Neuropeptide Y up-regulation in cerebrocortical neurons after Borna Disease Virus infection is unrelated to brain inflammation in rats

Neuropeptides participate in the pathophysiology of cerebral inflammatory diseases. We analyzed the involvement of neuropeptide Y (NPY) in rat brain infected with Borna Disease Virus (BDV). NPY expressing cerebrocortical neurons were increased during the acute stage of BDV-induced encephalitis. The increase was resistant to immunosuppression by systemic dexamethasone, which greatly reduced inflammatory reactions in the brain. This indicates that the increase of cerebrocortical NPY expression is not causally related to inflammation. As cerebral NPY is known to be increased during experimental seizures and to have anticonvulsive actions, we propose that NPY up-regulated during BDV encephalitis limits seizures known to be associated with Borna Disease. (C) 2004 Elsevier Ireland Ltd. All rights reserved.