Chronic Capsaicin Does Not Induce Microglia Response in Adult Rat

Advisor Information

Suzanne Sollars

Location

Dr. C.C. and Mabel L. Criss Library

Presentation Type

Poster

Start Date

3-3-2017 10:45 AM

End Date

3-3-2017 12:00 PM

Abstract

Capsaicin is the neurotoxin that makes chili peppers spicy and has been shown to cause changes to the taste system following chronic consumption. Microglia are immune cells in the brain that activate and multiply in response to infection or injury. After taste nerve injury, microglia numbers increase in a region of the brainstem called the nucleus of the solitary tract (NTS). The current study tested whether 7 consecutive days of low dose capsaicin consumption was sufficient to impact microglia density in the NTS of adult rats. Capsaicin was presented at a 5 ppm (16.5 μM) concentration mixed in 2.5% ethanol (used to dissolve the capsaicin) and 30% sucrose (to encourage consumption). Control animals were adult rats similar in age that received no treatment. Microglia density in the NTS was assessed two days after treatment concluded. Microglia were visualized with an antibody against Iba1 (a marker for microglia) and quantified using a microscope and Neurolucida (MBF Bioscience) software. Microglia density was found for each animal by dividing the number of microglia per animal by the total area of interest. No differences in microglia density were observed between conditions, suggesting that peripheral exposure to low dose capsaicin does not induce a central immune response. This study is one of the first to quantify microglia response following peripheral exposure to a neurotoxin commonly consumed worldwide by both humans and animals.

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COinS
 
Mar 3rd, 10:45 AM Mar 3rd, 12:00 PM

Chronic Capsaicin Does Not Induce Microglia Response in Adult Rat

Dr. C.C. and Mabel L. Criss Library

Capsaicin is the neurotoxin that makes chili peppers spicy and has been shown to cause changes to the taste system following chronic consumption. Microglia are immune cells in the brain that activate and multiply in response to infection or injury. After taste nerve injury, microglia numbers increase in a region of the brainstem called the nucleus of the solitary tract (NTS). The current study tested whether 7 consecutive days of low dose capsaicin consumption was sufficient to impact microglia density in the NTS of adult rats. Capsaicin was presented at a 5 ppm (16.5 μM) concentration mixed in 2.5% ethanol (used to dissolve the capsaicin) and 30% sucrose (to encourage consumption). Control animals were adult rats similar in age that received no treatment. Microglia density in the NTS was assessed two days after treatment concluded. Microglia were visualized with an antibody against Iba1 (a marker for microglia) and quantified using a microscope and Neurolucida (MBF Bioscience) software. Microglia density was found for each animal by dividing the number of microglia per animal by the total area of interest. No differences in microglia density were observed between conditions, suggesting that peripheral exposure to low dose capsaicin does not induce a central immune response. This study is one of the first to quantify microglia response following peripheral exposure to a neurotoxin commonly consumed worldwide by both humans and animals.