
Xi Chen1, Akihiro Ce Shibata2, Ardalan Hendi1
1Department of Zoology, The University of British Columbia, Vancouver, Canada.
Elife
|August 1, 2018
Summary
Researchers discovered that Rap2 GTPase and TNIK regulate synapse formation downstream of Plexin in C. elegans. This pathway is crucial for correct synapse patterning and tiling during neural development.
Area of Science:
- Neuroscience
- Developmental Biology
- Cell Biology
Background:
- Neurons establish specific synaptic connections during development.
- Extracellular signals regulate synapse specificity, but intracellular mechanisms are less understood.
Purpose of the Study:
- To investigate the intracellular mechanisms of synapse specificity regulation.
- To identify downstream effectors of Plexin in controlling synapse formation and patterning.
Main Methods:
- Genetic analysis in *C. elegans*.
- Studying mutants for *rap-2* (Rap2 GTPase) and *mig-15* (TNIK).
- Investigating the genetic interaction between *plx-1* (Plexin) and *rap-2*.
Main Results:
- Rap2 GTPase and TNIK act downstream of Plexin to restrict presynaptic assembly.
- Rap2 nucleotide cycling is critical for synapse inhibition, as shown by constitutive Rap2 mutant phenotypes.
- Plexin suppresses local Rap2 activity, and TNIK acts as a negative regulator of synapse formation.
Conclusions:
- Subcellular regulation of Rap2 GTPase activity by Plexin is essential for proper synapse patterning.
- The Plexin-Rap2-TNIK pathway controls synaptic tiling and inhibits ectopic synapse formation.
Related Concept Videos
01:12Synaptic Signaling
79.8K
Neurons communicate at synapses, or junctions, to excite or inhibit the activity of other neurons or target cells, such as muscles. Synapses may be chemical or electrical.
79.8K
01:09Synaptic Signaling
6.7K
Neurons communicate at synapses, or junctions, to excite or inhibit the activity of other neurons or target cells, such as muscles. Synapses may be chemical or electrical.
Most synapses are chemical, meaning an electrical impulse or action potential spurs the release of chemical messengers called neurotransmitters. The neuron sending the signal is called the presynaptic neuron, and the neuron receiving the signal is the postsynaptic neuron.
The presynaptic neuron fires an action potential that...
Most synapses are chemical, meaning an electrical impulse or action potential spurs the release of chemical messengers called neurotransmitters. The neuron sending the signal is called the presynaptic neuron, and the neuron receiving the signal is the postsynaptic neuron.
The presynaptic neuron fires an action potential that...
6.7K
01:21Frequency-dependent Selection
24.1K
When the fitness of a trait is influenced by how common it is (i.e., its frequency) relative to different traits within a population, this is referred to as frequency-dependent selection. Frequency-dependent selection may occur between species or within a single species. This type of selection can either be positive—with more common phenotypes having higher fitness—or negative, with rarer phenotypes conferring increased fitness.
24.1K
01:17Drug Dependence
1.7K
Medications are typically administered to achieve therapeutic effects. Some drugs can modify an individual's mood and perception, frequently resulting in various enjoyable experiences. However, this can result in drug dependency, a condition marked by continuous drug use despite potential negative consequences. Drug dependency primarily falls into two categories: psychological and physical dependence. Psychological dependence occurs when the pleasurable feelings induced by the drug...
1.7K
01:19Contact-dependent Signaling
47.6K
Contact-dependent signaling, as the name suggests, requires that communicating cells be in direct contact with each other. This is achieved either through receptor-ligand interactions or by specialized cytoplasmic channels that allow the flow of small molecules between cells. In animal cells, channels called gap junctions facilitate contact-dependent signaling in certain tissues, whereas, plasmodesmata perform a similar function in plants.
Gap Junctions
In animal cells, gap junctions are formed...
Gap Junctions
In animal cells, gap junctions are formed...
47.6K
01:28Integration of Synaptic Events
4.1K
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...
4.1K