How are odours stored as long-term memories?

Have you ever had a flashback of a memory when you smell a particular odour?

The small of a specific fragrance or mum’s baking or even an odour you don’t like can trigger a long-term memory.

Previous studies have shown that a part of the brain – the piriform cortex is able to temporarily store these memories but does it also store long-term olfactory memories?

This time the stimulation of the brain area resulted in a change in the piriform cortex indicating that the piriform cortex can store long-term memories but with the help of a higher brain region to instruct it.

To find out, neuroscientists from Ruhr-Universität Bochum conducted mice studies in which they used electrical impulses in the brain to emulate the processes which trigger memory formation of the olfactory kind.

Synaptic plasticity is responsible for the storing of memories in the memory structures of the brain – during which the communication between the neurons is altered thus leading to memory creation.

The scientists used different stimulation protocol which varies in frequency and intensity of pulses. It has been known that these stimulation pulses induce long-term information storage in the hippocampus – another region of the brain responsible for long-term memories.

However, these stimulations did not cause long-term information storage in the form of synaptic plasticity in the piriform complex.

This made the scientists wonder if the piriform cortex needed instructions in creating long-term memories. The scientists then stimulated a higher brain area called the orbitofrontal cortex – a region responsible for discriminating between sensory experiences.

This time the stimulation of the brain area resulted in a change in the piriform cortex indicating that the piriform cortex can store long-term memories but with the help of a higher brain region to instruct it to store events as long-term memories.

Now we know how memories associated with odours are stored in the brain which can be recalled when we smell something specific.

Source: Cerebral Cortex