Abstract
Penetration of a microneedle and injection of 4 μl. saline into the neocortex of the 5 day old rat brain produced no changes in behaviour of the rats up to 21 days post-injection. Within 24 hours sections indicated that tissue damage was apparent only at the pia-arachnoid membrane and where fluid was released; elsewhere the needle pathway was identified by the enzyme response. The enzyme histochemistry showed a marked increase in glial cell activity of some phosphatases within 24 hours at the site of injury; the pia-arachnoid and outer limiting membrane also showed abnormally high phosphatase reactions. NADH(2)-diaphorase was the only dehydrogenase that was raised in some nerve and glial cells at 24 hours post-injection but other dehydrogenases, mainly LDH and SDH, showed changes at four days post-injection. The phosphatases and 5'-nucleotidase previously showing intense glial cell enzyme reactions appeared to reach peaks of activity at eight days, and at 16 days the onset of scarring was apparent. In the pia-arachnoid enzyme activity increased to 21 days. Some enzymes, particularly AChE and MAO, showed no alterations of note throughout.
MeSH terms
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Acetylcholinesterase / metabolism*
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Acid Phosphatase / metabolism
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Adenosine Triphosphatases / metabolism
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Animals
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Animals, Newborn
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Arachnoid / enzymology
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Brain Injuries / enzymology*
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Cerebral Cortex / drug effects
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Cerebral Cortex / enzymology
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Dihydrolipoamide Dehydrogenase / metabolism
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Glucosephosphate Dehydrogenase / metabolism
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Glycerolphosphate Dehydrogenase / metabolism
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L-Lactate Dehydrogenase / metabolism
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Magnesium / metabolism
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Monoamine Oxidase / metabolism
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NADH, NADPH Oxidoreductases / metabolism
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Nucleotidases / metabolism
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Oxidoreductases / metabolism*
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Phosphoric Monoester Hydrolases / metabolism*
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Pia Mater / enzymology
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Pyrophosphatases / metabolism
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Rats
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Sodium Chloride / pharmacology
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Succinate Dehydrogenase / metabolism
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Thiamine / metabolism
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Time Factors
Substances
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Sodium Chloride
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Oxidoreductases
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Glycerolphosphate Dehydrogenase
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L-Lactate Dehydrogenase
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Glucosephosphate Dehydrogenase
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Succinate Dehydrogenase
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Monoamine Oxidase
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NADH, NADPH Oxidoreductases
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Dihydrolipoamide Dehydrogenase
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Acetylcholinesterase
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Nucleotidases
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Acid Phosphatase
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Phosphoric Monoester Hydrolases
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Adenosine Triphosphatases
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Pyrophosphatases
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Magnesium
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Thiamine