Interactions with epidermal cells could likewise be important. For example, in tumor cells, integrin engagement is thought to counterbalance adherens junction-based compaction forces between cells to prevent cell invasion (Overholtzer et al., 2007). In cells that are detached from the

matrix, adhesive contacts are predicted to shift to predominantly cell-cell adhesion with imbalanced compaction forces pushing one cell into another (Overholtzer et al., 2007). Although the precise mechanism for how enclosure of da neuron dendrites arises is presently Regorafenib nmr unknown, it will be interesting to examine whether, on a local scale of dendrite segments, balanced adhesion may play a role. The physiological consequences of placement of dendrites in proximity to the ECM or in enclosures are unknown. The ECM might influence the transduction of mechanical forces to the neuronal cytoskeleton and impact mechanosensation (Du et al., 1996 and Emtage et al., 2004), and studies in C. elegans suggest roles for integrin signaling in touch sensitivity ( Calixto et al., 2010). In the da neuron system, class IV neurons are thought to sense

noxious mechanical, thermal, or photic stimuli, whereas class I neurons appear to function as proprioceptors ( Hughes LY294002 molecular weight and Thomas, 2007, Hwang et al., 2007, Song et al., 2007 and Xiang et al., 2010). Mechanosensation could be affected by the specific relationship between sensory arbors and surrounding tissues. For example, mechanical stimuli or compression impinging on the body wall could distort surface versus enclosed dendrites

in different ways ( Osborne, 1964). Intermittent Fossariinae enclosure could also result in spaced tetherings of dendrites, which could conceivably establish local foci for mechanosensation across an arbor ( Hall and Treinin, 2011). Finally, it is worth noting that among the different sensory neuron types, enclosure was observed predominantly along neurons with more highly arborized dendrites. One speculative possibility is that this arrangement could isolate dendritic membrane and conceivably impact signal transduction along more expansive arbors. Behavioral analyses should begin to address these and other possible functional consequences of the relationship between da neuron sensory dendrites and their substrate. Integrin-deficient class I neurons showed reduced dendritic length and branching complexity and also acquired markers of dendritic enclosure, including Coracle immunoreactivity and intermittent protection from surface anti-HRP labeling. How are these phenotypes related? Fly sensory neurons show ongoing growth of dendrites during larval development so that territory coverage scales with overall expansion of the body wall (Parrish et al., 2009 and Sugimura et al., 2003).