Amazing Hungarian discovery: this is how the brain creates negative memories

Hungarian researchers have discovered a group of neurons in the brain stem that are responsible for storing and recalling negative memories.

Hungarian discovery

Researchers at the ELKH Research Institute of Experimental Medicine (KOKI) have discovered that a group of brainstem neurons, thought to be evolutionarily ancient, is also required for the storage and retrieval of negative memories.

The researchers’ findings show that memory processes are not only controlled by higher order brain cortex, but also by a hitherto less-studied brainstem. This discovery by the Hungarian researchers could set a completely new direction for future memory research.

Memories are encoded by a precise pattern of activity of millions of neurons in an area of the cerebral cortex called the hippocampus. “Although the hippocampus links our negative experiences to the environment in which we experienced them, we can also consciously control their severity and our memories of them. These are not only generated by the association between the bad experience and the environment, but are also influenced by a number of prior memories, assumptions, current mood, physiological state of the body and other circumstances,” the researchers said.

Groundbreaking result by Hungarian scientists

We already knew that environmental information is transmitted from the cerebral cortex to the hippocampus. However, the processes and pathways were not known to researchers until now. The Hungarian team, by Gábor Nyiri, has made a pioneering discovery in this area, napi.hu reports.

“When a memory is recorded, some hippocampal principal cells need to be activated, while others need to be inhibited to form the memory trace. The activity pattern of these cells depends on a number of factors. For example, the sensory information they receive from the cortex and the internal processes they associate with,” the researchers explained.

Processing negative memories

KOKI researchers have shown that a group of cells called nucleus incertus, which send nerve fibres to the hippocampus, play a pivotal role in the recall of negative experiences.

They demonstrated that their activation alone did not cause any adverse experience. On the contrary, if the same brainstem cells were activated when the unfavourable experience was recorded, their subsequent reactivation made it possible to recall that negative input.