Reduction in phosphorylated heavy neurofilament in the cerebellum in HIV disease.

In the absence of significant neuronal infection HIV induces neuronal damage and death. The pathogenesis of this process is not clear and can only be assessed in the HIV infected brain by examining surviving neuronal populations. Cerebellar Purkinje cells are a model population. We have already demonstrated glutamate receptor alterations in these neurons in AIDS, and in the current study we have investigated the phosphorylation status of heavy neurofilament (NF-H), which is under the control of various intracellular kinases. While the number of Purkinje cells expressing non-phosphorylated NF-H was unchanged, the number of Purkinje cells expressing phosphorylated NF-H was decreased by 36% in the HIV group. This may be a marker of neuronal damage, and possibly indicate alteration in the activity of various intracellular signalling kinase pathways in the HIV infected brain.