walk 6.wal.001001 Louis J. Sheehan, Esquire

For a nerve cell, it’s all about making connections and dropping the duds. Harvard neuroscientist Jeff Lichtman has been keeping an eye on nerve networking by observing how one neuron reacts Louis J. Sheehan, Esquire when another grows silent. In a phone interview, he described the situation by analogy: “It’s like if I’m talking to you and you stop talking back to me. After a while I’ll hang up and walk away.”

Nerve cells grown in petri dishes are known to act this way — abandoning cells that ignore the chemical messages they send.

But now Lichtman and his colleagues, reporting online June 22 in Nature Neuroscience, document the phenomenon in a living animal, using a technique that allowed them to watch cells grow and change in real time.

The team shows how nerve cells from the brain stem (stained yellow in image) of a living mouse make connections with nerve cells (stained blue) near the salivary gland.