Expression and Function
Neurexins are diffusely distributed in neurons and become concentrated at presynaptic terminals as neurons mature. There exists a trans-synaptic dialog between neurexin and neuroligin, meaning neuroligin can induce the expression of neurexin and vise versa. This bi-directional trigger aids in the formation of synapses and is a key component to modifying the neuronal network. Over-expression of either of these proteins causes an increase in synapse forming sites, thus providing evidence that neurexin plays a functional role in synaptogenesis. Conversely, the blocking of β-neurexin interactions reduces the number of excitatory and inhibitory synapses. It is not clear how exactly neurexin promotes the formation of synapses. One possibility is that actin is polymerized on the tail end of β-neurexin, which traps and stabilizes accumulating synaptic vesicles. This forms a forward feeding cycle, where small clusters of β-neurexins recruit more β-neurexins and scaffolding proteins to form a large synaptic adhesive contact.
Read more about this topic: Neurexin
Famous quotes containing the words expression and/or function:
“You have to begin to lose your memory, if only in bits and pieces, to realize that memory is what makes our lives. Life without memory is no life at all, just as an intelligence without the possibility of expression is not really an intelligence. Our memory is our coherence, our reason, our feeling, even our action. Without it, we are nothing.”
—Luis Buñuel (1900–1983)
“... the function of art is to do more than tell it like it is—it’s to imagine what is possible.”
—bell hooks (b. c. 1955)