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Physiological properties of the mauthner system in the adult zebrafish
Author(s) -
Hatta Kohei,
Korn Henri
Publication year - 1998
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/(sici)1096-9861(19980615)395:4<493::aid-cne6>3.0.co;2-x
Subject(s) - mauthner cell , axon hillock , antidromic , neuroscience , electrophysiology , axon , zebrafish , postsynaptic potential , biophysics , excitatory postsynaptic potential , resting potential , synaptic potential , membrane potential , biology , inhibitory postsynaptic potential , time constant , local field potential , anatomy , fishery , fish <actinopterygii> , gene , biochemistry , receptor , electrical engineering , engineering
Abstract We investigated the morphological and electrophysiological properties of the Mauthner (M‐) cell and its networks in the adult zebrafish ( Danio rerio ) in comparison with those in the goldfish ( Carassius auratus ). The zebrafish M‐cell has an axon cap, a high resistivity structure which surrounds the initial segment of the M‐axon, and accounts for an unusual amplification of the fields generated within and around it. Second, extra‐ and intracellular recordings were performed with microelectrodes. The resting potential was ∼−80 mV with an input resistance of ∼0.42 MΩ. The M‐cell extracellular field was large (10‐20 mV), close to the axon hillock, and the latency of antidromic spikes short (∼0.4 milliseconds), confirming a high conduction velocity in the M‐axon. The extrinsic hyperpolarizing potential (EHP), which signals firing of presynaptic cells and collateral inhibition, was markedly lower at frequencies of spinal stimulation > ∼5/second, suggesting an organization of the recurrent collateral network similar to that in the goldfish. Inhibitory postsynaptic potentials (IPSPs) were highly voltage‐dependent; their decay time constant was increased by depolarizations. The presynaptic neurons which are numerous could be identified by their passive hyperpolarizing potential (PHP) produced by the M‐spike current. Auditory responses, mediated via mixed synapses (electrical and chemical), had short delays and hence are well suited to trigger the escape reaction. The similarities of their properties indicate that the wealth of information generated over decades in the goldfish can be extrapolated to the zebrafish. J. Comp. Neurol. 395:493–509, 1998. © 1998 Wiley‐Liss, Inc.