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From synapses to behavior: Development of a sensory‐motor circuit in the leech
Author(s) -
MarinBurgin Antonia,
Kristan William B.,
French Kathleen A.
Publication year - 2008
Publication title -
developmental neurobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.716
H-Index - 129
eISSN - 1932-846X
pISSN - 1932-8451
DOI - 10.1002/dneu.20551
Subject(s) - neuroscience , leech , biology , electrical synapses , biological neural network , sensory system , neuronal circuits , nerve net , inhibitory postsynaptic potential , electrophysiology , process (computing) , electronic circuit , computer science , gap junction , physics , microbiology and biotechnology , world wide web , intracellular , operating system , quantum mechanics
The development of neuronal circuits has been advanced greatly by the use of imaging techniques that reveal the activity of neurons during the period when they are constructing synapses and forming circuits. This review focuses on experiments performed in leech embryos to characterize the development of a neuronal circuit that produces a simple segmental behavior called “local bending.” The experiments combined electrophysiology, anatomy, and FRET‐based voltage‐sensitive dyes (VSDs). The VSDs offered two major advantages in these experiments: they allowed us to record simultaneously the activity of many neurons, and unlike other imaging techniques, they revealed inhibition as well as excitation. The results indicated that connections within the circuit are formed in a predictable sequence: initially neurons in the circuit are connected by electrical synapses, forming a network that itself generates an embryonic behavior and prefigures the adult circuit; later chemical synapses, including inhibitory connections, appear, “sculpting” the circuit to generate a different, mature behavior. In this developmental process, some of the electrical connections are completely replaced by chemical synapses, others are maintained into adulthood, and still others persist and share their targets with chemical synaptic connections. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008