A new study from Karolinska Institutet, published in the scientific journal Brain, suggests that particular proteins important in the communication between neurons could be targets for early interventions in patients with different types of dementias.

One of the most intriguing properties of the brain is its means to undergo synaptic plasticity which represents the basis for learning and memory, abilities that severely decline in the case of a dementia.

In the nervous system, a synapse is the place where signals are passed from neuron to neuron. The current study focuses on synaptic dysfunction and its impact on dementia severity and cognition in the elderly with various dementia diagnoses.

In addition to Alzheimer's disease, the Lewy body dementias are the most common forms of neurodegenerative dementias with a very severe prognosis. Synaptic loss, a prominent feature in Alzheimer's disease is strongly correlated with dementia severity. Much less is known regarding synaptic loss in Lewy body dementias.

"Our findings suggest that particular pre- and postsynaptic proteins have an important predictive and discriminative molecular fingerprint in neurodegenerative diseases and represent potential targets for early disease intervention, such as synaptic regeneration," said first author Erika Bereczki says of Karolinska Institutet, Sweden.

The study is the first in-depth quantitative proteome study on pre-frontal post-mortem brain tissues where beside the whole proteome comparison, the researchers also profiled the entire synaptic proteome of Alzheimer's disease, Parkinson's disease with dementia and dementia with Lewy bodies patients and compared them to control cases.

Taking benefit of the technological advance of proteomics analyses (a technique for large-scale studies of proteins) Erika Bereczki and her colleagues have identified key synaptic proteins underlying synaptic dysfunction which were associated with the degree of cognitive decline across dementias.

"Our results suggest shared mechanisms, with major implications for prognostic and diagnostic marker development as well as advancing future therapeutic interventions for improving the disease course. This places synaptic dysfunction and repair approaches in the spotlight of attention, especially since the therapeutic intervention window for synaptic repair and regeneration is longer than the recent toxin-clearance approaches", Erika Bereczki says.