Related Experiment Video
Updated: Feb 10, 2026
08:30
Imaging Odor-Evoked Activities in the Mouse Olfactory Bulb using Optical Reflectance and Autofluorescence Signals
Published on: October 31, 2011
16.6K
Sema7A/PlxnCl signaling triggers activity-dependent olfactory synapse formation
Nobuko Inoue1, Hirofumi Nishizumi1, Hiromi Naritsuka2
1Department of Brain Function, University of Fukui School of Medicine, 23-3 Shimo-aizuki, Matsuoka, Fukui, 910-1193, Japan.
Nature Communications
|May 11, 2018
Summary
Neural activity shapes brain circuits. In mice, Sema7A signaling and PlxnC1 interaction are crucial for forming new connections in the olfactory system during early development.
Area of Science:
- Neuroscience
- Developmental Biology
- Molecular Biology
Background:
- Neural circuits in mammals develop via genetic programs and are refined by neonatal neuronal activity.
- The mouse olfactory system's glomerular map undergoes activity-dependent refinement and new connections.
Purpose of the Study:
- To investigate the role of Sema7A and PlxnC1 in activity-dependent synapse formation and dendrite selection in the neonatal mouse olfactory system.
- To elucidate the molecular mechanisms underlying the formation of second-order neuronal connections.
Main Methods:
- Analysis of Sema7A and PlxnC1 expression patterns in olfactory sensory neurons (OSNs) and mitral/tufted (M/T) cells.
- Utilizing knockout (KO) mouse models for Sema7A and PlxnC1.
- Performing reconstitution and rescue experiments.
- Employing pharmacological blocking of synaptic transmission.
Main Results:
- Sema7A is expressed in OSNs in an activity-dependent manner, while PlxnC1 is found on M/T cell dendrites.
- Sema7A or PlxnC1 KO mice exhibited perturbed synapse formation and M/T cell dendrite selection.
- Sema7A-PlxnC1 interaction is essential for post-synaptic assembly.
- Synaptic transmission triggers primary dendrite selection through synaptic competition.
Conclusions:
- Sema7A signaling is critical for inducing activity-dependent post-synaptic events.
- Sema7A signaling plays a key role in M/T cell dendrite selection during the neonatal period.
- This study reveals a novel mechanism for activity-dependent circuit formation in the olfactory system.
Related Concept Videos
02:47The Synapse
133.7K
Neurons communicate with one another by passing on their electrical signals to other neurons. A synapse is the location where two neurons meet to exchange signals. At the synapse, the neuron that sends the signal is called the presynaptic cell, while the neuron that receives the message is called the postsynaptic cell. Note that most neurons can be both presynaptic and postsynaptic, as they both transmit and receive information.
133.7K
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
01:16Calmodulin-dependent Signaling
6.2K
Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
6.2K
02:26NF-κB-dependent Signaling Pathway
10.1K
The transcription factor NF-κB was discovered in 1986 in the lab of Nobel laureate Professor David Baltimore, for its interaction with the immunoglobulin light chain enhancer in B-cells. After more than three decades of study, it is now evident that NF-κB regulates the expression of over 100 genes. Most of these genes play an essential role in the innate and adaptive immune responses as well as the inflammatory responses of animals.
NF-κB-dependent Signaling Mechanism
The...
NF-κB-dependent Signaling Mechanism
The...
10.1K
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
02:03What is Cell Signaling?
131.1K
Despite the protective membrane that separates a cell from the environment, cells need the ability to detect and respond to environmental changes. Additionally, cells often need to communicate with one another. Unicellular and multicellular organisms use a variety of cell signaling mechanisms to communicate to respond to the environment.
131.1K