Transcriptional Changes in Rat Dorsal Root Ganglia Neurons During Stretch-Mediated Axon Growth

The development of meter-long axons within the nervous system is a remarkable, yet unresolved biological process. The most widely studied aspects of neuronal growth focus on the extension and chemotropism of growth cones. However, over the course of organismal development, short axons elongate up to one meter in length with the systemic expansion of mitotic tissues. The preeminent regulatory mechanism for such synchronized growth between the nervous system and the tissues it spans, is the biomechanical stretch of axons, a known stimulus of axon growth. Here, we reveal the transcriptional profile of stretch-mediated axon growth as found using embryonic rat dorsal root ganglia neurons stretch-grown in vitro. Computer-controlled bioreactors were used to maintain a persistent state of 25 % axon strain for one week to maximize mechanotransduced signaling changes in vitro. Genome-wide DNA microarray analysis was performed on the corresponding somata of contiguous high density axons that spanned 1.7 cm in length. Non-stretch grown sham cultures were established from the same biological samples as stretch-grown cultures, which were used to calculate fold-changes relative to stretch-grown cultures.