Abnormal accumulation of free zinc ions in neurons of patients after traumatic brain injury/acute ischemia/epilepsy by immersion autometallography

Abstract

Objective To study the distributions of flee zinc ions in the neurons of patients after traumatic brain injury/acute ischemia/epilepsy and to provide morphological evidence of involvement of zinc ions in the neuronal injury. Methods Fresh cortex specimens from patients suffered from brain trauma （n=5）, acute ischemia （n=3） and epilepsy（n=3） were collected during the surgeries. Immersion autometallograpby was used to detect the free zinc ions in the neurons, and HE staining was employed to observe the morphological changes of the neurons. Results Pathological zinc accumulation was extensively presented in the neurons of patients after ischemia, epilepsy and mechanical head trauma. Zinc-positive products were predominantly located in the neural bodies and the axon terminals, and could not be seen in the glial cells and the neurons of normal cortex. HE staining indicated that apparently damaged neurons were observed in all of the brain regions with zinc ions labeled neuronal somata. Conclusion zinc ions might play important roles in the neurons of patients after brain trauma, acute ischemia and epilepsy and be actively involved in these acute neural pathological processes. Key words: Zinc; Immersion autometallography; Traumatic brain injury; Ischemia; Epilepsy; Neuron