In the study, it was found that increasing the number of hypocretin-producing neurons in the mice with opioids resulted in the elevation of hypocretin levels in the locus coeruleus, an area of the brain known to play a role in regulating opioid withdrawal symptoms.
UCLA researchers also found that the increased amounts of hypocretin present in the locus coeruleus were directly involved in increasing the levels of an enzyme called tyrosine hydroxylase, which is responsible for making norepinephrine, a naturally occurring neurochemical in the body.
The researchers developed a hypothesis that the removal of the hypocretin-producing neurons would lessen the signs of withdrawal in the mice. Their findings confirmed the hypothesis.
The study appears in the Jan. 12 edition of the Journal of Neuroscience.