Complexin…not so inconsequential anymore

Researchers at MIT’s Picower Institute for Learning and Memory may have found the key to controlling how the brain is wired while studying the bursts of activity that occur after communication between neurons.

First, I will give an overview of neural communication. Neural cells communicate with each other at a synapse, which is the point of contact between the cells at which signals are transmitted. The action potential stimulates the input cell (presynaptic) to release neurotransmitters. These neurotransmitters travel across the synaptic cleft and bind to neurotransmitter receptors on the receiving (postsynaptic) cell. However, the action of the neurotransmitter needs to be controlled so that the cell is not continually activated.

That is where this new research, conducted by Sarah Huntwork and J Troy Littleton, comes in. These scientists have identified a molecule, called complexin, which acts as a gatekeeper to help control the release of neurotransmitters. As it turns out, a few cells will continue to release neurotransmitters even after the major electrical stimulus has passed. They call these events “minis”, which are regulated by complexin. However, they have discovered that in the absence of complexin, these minis can occur without regulation, and when they do, it can lead to rewiring of the brain and synaptic growth.

So what does this mean in terms of neurological diseases? The activity of complexin can be controlled, and if properly regulated, may allow synaptic growth to be stimulated and rewiring of the brain to occur.


  1. #1 Blake Stacey
    September 20, 2007


    Neural Darwinism, perhaps?

    I learned a new unit today from reading that Nature Neuroscience article: a “mini” is what you get when a single vesicle of neurotransmitter dumps into a synapse!

  2. #2 Ichthyic
    September 20, 2007


    shall we call this evidence of Irreducible Complexin?

    (sorry, but somebody had to).

  3. #3 Torbjörn Larsson, OM
    September 21, 2007

    So there is a certain tension between normal functioning of neurons and synaptic growth. Not exactly what I would call “nice” :-P, but understandable and interesting.

    I’m sorry, but actually I found a more fascinating item on development today, the press release describing results on how nuclear membrane forms during mitosis. I have a vague memory of the disassembling-assembling hypothesis and the machinery it required to evenly divide and reform the nuclear membrane.

    But what actually happens makes more sense, a natural folding and binding of ER tubules around the chromatin. Perhaps PZ can get some evo-devo mileage out of that, or at least find some analogy to embryonic tissue layers.

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