Scientists have discovered a unique signaling mechanism in brain cells that uses a “muscle-like” process to relay information over long distances. The research, led by the Lippincott-Schwartz Lab, found that dendrites, the branch-like extensions of neurons, contain a network of contact sites that amplify calcium signals similar to how muscles contract.
These contact sites regulate calcium release, activating key proteins involved in learning and memory. The findings explain how neurons process information received at specific points and relay it to the cell body. Understanding this process sheds light on synaptic plasticity, which underlies learning and memory formation.
The researchers found that the molecular machinery controlling calcium release at muscle cells’ contact sites is also present at dendrite contact sites. This led them to suspect that the contact sites along the dendrites might act like a repeater on a telegraph machine, receiving, amplifying, and propagating signals over long distances.
They discovered that the process involves calcium entering the dendrite through voltage-gated ion channel proteins, triggering the release of additional calcium from the ER at the contact site. This influx of calcium activates CaMKII, a protein important in memory, altering the plasma membrane’s biochemical properties and changing the strength of the signal passed down.
The study reveals a novel mechanism for signal transmission in brain cells, helping to answer an open question in neuroscience about how intracellular signals travel over long distances in neurons. It also sheds light on the molecular mechanisms underlying synaptic plasticity, enabling learning and memory.
Source: https://neurosciencenews.com/dendrite-memory-learning-muscle-28406