Lesions of the locus coeruleus system aggravate ischemic damage in the rat brain.

The possibility that the noradrenergic locus coeruleus system influences brain damage following ischemia was explored in rats. Bilateral lesions of the locus coeruleus projections to the forebrain aggravated the neuronal necrosis in the hippocampal CA1 region and neocortex following complete cerebral ischemia induced by transient cardiac arrest. These findings provide evidence that the postischemic activation of the inhibitory locus coeruleus system could counteract a possible detrimental neuronal hyperexcitation, thereby limiting neuronal necrosis.