Health researchers from Japan have discovered neurons in our brain’s hypothalamus region, whose inhibition during rapid eye movement (REM) sleep is connected to removing the ‘unnecessary’ memories from the brain, as per a new study published in the journal Science. The results provide information about mechanisms behind the regulation of memory during our sleep.
When we sleep, our brain continues to work and it processes all the information that we gather during the day and classifies and consolidates them into memories, the study said.
However, not all the day’s experiences are worth remembering so it is necessary to forget for our memory regulation. The process of removing unwanted memories is termed as synaptic renormalisation which only occurs during our sleep.
A group of researchers headed by Shuntaro Izawa from Japan’s Nagoya University analysed and studied the role of a specific set of nerve cells that are called the Melanin-concentrating hormone (MCH). These MCH neurons are found only in the brain’s hypothalamus and play a role in the regulation of sleep and wakefulness, and the time spent in the REM sleep.
The research team found that inhibition of the MCH neurons increased the memory in mice, while the activation of MCH neurons impaired memory.
Hence, the results from the study suggested that the REM sleep neural pathway plays a key role in our active forgetting. The researchers mentioned that MCH pathways could be used as a target for memory modulation.