Virtual brain gives insights into memory deficits in depression

June 11, 2018, Ruhr-Universitaet-Bochum
Sen Cheng analyzes brain functions with the aid of computer models. Credit: RUB, Marquard

During a depressive episode, the ability of the brain to form new brain cells is reduced. Scientists of the Ruhr-Universität Bochum examined how this affects the memory with a computational model. It was previously known that people in an acute depressive episode were less likely to remember current events. The computational model however suggests that older memories were affected as well. How long the memory deficits reach back depends on how long the depressive episode lasts. The team around the computational neuroscientist Prof Dr. Sen Cheng published their findings in the journal PLOS ONE on 7th June 2018.

Computational model simulates a depressive brain

In major depressive disorder, patients may suffer from such severe cognitive impairments that, in some cases, are called pseudodementia. Unlike in the classic form of dementia, in pseudodementia, recovers when the ends. To understand this process, the scientists from Bochum developed a computational model that captures the characteristic features of the brain of a patient with depression. They tested the ability of the model to store and recall new memories.

As is the case in patients, the simulation alternated between depressive episodes and episodes without any symptoms. During a depressive episode, the brain forms fewer new neurons in the model. Whereas in previous models, memories were represented as static patterns of neural activity, the model developed by Sen Cheng and his colleagues views memories as a sequence of neural activity patterns. "This allows us not only to store events in memory, but also their temporal order," says Sen Cheng.

Impact on brain stronger than thought

The computational model was able to recall memories more accurately if the responsible brain region was able to form many new neurones, just like the scientists expected. However, if the brain region formed fewer new cells, it was harder to distinguish similar memories and to recall them separately.

The not only showed deficits in recalling current events, it also struggled with memories that were collected before the depressive episode. The longer the depressive episode lasted, the further the memory problems reached back.

"It was previously assumed that memory deficits only occur during a depressive episode," says Sen Cheng. "If our is right, could have consequences that are more far-reaching. Once remote memories have been damaged, they do not recover, even after the depression has subsided."

Explore further: New method to identify causal mechanisms in depression

More information: Jing Fang et al, The reduction of adult neurogenesis in depression impairs the retrieval of new as well as remote episodic memory, PLOS ONE (2018). DOI: 10.1371/journal.pone.0198406

Related Stories

New method to identify causal mechanisms in depression

December 6, 2017
People with major depressive disorder have alterations in the activity and connectivity of brain systems underlying reward and memory, according to a new study in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging. ...

Cognitive training reduces depression, rebuilds injured brain structure and connectivity after traumatic brain injury

May 30, 2018
New research from the Center for BrainHealth at The University of Texas at Dallas shows that certain cognitive training exercises can help reduce depression and improve brain health in individuals years after they have suffered ...

People with depression have stronger emotional responses to negative memories

March 6, 2018
People with major depressive disorder (MDD) feel more negative emotion when remembering painful experiences than people without the disorder, according to a new study in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging. ...

Scientists identify the segmentation and consolidation mechanism of long-term memories

November 28, 2017
A study led by the Bellvitge Biomedical Research Institute (IDIBELL) has identified a neural mechanism that allows humans to segment experience into discrete memory units. According to the research, published in the scientific ...

How odours are turned into long-term memories

December 22, 2017
The neuroscientists Dr. Christina Strauch and Prof Dr. Denise Manahan-Vaughan from the Ruhr-Universität Bochum have investigated which brain area is responsible for storing odours as long-term memories. Some odours can trigger ...

Susceptibility for relapsing major depressive disorder can be calculated

October 22, 2014
The question if an individual will suffer from relapsing major depressive disorder is not de-termined by accident. Neuroscientists from the Mercator Research Group 'Structure of Memory' have chosen a new research approach, ...

Recommended for you

New study finds 'timing cells' in the brain may underlie an animal's inner clock

October 23, 2018
Are you taking your time when feeding your pet? Fluffy and Fido are on to you—and they can tell when you are dawdling.

Neurons reliably respond to straight lines

October 23, 2018
Single neurons in the brain's primary visual cortex can reliably detect straight lines, even though the cellular makeup of the neurons is constantly changing, according to a new study by Carnegie Mellon University neuroscientists, ...

Scientists reveal new details of how a naturally occurring hormone can boost memory in aging mice

October 23, 2018
A Columbia study in mice has revealed new details of how a naturally occurring bone hormone reverses memory loss in the aging brain. These findings about the hormone, called osteocalcin, stand to spur further investigations ...

Mutation in common protein triggers tangles, chaos inside brain cells

October 23, 2018
A pioneer in the study of neural cells revealed today (Oct. 23, 2018) how a single mutation affecting the most common protein in a supporting brain cell produces devastating, fibrous globs. These, in turn, disturb the location ...

Nerve-on-a-chip platform makes neuroprosthetics more effective

October 23, 2018
EPFL scientists have developed a miniaturized electronic platform for the stimulation and recording of peripheral nerve fibers on a chip. By modulating and rapidly recording nerve activity with a high signal-to-noise ratio, ...

The smell of lavender is relaxing, science confirms

October 23, 2018
Lavender works its relaxing magic all around us: from garden borders to bath bombs to fabric softener. But why not in our hospitals and clinics? And what is the science behind the magic?

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.