PKMzeta
Via Kevin Drum, the story of the stuff long term memories are made of. It seems that the archives of memory must be constantly tended at the molecular level, and the archivist is a molecule called PKMzeta. What does PKMzeta do? The molecule’s crucial trick is that it increases the density of a particular type of sensor called an AMPA receptor on the outside of a neuron. It’s an ion channel, a gateway to the interior of a cell that, when opened, makes it easier for adjacent cells to excite one another. (While neurons are normally shy strangers, struggling to interact, PKMzeta turns them into intimate friends, happy to exchange all sorts of incidental information.) This process requires constant upkeep—every long-term memory is always on the verge of vanishing. As a result, even a brief interruption of PKMzeta activity can dismantle the function of a steadfast circuit. If the genetic expression of PKMzeta is amped up—by, say, genetically engineering rats to overproduce the stuff—the...