title: Investigation of the pruritus-induced functional activity in the rat brain using manganese-enhanced MRI.
abstract: OBJECTIVE
  To provide clear information on the activation regions of itching, we investigated the functional activity of cerebral regions in the pruritus-induced rat model using manganese-enhanced magnetic resonance imaging (MEMRI).
  
  
  METHODS
  Itching was induced via neonatal capsaicin treatment in Sprague-Dawley rats (itching rats), and scratching behavior of the control, itching, and gabapentin (GBP)-treated itching rats was compared. Then the activated or deactivated brain regions were investigated in the control, itching, and GBP-treated itching rats using a 4.7T MRI system.
  
  
  RESULTS
  While the itching rats engaged in vigorous scratching (121.2 ± 22.4 times), the scratching behavior was decreased in the GBP-treated itching rats (30.6 ± 8.8 times). GBP induced the attenuation of functional activity in two regions -7.10 mm from bregma, in one region -6.65 mm from bregma, and in one region -6.06 mm from bregma. The brain regions related to itching were as follows: parafascicular nucleus, thalamus, superior/inferior colliculus, periaqueductal gray, cingulate cortex, amygdala, midbrain regions, lateral habenula, and hypothalamic areas.
  
  
  CONCLUSIONS
  Our MEMRI investigation indicates new functional activity of cerebral regions in rats due to the effect of itching or GBP. This information could be used to monitor the therapeutic effects of novel agents or for clinical strategies to treat pathological itch.
authors.affiliation: Gachon Institute of Pharmaceutical Science, Gachon University, Incheon, Republic of Korea.
authors.forename: Keun-Yeong
authors.initials: KY
authors.lastname: Jeong
authors.affiliation: Department of Biomedical Laboratory Science, College of Natural Science, DaeJeon University, Daejeon, Republic of Korea.
authors.forename: Ji-Hyuk
authors.initials: JH
authors.lastname: Kang
mesh_terms: D000588:Amines / Q000737:chemistry; D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping; D002211:Capsaicin; D003287:Contrast Media / Q000737:chemistry*; D003509:Cyclohexanecarboxylic Acids / Q000737:chemistry; D000077206:Gabapentin; D006179:Gyrus Cinguli / Q000473:pathology; D008032:Limbic System / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008345:Manganese / Q000737:chemistry*; D011537:Pruritus / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013788:Thalamus / Q000473:pathology; D005680:gamma-Aminobutyric Acid / Q000737:chemistry
chemical_list: D000588:Amines; D003287:Contrast Media; D003509:Cyclohexanecarboxylic Acids; D008345:Manganese; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin; D002211:Capsaicin
keywords: brain; functional activity; gabapentin (GBP); manganese-enhanced MRI (MEMRI); pruritus; rat