TY - JOUR
T1 - Electrical synaptic transmission in developing zebrafish
T2 - Properties and molecular composition of gap junctions at a central auditory synapse
AU - Yao, Cong
AU - Vanderpool, Kimberly G.
AU - Delfiner, Matthew
AU - Eddy, Vanessa
AU - Lucaci, Lexander G.
AU - Soto-Riveros, Carolina
AU - Yasumura, Thomas
AU - Rash, John E.
AU - Pereda, Alberto E.
N1 - Publisher Copyright:
© 2014, J Neurophysiol. All rights reserved.
PY - 2014/11/1
Y1 - 2014/11/1
N2 - In contrast to the knowledge of chemical synapses, little is known regarding the properties of gap junctionmediated electrical synapses in developing zebrafish, which provide a valuable model to study neural function at the systems level. Identifiable “mixed” (electrical and chemical) auditory synaptic contacts known as “club endings” on Mauthner cells (2 large reticulospinal neurons involved in tail-flip escape responses) allow exploration of electrical transmission in fish. Here, we show that paralleling the development of auditory responses, electrical synapses at these contacts become anatomically identifiable at day 3 postfertilization, reaching a number of∼6 between days 4 and 9. Furthermore, each terminal contains ∼18 gap junctions, representing between 2,000 and 3,000 connexon channels formed by the teleost homologs of mammalian connexin 36. Electrophysiological recordings revealed that gap junctions at each of these contacts are functional and that synaptic transmission has properties that are comparable with those of adult fish. Thus a surprisingly small number of mixed synapses are responsible for the acquisition of auditory responses by the Mauthner cells, and these are likely sufficient to support escape behaviors at early developmental stages.
AB - In contrast to the knowledge of chemical synapses, little is known regarding the properties of gap junctionmediated electrical synapses in developing zebrafish, which provide a valuable model to study neural function at the systems level. Identifiable “mixed” (electrical and chemical) auditory synaptic contacts known as “club endings” on Mauthner cells (2 large reticulospinal neurons involved in tail-flip escape responses) allow exploration of electrical transmission in fish. Here, we show that paralleling the development of auditory responses, electrical synapses at these contacts become anatomically identifiable at day 3 postfertilization, reaching a number of∼6 between days 4 and 9. Furthermore, each terminal contains ∼18 gap junctions, representing between 2,000 and 3,000 connexon channels formed by the teleost homologs of mammalian connexin 36. Electrophysiological recordings revealed that gap junctions at each of these contacts are functional and that synaptic transmission has properties that are comparable with those of adult fish. Thus a surprisingly small number of mixed synapses are responsible for the acquisition of auditory responses by the Mauthner cells, and these are likely sufficient to support escape behaviors at early developmental stages.
KW - Auditory development
KW - Connexin 35
KW - Connexin 36
KW - Escape response
KW - Mauthner cell
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U2 - 10.1152/jn.00397.2014
DO - 10.1152/jn.00397.2014
M3 - Article
C2 - 25080573
AN - SCOPUS:84908406613
SN - 0022-3077
VL - 112
SP - 2102
EP - 2113
JO - Journal of neurophysiology
JF - Journal of neurophysiology
IS - 9
ER -