Hairstyle of a Neuron: From Hairy to Mushroom-Head

March 7, 2007
Hairstyle of a Neuron: From Hairy to Mushroom-Head
Transformation of a hairy filament (top) into a dendritic spine (bottom). The activation of a certain receptor leads to the formation of the "mushroom-like" head on the dendritic spine, shown in the lower picture. This enlarged area enables the transfer of information from one nerve cell to the next. Image: Max Planck Institute of Neurobiology

Synapses are essential for the brain's normal function: their absence or presence is tightly linked to the brain's ability to transfer, process, and store information. Synapses are thus constantly generated and degraded. However, the mechanisms of this complex remodelling process remained largely unknown. Scientists of the Max Planck Institute of Neurobiology have now identified the molecular players involved in synapse formation.

One of the most prominent traits of the brain is its ability to learn and to store information. To do so, nerve cells might need to either create new sites of contact, the synapses, or to disable such sites again. For example, an increase in synaptic contacts between nerve cells is attributed to learning, while their loss can signify the loss of information. As a consequence, the total number of synapses varies constantly - not only in the developing, but also in the adult brain. This synaptic plasticity is now known as one of the key mechanisms of learning and memory processes.

To form a new synapse, hair-like filaments on opposing nerve cells differentiate into dendritic spines, each composed of a stalk which supports a large head. Information transfer between nerve cells is then possible through these enlarged spine heads. However, the mechanisms that control this conversion of a thin filament into a functional dendritic spine have until now remained a mystery.

The Max Planck scientists Inmaculada Segura, Clara Essmann, Stefan Weinges and Amparo Acker-Palmer have succeeded in unravelling one of these complex mechanisms. To achieve this, they concentrated their investigations on a specific group of receptors and their membrane-bound binding partners. Amazingly, the binding partners can also function as receptors in this system. This "reverse signalling" plays an important role in the modification of the cytoskeleton and thus in the formation of dendritic spines. The Max Planck scientists were able to identify the molecular components which control this cytoskeleton remodelling. These exciting insights into the control of synapse formation advance our knowledge of the mechanisms involved in learning and information storage by one important step.

Citation: Inmaculada Segura, Clara L. Essmann, Stefan Weinges and Amparo Acker-Palmer
Grb4 and GIT1 transduce ephrinB reverse signals modulating spine morphogenesis and synapse formation. Nature Neuroscience, online publication from February 18th.

Source: Max Planck Society

Explore further: Scientists identify molecular mechanism behind early flowering

Related Stories

The logistics on the drosophila X chromosome

October 2, 2015

If we place an order in an online store we are often thrilled how fast the parcel is delivered to our doorstep. This is possible because logistic companies have established a very reliable and efficient system to distribute ...

Rules of communication in the nucleus

August 28, 2015

Nuclear pores in the nuclear membrane do not only control the transport of molecules into and out of the nucleus but also play an important role in gene expression. Researchers at the Max F. Perutz Laboratories (MFPL) of ...

Tracking nanowalkers with light

September 25, 2015

Nanotechnology is taking its first steps. Researchers from the Max Planck Institute for Intelligent Systems in Stuttgart have developed a gold nanocylinder equipped with discrete DNA strands as 'feet' that can walk across ...

Clever feedback system regulates immune responses

August 17, 2015

A newly discovered feedback mechanism in the body is responsible for keeping immune responses from getting out of hand. It works at the level of certain genes, linking the inactivation of those genes to the progress made ...

Recommended for you

How the finch changes its tune

August 3, 2015

Like top musicians, songbirds train from a young age to weed out errors and trim variability from their songs, ultimately becoming consistent and reliable performers. But as with human musicians, even the best are not machines. ...

Machine Translates Thoughts into Speech in Real Time

December 21, 2009

( -- By implanting an electrode into the brain of a person with locked-in syndrome, scientists have demonstrated how to wirelessly transmit neural signals to a speech synthesizer. The "thought-to-speech" process ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.