Cerebral and cerebellar volumes on MRI at p18 and p30.

<p><b>A)</b> Residual cerebral volumes at p18 are lower in NT compared to controls (* p<0.001) and to TH (# p<0.001). By p30, both NT and TH cerebral volumes are less than controls (* p = 0.003 and ^ p<0.001). <b>B)</b> Residual cerebral volumes stratified by sex. Male mouse residual cerebral volume at p18 was smaller in NT vs. TH and controls (*p<0.001 and # p = 0.002). At p30, differences persisted in males between NT and controls (*p<0.001). No differences were found between female groups. <b>C)</b> Cerebellar volumes stratified by sex. At p18, cerebellar volume in TH males was smaller than controls (*p = 0.01). No differences between groups were found in female cerebellar volume. p18 males: control n = 6, NT n = 9, TH n = 12; females: control n = 6, NT n = 11, TH n = 10. p30 males: control n = 7, NT n = 9, TH n = 12; females: control n = 5, NT n = 11, TH n = 11.</p

Neuropathology in HI mice at p18.

<p><b>A)</b> Severe injury in cerebral cortex with focal cystic lesion at a mid-striatal level. <b>B)</b> Milder cortical injury (compared to A), a focal gliotic scar marking an area of neuronal loss. <b>C)</b> Severe hippocampal injury but with preservation of overall architecture of hippocampus. Pyramidal neuron elimination is prominent and remnants of the granule cell layers in dentate gyrus remain. The hippocampus is infiltrated with small cells. <b>D)</b> Mild hippocampal injury observed as small foci of pyramidal neuron loss (arrow). <b>E)</b> Fluorojade positive neuritic processes within the ipsilateral cortical neuropil. <b>F)</b> Fluorojade positive processes near the hippocampal alveus. <b>G)</b> Fluorojade positive cells and processes within the pyramidal layer of the contralateral hippocampus and the overlying corpus callosum. <b>H)</b> Fluorojade positive cells in the ipsilateral amygdala. <b>I&J)</b> Neurofilament immunostaining of the contralateral cerebral peduncle (I), containing corticospinal tract axons, and the ipsilateral cerebral peduncle (J) showing a loss of axonal neurofilament immunoreactivity. Ipsilateral cortex was severely injured. Asterisks identify columns of the fornix for orientation. <b>K)</b> Swollen astrocytes in cortex adjacent to area of injury on H&E. <b>L)</b> Signs of ongoing inflammatory response on H&E staining with vascular cuffing and activated astrocytes.</p

GFAP immunohistochemistry at p18.

<p>Cortex and white matter injury showing GFAP positive areas and paucity of stain in control. Hippocampal injury with glial staining and lack of staining in control mouse. Striatal injury with widespread GFAP staining indicating glial activation and lack of staining in control, other than normal white matter staining.</p

Representative MRI and gross histopathology at p18 and p30.

<p><b>A)</b> Representative T2—weighted MR imaging animals at each time point, treatment, and sex. Images at p18 and p30 are from the same animal. The trend of mild to moderate, variable injury and neuroprotection particularly in females is demonstrated. <b>B)</b> Low power views H&E stained anterior and posterior sections from p30 male mice.</p

Regional volumes (cortex, hippocampus, striatum, and thalamus) on MRI ipsilateral to carotid ligation at p18 and p30.

<p><b>A&B)</b> The cortex and hippocampus are smaller in NT compared to TH males (# p<0.001). Regional volumes were not different between female groups. NT males continue to have smaller volumes in the cortex compared to controls (* p = 0.042). At p30, the hippocampal volumes in NT males are smaller than both control and TH males but the TH group also has smaller hippocampus volume compared to control (*p <0.001 (NT), p = 0.002 (TH), # p = 0.041). <b>C)</b> NT males had smaller striatal volumes than controls at p18 (*p = 0.019). The striatum volume at p30 was smaller in TH females when compared to controls (*p = 0.034). <b>D)</b> The thalamus at p18 is smaller in male NT mice (vs. control p = 0.043), there were no differences between groups at p30.</p

Repeated measures of cerebral and cerebellar volume analyzed by total percentage of growth from p18 to p30.

<p><b>A)</b> There were no significant differences in cerebral growth amongst groups. <b>B)</b> Cerebellar growth in male mice was not different between treatment groups. Female TH treated mice had significantly increased cerebellar growth when compared to control female mice (*p = 0.048). Controls n = 4 males and females, NT n = 4 males and females, TH n = 6 males and 5 females.</p

Behavioral testing.

<p><b>A)</b> Negative geotaxis task and forelimb task times at p14 were similar amongst treatment groups in both sexes. NT female mice performed open field test slower than control females (#p = 0.04). Males: control n = 14, NT n = 10, TH n = 11, females: control n = 15, NT n = 10, TH n = 10. <b>B)</b> Y-Maze testing at p21 (Phase 1): NT males scored lower than controls (*p = 0.02) and both NT and TH females scored lower than controls (# p = 0.01 and ^ p = 0.002, respectively). <b>C)</b> Y-maze Phase 2 (p28). Both NT and TH mice entered blocked arm fewer times than controls (*p<0.001 and #p = 0.001, respectively). <b>D)</b> Y-Maze Phase 2, stratified by sex. NT and TH females entered into blocked arm fewer times than control females (*p = 0.02 and # p = 0.01, respectively). NT males entered blocked arm blocked arm fewer times than controls (* p = 0.02). Males: control n = 12, NT n = 11, TH n = 12, Females: control n = 11, NT n = 10, TH n = 11.</p

Additional file 2: Table S2. of A pilot cohort study of cerebral autoregulation and 2-year neurodevelopmental outcomes in neonates with hypoxic-ischemic encephalopathy who received therapeutic hypothermia

Blood pressure in relation to the optimal mean arterial blood pressure and the Mullen score. (DOC 49 kb