Chronic increases in daily neuromuscular activity promote changes in gene expression in small and large dorsal root ganglion neurons in rat

Publication date: Available online 19 July 2018Source: NeuroscienceAuthor(s): Natasha Paddock, Patricia Sheppard, Phillip GardinerAbstractThe purpose of this study was to determine the response, in rat, to chronic physical activity in small and large DRG neurons. Rats were cage-confined or underwent 16-18 weeks of daily increased activity, via 2 hours of treadmill running per day or free access to voluntary exercise wheels, following which small (≤ 30µm) and large (≥ 40µm) diameter DRG neurons were harvested by laser capture microdissection from flash-frozen lumbar DRGs. Relative mRNA levels were determined using real-time polymerase chain reaction. Following chronic treadmill and voluntary wheel exercise, gene expression responses in neurons mostly differed between exercise types. Changes in both small and large DRG neurons included increases in opioid receptor mu subunit (MOR), NGF and GAP43, and decreases in 5HT1A, TrkA, TrkB, and delta type opioid receptor (DOR) mRNAs. In small DRG neurons, treadmill exercise increased the expression of mRNA for 5HT1D and decreased expression for 5HT1F receptors. In large DRG neurons, voluntary wheel exercise decreased the expression for 5HT1D receptors, whereas both treadmill and voluntary wheel exercise decreased the expression of mRNA for TrkC receptors. DRG neurons show slightly more changes in gene expression after voluntary exercise compared to the treadmill exercise group. Small and large lumbar sensory neurons are responsive...

Source: Neuroscience - July 20, 2018 Category: Neuroscience Source Type: research