Synapses recycle proteins for the release of neurotransmitters

Neurons communicate via chemical transmitters which they store in the bubble-like synaptic vesicles and release as required. To be able to react reliably to stimulation, neurons must have a certain number of "acutely releasable" vesicles.

 
The electrical activity of neurons can be measured using a tiny electrode tip (above). The cell body of the neuron, which is around 20 thousandths of a millimetre in size, appears green under the fluorescence microscope because it is filled with calcium-sensitive dye (below). Image: JeongSeop Rhee

With the help of a new method, neuroscientists at the Max Planck Institute of Experimental Medicine in Göttingen have now discovered that neurons systematically recycle the protein components necessary for transmitter release and in this way guarantee the reliability of signal transmission in the brain.

If this process is disrupted, the communication between the neurons quickly comes to a standstill and vital processes that rely on the rapid transmission of information, for example seeing or the instant identification of a sound source, become impossible to carry out. (Neuron, 4 November 2010)

The electrical activity of neurons can be measured using a tiny electrode tip (above). The cell body of the neuron, which is around 20 thousandths of a millimetre in size, appears green under the fluorescence microscope because it is filled with calcium-sensitive dye (below).

Neurons transmit signals to each other via specialised contacts known as synapses. When a transmitting neuron is excited, it releases chemical transmitters that are discharged by tiny membrane-enclosed vesicles and then reach the recipient cell.

The release of the transmitters is carried out through the fusion of the vesicles with the cell membrane - a process that requires the interaction of different protein components in the cell.