Keun-Yeong Jeong1, Ji-Hyuk Kang2. 1. Gachon Institute of Pharmaceutical Science, Gachon University, Incheon, Republic of Korea. 2. Department of Biomedical Laboratory Science, College of Natural Science, DaeJeon University, Daejeon, Republic of Korea.
Abstract
PURPOSE: 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). MATERIALS AND 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. CONCLUSION: 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.
PURPOSE: 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). MATERIALS AND METHODS:Itching was induced via neonatal capsaicin treatment in Sprague-Dawley rats (itchingrats), and scratching behavior of the control, itching, and gabapentin (GBP)-treated itchingrats was compared. Then the activated or deactivated brain regions were investigated in the control, itching, and GBP-treated itchingrats using a 4.7T MRI system. RESULTS: While the itchingrats engaged in vigorous scratching (121.2 ± 22.4 times), the scratching behavior was decreased in the GBP-treated itchingrats (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. CONCLUSION: 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: Di Yan; Andrew Blauvelt; Amit K Dey; Rachel S Golpanian; Samuel T Hwang; Nehal N Mehta; Bridget Myers; Zhen-Rui Shi; Gil Yosipovitch; Stacie Bell; Wilson Liao Journal: J Invest Dermatol Date: 2021-04-19 Impact factor: 7.590