United States: As we understand, the virus causing cold sores – herpes simplex virus type 1 (HSV-1 )is capable of penetrating the brain, and the central nervous system (CNS), and a new study reveals how the viral attack extends.
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Working with researchers from the University of Colorado and the University of Bourgogne in France, the study paid particular attention to the impact of the HSV-1 virus on the brains of mice and the areas that could be affected, analyzing the possible consequences of the condition.
HSV-1 can penetrate into the CNS through the trigeminal or olfactory nerves in the first instance, but the way in which the virus disseminates within the brain is still unexplained.
According to neurologist Christy Niemeyer from the University of Colorado, “Recently, this common virus has been implicated in neurodegenerative diseases, such as Alzheimer’s disease, but no clear route of central nervous system invasion has been established,” sciencealert.com.
“Identifying how HSV-1 can get into the brain and what brain regions are vulnerable is key in understanding how it initiates disease,” Niemeyer reported.
More findings
The team was able to show that HSV-1 became established in several of the brain’s key areas, such as the brain stem, which controls heart and breath rate, sleep, and movement, as well as the hypothalamus, which deals with sleep, moods, appetite, and hormones.
However, many parts of the brain did not have an HSV-1 antigen in them, and these included the hippocampus, which is responsible for memory or special navigation, often linked to diseases of Alzheimer’s, and the cortex, which is related to memory and attention.
The researchers also investigated the activation of microglia – resident immune cells of the central nervous system – in mouse brains, and these cells became activated as soon as they came into contact with HSV-1.
In some areas of the lungs, these immune cells remained active after the virus had cleared, a sign of inflammation.
However, at its worst, HSV-1 can lead to developing encephalitis, an inflammation that includes the entire brain.
Even if this did not happen here, the research indicates that there might still be harm being caused.
As per Niemeyer, “Even though the presence of HSV-1 is not causing full-blown encephalitis in the brain, it can still affect how these regions function,” sciencealert.com reported.