How do we remember a phone number we were just about to call?
How do we remember a phone number we were just about to call? How do we memorize the contents of a lecture or a movie? Already Plato and Aristotle asked how memory is stored as changes in the brain. In a new study, Professor Peter Jonas and his group at the Institute of Science and Technology Austria (IST Austria), including first author David Vandael, found that short-term memory may be formed by storing vesicles of neurotransmitter. These vesicle pools could be an “engram,” a physical trace of memory. The study is published in the journal Neuron.
Forming memory is essential for us to learn and acquire knowledge. In the 20th century, Richard Semon introduced the idea of an “engram,” a physical substrate of a memory: as an animal learns, information is stored in an engram in the brain. Later, this information is retrieved. “Where are the engrams? This was one of the questions we asked”, explains Peter Jonas. “Synaptic plasticity, the strengthening of communication between neurons, explains memory formation at the subcellular level. To find the engram, we, therefore, explored structural correlates of synaptic plasticity.”
Unexpected mechanism strengthens communication
For this search, postdoc David Vandael studied single synapses in the hippocampus, the brain area required for learning and memory. Among the many synapses that connect with a pyramidal cell neuron in the hippocampus, Vandael picked out one and recorded what happens as a granule cell sends a signal to the pyramidal cell it connects with. “Recording from single identified synapses is crucial. We, therefore, set up a close-to-impossible experiment, in which we made simultaneous recordings of electrical signals from a small pre-synaptic terminal and its postsynaptic target neuron. This is the perfect way to examine the synapse”, Vandael illustrates.
Read more at Institute of Science and Technology Austria
Photo Credit: Alexas_Fotos via Pixabay
