Summary: A Nature Communications study reveals the activity of dendrites increase as we sleep. This increased activity could be key to how we are able to form memories.
Source: University of Surrey.
A study has given new insights into how sleep contributes to brain plasticity – the ability for our brain to change and reorganise itself – and could pave the way for new ways to help people with learning and memory disorders.
Researchers at the Humboldt and Charité Universities in Berlin, led by Dr Julie Seibt from the University of Surrey, used cutting edge techniques to record activity in a particular region of brain cells that is responsible for holding new information – the dendrites.
The study, published in Nature Communications, found that activity in dendrites increases when we sleep, and that this increase is linked to specific brain waves that are seen to be key to how we form memories.
Dr Julie Seibt, Lecturer in Sleep and Plasticity at the University of Surrey and lead author of the study, said: “Our brains are amazing and fascinating organs – they have the ability to change and adapt based on our experiences. It is becoming increasingly clear that sleep plays an important role in these adaptive changes. Our study tells us that a large proportion of these changes may occur during very short and repetitive brain waves called spindles.
“Sleep spindles have been associated with memory formation in humans for quite some time but nobody knew what they were actually doing in the brain. Now we know that during spindles, specific pathways are activated in dendrites, maybe allowing our memories to be reinforced during sleep.
“In the near future, techniques that allow brain stimulation, such as transcranial magnetic stimulation (TMS), could be used to stimulate dendrites with the same frequency range as spindles. This could lead to enhance cognitive functions in patients with learning and memory disorders, such as dementia.”
Source: Dalitso Njolinjo – University of Surrey
Image Source: NeuroscienceNews.com image is in the public domain.
Original Research: Full open access research for “Cortical dendritic activity correlates with spindle-rich oscillations during sleep in rodents” by Kathryn L. Heinze and Di Lu in Nature Communications. Published online September 25 2017 doi:10.1038/s41467-017-00735-w
Cortical dendritic activity correlates with spindle-rich oscillations during sleep in rodents
How sleep influences brain plasticity is not known. In particular, why certain electroencephalographic (EEG) rhythms are linked to memory consolidation is poorly understood. Calcium activity in dendrites is known to be necessary for structural plasticity changes, but this has never been carefully examined during sleep. Here, we report that calcium activity in populations of neocortical dendrites is increased and synchronised during oscillations in the spindle range in naturally sleeping rodents. Remarkably, the same relationship is not found in cell bodies of the same neurons and throughout the cortical column. Spindles during sleep have been suggested to be important for brain development and plasticity. Our results provide evidence for a physiological link of spindles in the cortex specific to dendrites, the main site of synaptic plasticity.
“Cortical dendritic activity correlates with spindle-rich oscillations during sleep in rodents” by Kathryn L. Heinze and Di Lu in Nature Communications. Published online September 25 2017 doi:10.1038/s41467-017-00735-w