Brain structures selectively targeted by canine distemper virus in a mouse model infection

Area of Science:

• Neurovirology
• Central Nervous System Diseases
• Viral Pathogenesis

Background:

• Paramyxoviruses, including canine distemper virus (CDV), cause acute and chronic encephalitis.
• Mechanisms of viral-induced neurological damage remain unclear.
• CDV is an etiological agent for chronic distemper encephalitis (old dog encephalitis).

Purpose of the Study:

• To develop a mouse model for analyzing CDV spatial and temporal distribution in the central nervous system (CNS).
• To identify cerebral target structures for viral replication during acute and subacute disease stages.
• To elucidate viral injury mechanisms leading to neurological diseases.

Main Methods:

• Experimental infection of mice with CDV via intracranial or intracerebroventricular routes.
• Analysis of viral material (proteins and mRNA) distribution in CNS structures.
• Examination of viral presence during acute (day 6) and subacute (up to 4-6 weeks) disease phases.

Main Results:

• During the acute stage, viral mRNA and proteins were localized in specific brain areas: thalamus, hypothalamus, substantia nigra, locus ceruleus, raphe nuclei, and limbic system.
• The virus did not replicate in cerebellum, striatum, most cortical areas, or endothelial cells.
• In the subacute stage, viral material was mostly undetectable, except in the hypothalamus, despite ongoing pathology (obesity, paralysis).

Conclusions:

• CDV replication is restricted to specific CNS structures during the acute phase.
• Neurological and neuroendocrine diseases may result from viral gene expression disrupting homeostasis, even after viral clearance.
• The study highlights the potential for long-term neurological consequences from transient viral presence.