scholarly journals Detection of transient synchrony across oscillating receptors by the central electrosensory system of mormyrid fish

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Alejandro Vélez ◽  
Bruce A Carlson
Keyword(s):  
Electric Fish ◽  
Frequency Tuning ◽  
Weakly Electric Fish ◽  
Sensory Coding ◽  
Electrosensory System ◽  
Mormyrid Fish ◽  
Intrinsic Oscillation ◽  
Oscillation Frequencies ◽  
Weakly Electric ◽  
Peripheral Sensory

Recently, we reported evidence for a novel mechanism of peripheral sensory coding based on oscillatory synchrony. Spontaneously oscillating electroreceptors in weakly electric fish (Mormyridae) respond to electrosensory stimuli with a phase reset that results in transient synchrony across the receptor population (<xref ref-type="bibr" rid="bib5">Baker et al., 2015</xref>). Here, we asked whether the central electrosensory system actually detects the occurrence of synchronous oscillations among receptors. We found that electrosensory stimulation elicited evoked potentials in the midbrain exterolateral nucleus at a short latency following receptor synchronization. Frequency tuning in the midbrain resembled peripheral frequency tuning, which matches the intrinsic oscillation frequencies of the receptors. These frequencies are lower than those in individual conspecific signals, and instead match those found in collective signals produced by groups of conspecifics. Our results provide further support for a novel mechanism for sensory coding based on the detection of oscillatory synchrony among peripheral receptors.

Neuronal mechanisms for object discrimination in the weakly electric fish Eigenmannia virescens

1977 ◽  
Vol 66 (1) ◽  
pp. 141-158
Author(s):  
A. S. Feng ◽  
T. H. Bullock
Keyword(s):  
Electric Fish ◽  
Electrical Stimulus ◽  
Weakly Electric Fish ◽  
Object Discrimination ◽  
Lateral Line Nerve ◽  
Response Differentiation ◽  
Neuronal Mechanisms ◽  
Eigenmannia Virescens ◽  
Weakly Electric ◽  
Peripheral Sensory

The peripheral sensory basis for object discrimination was investigated in the weakly electric fish Eigenmannia virescens. Single unit recordings were made from the primary afferent fibres in the posterior branch of the anterior lateral line nerve while the local electric field (self-generated and stimulated) was modified by external resistance and capacitance shunts. Both fibre types (probability and phase coders) responded differentially to capacitance and resistance shunts of equivalent impedence. The degree of response differentiation between the two shunting conditions varied with the intensity of the electrical stimulus at the receptor. These data suggest that the primary electroreceptors can discriminatively encode the two electrical characteristics of ‘objects’. However, since the response of primary electroreceptors also varied with the spatial orientation of the shunting electrodes, central structures must play an important role in object discrimination.

A neural model of electrosensory system making electrolocation of weakly electric fish

2001 ◽  
Vol 38-40 ◽  
pp. 1349-1357 ◽  
Author(s):  
Yoshiki Kashimori ◽  
Masanori Minagawa ◽  
Satoru Inoue ◽  
Osamu Hoshino ◽  
Takeshi Kambara
Keyword(s):  
Electric Fish ◽  
Neural Model ◽  
Weakly Electric Fish ◽  
Electrosensory System ◽  
Weakly Electric

scholarly journals Count and spark? The echo response of the weakly electric fish Gnathonemus petersii to series of pulses

2001 ◽  
Vol 204 (8) ◽  
pp. 1401-1412
Author(s):  
S. Schuster
Keyword(s):  
Electric Fish ◽  
Electric Organ ◽  
Weakly Electric Fish ◽  
Simple Strategy ◽  
Mormyrid Fish ◽  
Pulse Type ◽  
After Effect ◽  
Electric Organ Discharges ◽  
Weakly Electric ◽  
Gnathonemus Petersii

Weakly electric fish of the pulse type electrolocate objects in the dark by emitting discrete electric organ discharges (EODs) separated by intervals of silence. Two neighbouring pulse-type fish often reduce the risk of discharging simultaneously by means of an ‘echo response’: one fish will respond to a neighbour's EOD with a discharge of its own following at a fixed short latency so that its EOD will occur long before the next EOD of its neighbour. Although working elegantly for two partners, this simple strategy should fail in larger groups because two fish could discharge in response to the same EOD of a third fish. Here, I show that the mormyrid fish Gnathonemus petersii could use a simple mechanism to reduce this problem. Individuals were stimulated with two closely spaced pulses, the second following so as to coincide with an echo given in response to the first. All the fish examined were able to respond more to the second pulse so that most of their echoes did not collide with the second pulse. An analysis was made of how echoing more to the second pulse depends on (i) the delay at which the stimulus followed the last spontaneous EOD, (ii) the spontaneous firing rate, (iii) the intensity of the stimulus, (iv) the number of stimulus pulses, (v) the interval between stimulus pulses, and (vi) the level of previous stimulation with double pulses. The results suggest that echoing more in response to the second pulse is probably because the first pulse causes an after-effect whose inferred properties would be compatible with the properties of the mormyromast afferences thought to be involved in the echo response.

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