Chemoattraction of sensory neuron growth cones by diffusible concentration gradients of acetylcholine.
Axon guidance cues are critical for the development and repair of both the central and peripheral nervous systems. These cues serve to help select the pathways taken by axon growth cones, by attracting or repulsing them. During development and following injury to the adult peripheral nervous system, neurons must extend processes, often over long distances, through a variety of cellular environments composed of innervated and uninnervated cells, to find, recognize, and synapse on their appropriate targets. The responsibility for recognizing and responding to the extensive number of cues that are encountered as axons elongate falls on the growth cones at the tip of the elongating axons. Cajal (1928) proposed that denervated target cells release diffusible factors that assist in orienting the direction of out-growth of peripheral axons. However, it is only relatively recently that experiments to identify the molecules responsible for serving this function, and the molecular mechanisms by which they function, have begun to bear fruit. Gradients of both substrate-bound and diffusible factors have now been shown to play critical roles in directing axon outgrowth. The present experiments were aimed at determining whether the neurotransmitter acetylcholine (ACh) can act as a chemoattractant for adult sensory neuron growth cones.
Kuffler
D P
DP
Institute of Neurobiology, University of Puerto Rico, San Juan 00901, USA.
D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D001369:Axons / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D002633:Chemotaxis; D005727:Ganglia, Spinal / Q000166:cytology / Q000502:physiology*; D018715:Microscopy, Video; D009475:Neurons, Afferent / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D011894:Rana pipiens
D000109:Acetylcholine