Tensile regulation of axonal elongation and initiation

摘要: Neurites of chick sensory neurons in culture were attached by their growth cones to glass needles known compliance and subjected increasing tensions as steps constant force; each step lasted 30–60 min was 25–50 mu dyn greater than the previous step. After correcting for elastic stretching, neurite elongation rate increased proportion tension magnitude a threshold. The value threshold required varied between 25 560 dyn, with most 50 150 dyn. sensitivity neurites surprisingly high: an increase 1 average about 1.5 microns/hr. linear relationship provides simple control mechanism axons accommodate tissue expansion growing animals that consistently maintains moderate rest on axons. Styrene microspheres treated polyethyleneimine used label surface order determine site pattern addition during experimental “towed growth” regime. New membrane is added interstitially throughout neurite, but different regions vary widely amount new added. This contrasts specifically at distal end growth-cone- mediated growth. sites towing cone indicate process sensitive mode We confirmed finding Bray (1984) can be initiated de novo application cell margin neurons.(ABSTRACT TRUNCATED AT 250 WORDS)