Pink1-/- Rats Demonstrate Swallowing and Gastrointestinal Dysfunction in a Model of Prodromal Parkinson Disease

AbstractEarly motor and non-motor signs of Parkinson disease (PD) include dysphagia, gastrointestinal dysmotility, and constipation. However, because these often manifest prior to formal diagnosis, the study of PD-related swallow and GI dysfunction in early stages is difficult. To overcome this limitation, we used thePink1-/- rat, a well-established early-onset genetic rat model of PD to assay swallowing and GI motility deficits. Thirty male rats were tested at 4  months (Pink1-/- = 15, wildtype (WT) control = 15) and 6 months (Pink1-/- = 7, WT = 6) of age; analogous to early-stage PD in humans. Videofluoroscopy of rats ingesting a peanut-butter-barium mixture was used to measure mastication rate and oropharyngeal and pharyngoesophageal bolus speeds. Abnormal swallowing behaviors were also quantified. A second experiment t racked barium contents through the stomach, small intestine, caecum, and colon at hours 0–6 post-barium gavage. Number and weight of fecal emissions over 24 h were also collected. Compared to WTs,Pink1-/- rats showed slower mastication rates, slower pharyngoesophageal bolus speeds, and more abnormal swallowing behaviors.Pink1-/- rats demonstrated significantly delayed motility through the caecum and colon.Pink1-/- rats also had significantly lower fecal pellet count and higher fecal pellet weight after 24  h at 6 months of age. Results demonstrate that swallowing dysfunction occurs early inPink1-/- rats. Delayed transit to the colon a...
Source: Dysphagia - Category: Speech-Language Pathology Source Type: research