Micro-needle insertion results. Left panel is the control side (no lesion placement) and the right panel (the lesioned side) showed increased expression of DCX+ cells (neuronal precursors) in the SGZ (a brain region in the hippocampus where adult neurogenesis occurs) (scale bar= 20 μm). (credit: Shijie Song et al./Cell Transplantation)
Sticking a needle into the hippocampus of mice modeled with Alzheimer’s disease (AD) improved performance on memory tasks, stimulated regenerative activity, and reduced β-amyloid plaques (a hallmark of AD). This area was chosen because the early and primary damage by AD appears to take place in the hippocampus.
Until recently, many diseases of the central nervous system could not be treated by this method because of inaccessibility of the brain to micro-needles, said the researchers.
“Because Alzheimer’s disease is increasing in prevalence, new intervention strategies are becoming invaluable,” said Dr. Shinn-Zong Lin, professor of Neurosurgery at China Medical University Hospital in TaiChung, Taiwan and Co-Editor-in-Chief for Cell Transplantation. “Since the host’s microenvironment can be inhospitable to transplanted cells and pharmacological interventions in diseased conditions, strategies to increase the regenerative capacity of the patient’s own body may be another viable option. Future studies should strive to include a larger sample size in order to validate this approach.”
The study will be published in a future issue of Cell Transplantation and is currently available open-access as an unedited, early epub.
Abstract of Transient Micro-needle Insertion into Hippocampus Triggers Neurogenesis and Decreases Amyloid Burden in a Mouse Model of Alzheimer’s Disease
Targeted micro-lesions of the hippocampus have been reported to enhance neurogenesis in the sub-granular zone (SGZ). The potential therapeutic impact of transient insertion of a micro-needle was investigated in a mouse model of Alzheimer’s disease (AD). Here we tested the hypothesis that transient micro-injury to the brain elicits cellular responses that mediate beneficial regenerative processes. Brief stereotaxic insertion and removal of a micro-needle into the right hippocampus of 14 month old APP/PS1 mice brain resulted in a) stimulation of hippocampal neurogenesis and b) reduction of beta-amyloid plaque number in the CA-1 region. This treatment also resulted in a trend towards improved performance in the radial arm water maze (RAWM). Further studies of fundamental cellular mechanisms of the brain’s response to micro-injury will be useful for investigation of potential neuro-protective and deleterious effects of targeted micro-lesions and deep brain stimulation in Alzheimer Disease (AD).