Control of central synaptic specificity in insect sensory neurons.
Synaptic specificity is the culmination of several processes, beginning with the establishment of neuronal subtype identity, followed by navigation of the axon to the correct subdivision of neuropil, and finally, the cell-cell recognition of appropriate synaptic partners. In this review we summarize the work on sensory neurons in crickets, cockroaches, moths, and fruit flies that establishes some of the principles and molecular mechanisms involved in the control of synaptic specificity. The identity of a sensory neuron is controlled by combinatorial expression of transcription factors, the products of patterning and proneural genes. In the nervous system, sensory axon projections are anatomically segregated according to modality, stimulus quality, and cell-body position. A variety of cell-surface and intracellular signaling molecules are used to achieve this. Synaptic target recognition is also controlled by transcription factors such as Engrailed and may be, in part, mediated by cadherin-like molecules.
Blagburn
Jonathan M
JM
Institute of Neurobiology, Department of Physiology, Medical Sciences Campus, University of Puerto Rico, San Juan, Puerto Rico 00901-1123. jmblagbu@neurobio.upr.clu.edu
Bacon
Jonathan P
JP
D000818:Animals; D002490:Central Nervous System / Q000166:cytology / Q000196:embryology* / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D020439:Growth Cones / Q000502:physiology* / Q000648:ultrastructure; D007313:Insecta / Q000166:cytology / Q000196:embryology* / Q000502:physiology*; D009434:Neural Pathways / Q000166:cytology / Q000196:embryology / Q000254:growth & development; D009475:Neurons, Afferent / Q000166:cytology / Q000502:physiology*; D017956:Photoreceptor Cells, Invertebrate / Q000166:cytology / Q000254:growth & development; D015398:Signal Transduction / Q000235:genetics; D013569:Synapses / Q000502:physiology* / Q000648:ultrastructure