The researchers then offered the rats chocolate milk in their cages, but mixed it with lithium chloride, which causes light nausea.

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Symptoms typically develop within three to seven days of exposure and can include stiff neck, fever, headache, nausea, vomiting, increased sensitivity to light and an altered mental state, often confusion.

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Potential signs and symptoms of a concussion include headache, dizziness, nausea, ear ringing, sensitivity to light and sounds, slurred speech, impaired memory or judgment, as well as changes in reaction time or balance.

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