Disruptions in laminar structure of mouse brain cortex after hypoxic ischemia injury.

<p><i>A</i>: (<i>left</i>) Histological tissue sections show the laminar structure of the cortex in the normothermia group. Scale bar, 500 µm. The designated areas are enlarged in the bottom panels for clarity. Scale bar, 200 µm; <i>(right</i>) average areas of superficial and deep cortical layers measured on mouse brain sections (n = 6, mean±SE). *<i>P</i><0.05 (Wilcoxon test). <i>B:</i> Laminar structure in the hypothermia group (n = 6, mean±SE). Other notations defined in (<i>A</i>).</p

Neuronal cell density reduced in adult mouse brains after hypoxic ischemia injury.

<p><i>A</i>: Immunohistochemistry shows NeuN-positive cells in the cortex (<i>Top</i>) and striatum (<i>Bottom</i>) of mice subjected to hypoxic ischemia injury, followed by normothermia. Scale, 500 µm. Average density of NeuN cells (n = 11 mouse brains, mean±SE) was assessed in the contralateral (black) and ischemic ipsilateral (white) hemispheres. <i>B</i>: High magnification images of the cortices of mice in normothermia and hypothermia groups. Scale, 200 µm. *<i>P<</i>0.05 (Wilcoxon test). Other notations are defined in (<i>A</i>).</p

Apoptosis (TUNEL staining) in the cortex 24 h after hypoxic ischemia injury.

<p><i>A</i>: Tissue sections are shown from brain hemispheres subjected to mild ischemic injury (<i>top</i>) or severe ischemic injury in mice from the normothermia (<i>middle</i>) and hypothermia (<i>bottom</i>) groups. <i>Arrow</i> indicates TUNEL-positive cells. Scale, 500 µm. <i>B</i>: <i>(left</i>) Average number of TUNEL-positive cells (mean±SE) in the superficial and deep cortical layers in the normothermia (n = 9) and hypothermia (n = 8) groups. *<i>P</i><0.05 (Wilcoxon test). <i>(Right</i>) Distribution of the number of TUNEL-positive cells in the superficial layers and deep cortical layers.</p

Examination of hypoxic ischemia injury in predevelopmental mouse brain.

<p><i>A</i>: Cerebral blood flow immediately after carotid artery ligation in a P2–P3 mouse. <i>B</i>: Experimental paradigm. Hypoxic injury was followed by 24 h of normothermia or hypothermia, and mice were sacrificed at the indicated time points (P4, 5 weeks). Note that behavioral tests were conducted at 4 weeks of age. <i>C, D</i>: Representative examples of hematoxylin staining for normothermia (C) or hypothermia (D) treated mice. In the normothermia group, the boundary was obscure between the superficial layers and the deep layers (white asterisk). Scale, 500 µm. High magnification images of the contralateral (<i>left</i>) and ipsilateral (<i>right</i>) hemisphere. Scale, 200 µm.</p