TNF alpha gene expression is induced in neurones after a hippocampal lesion.

The tumour necrosis factor alpha (TNF alpha) protein is normally absent in the brain. Its production in the nervous tissue during pathological processes is commonly attributed to cells of the macrophage or astroglial lineages. However, an immunoreactivity for TNF alpha has been observed recently in adult mouse brain after a lesion to the hippocampus. The identification, in the present study, of the cells responsible for this synthesis demonstrates a neuronal localization of the TNF alpha messenger RNA. We propose that neurone-produced TNF alpha acts as a modulatory effector in post-traumatic regenerative attempts of the brain.