| Proposal
Detail |
| Grant: |
5R01NS028208-15
|
| Status: |
Public
|
| Service Type: |
Start to Finish Profiling
|
| IACUC: |
293-2001
|
| IACUC date: |
2001-11-12
|
| Study
Relevance: |
| Hypoxic-ischemic (HI) injury in the developing brain is a common cause of disability in children, and there are no effective treatments at this time. Exposure to sublethal hypoxic conditions (hypoxic preconditioning) 24 hours prior to hypoxic-ischemic insult is protective in the developing rat model. We have observed protective effects on brain histopathology and on long-term sensory-motor behavioral tasks. Changes in gene expression are thought to underlie this protective effect. By comparing gene expression in rats subjected to hypoxic preconditioning or sham conditioning at several time points from 0 to 24 hrs after preconditioning, we should gain insight into the mechanisms underlying these neuroprotective effects and may identify targets for therapeutic intervention. |
| Hypothesis: |
| We hypothesize that changes in gene expression underlie the protective effect of hypoxic preconditioning against subsequent hypoxic-ischemic insult. |
| Specific
Aim: |
| The aim of this study is to determine the effect of hypoxic preconditioning on global gene expression, and, in littermates, to examine the effect of hypoxic preconditioning 24 h prior to hypoxic-ischemic insult on brain histopathology. |
| Experimental
Procedure and Design: |
| Gene expression will be examined in two groups, 1) preconditioned and 2) sham controls, at 4 time points. On postnatal day 6, preconditioned animals are exposed to normothermic hypoxia for 3 hrs (8.0% oxygen, 36 degrees C), and sham animals are simultaneouosly exposed to normoxia at 36 degrees C. Animals are then returned to their dams until euthanized at 4 time points (0h, 2h, 8h, and 24h later). Five brains/group/timepoint will be used, with an equal number of males and females in each group. Brains are removed and dissected on ice. Cerebral cortex is dissected from both hemispheres and rapidly frozen on dry ice. Total RNA is isolated using the QIAGEN RNeasy Protect Maxi Kit. Littermates of these animals will be exposed to hypoxic preconditioning or sham preconditioning and subjected to hypoxic-ischemic injury 24 h later. These animals are euthanized at postnatal day 14 for histopathologic evaluation of injury. |
| Quality Control Description: |
| For each treatment group we will use 5 biological replicates at each time point. |
| Quality Control Types: |
|
biological_replicate
|
| Replicate Description: |
| For each treatment group we will use 5 biological replicates at each time point. Littermates will be assigned to the preconditioned or sham groups for each timepoint. Males and females will be balanced across treatment groups for each time point. |
| Replicate Types: |
|
biological_replicate
|
| Experimental Factors: |
|
Conditions that are tested in the experiment. At least one is required. Experimental factors are the independent variables in the experiment.
|
|
|
Factor Name
|
Description
|
Factor Category
|
|
hypoxic preconditioning
|
exposure to hypoxic conditions (8% ox...
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atmosphere
|
|
Time
|
Samples collected at multiple time po...
|
timepoint
|
|
|
