I am interested in the mechanisms that underlie synaptic competition between neurons that innervate the same target cell. Such competitive interactions are responsible for sharpening the patterns of neural connections during development and may also be important in learning and memory formation. My laboratory studies synaptic competition by visualizing synaptic rearrangements directly in living animals using modern optical imaging techniques. We have concentrated on neuromuscular junctions in a very accessible neck muscle in mice where new transgenic animals and other labeling strategies allow individual nerve terminals and postsynaptic specializations to be monitored over hours or months. In addition, we have developed several new methods to improve our ability to resolve synaptic structure.
Bishop DL, Misgeld T, Walsh MK, Gan WB, Lichtman JW. Axon Branch Removal at Developing Synapses by Axosome Shedding. Neuron. 2004 44:651-661. [Figures and Movies]
Kasthuri N, Lichtman JW. The role of neuronal identity in synaptic competition. Nature. 2003 424:426-30.
Buffelli M, Burgess RW, Feng G, Lobe CG, Lichtman JW, Sanes JR.Genetic evidence that relative synaptic efficacy biases the outcome of synaptic competition. Nature. 2003 424:430-4.
Walsh MK, Lichtman JW. In vivo time-lapse imaging of synaptic takeover associated with naturally occurring synapse elimination. Neuron. 2003 37:67-73.
Akaaboune M, Culican SM, Turney SG, Lichtman JW. Rapid and reversible effects of activity on acetylcholine receptor density at the neuromuscular junction in vivo. Science. 1999 286:503-7.
Gan WB, Lichtman JW. Synaptic segregation at the developing neuromuscular junction. Science. 1998 282:1508-11.
Nguyen QT, Parsadanian AS, Snider WD, Lichtman JW. Hyperinnervation of neuromuscular junctions caused by GDNF overexpression in muscle. Science. 1998 279:1725-9.
Colman H, Nabekura J, Lichtman JW. Alterations in synaptic strength preceding axon withdrawal. Science. 1997 275:356-61.
Balice-Gordon RJ, Lichtman JW. Long-term synapse loss induced by focal blockade of postsynaptic receptors. Nature.1994 372:519-24.