Neural correlates of novelty detection in pulse-type weakly electric fish

1986 ◽  
Vol 159 (2) ◽  
pp. 191-200 ◽  
Author(s):  
Harold J. Grau ◽  
Joseph Bastian
Keyword(s):  
Electric Fish ◽  
Novelty Detection ◽  
Neural Correlates ◽  
Weakly Electric Fish ◽  
Pulse Type ◽  
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.

scholarly journals Tethered unitary recordings suggest a spike-timing electrosensory code in the electrosensory lobe of Gymnotus omarorum

2020 ◽  
Vol 1 ◽  
Author(s):  
Alejo Rodríguez-Cattáneo ◽  
Ana-Carolina Pereira ◽  
Pedro A. Aguilera ◽  
Ángel A. Caputi
Keyword(s):  
Electric Fish ◽  
Electric Organ Discharge ◽  
Electric Organ ◽  
Spike Timing ◽  
Weakly Electric Fish ◽  
Wave Type ◽  
Timing Pattern ◽  
Pulse Type ◽  
Weakly Electric ◽  
The Brain

AbstractEvaluation of neural activity during natural behaviours is essential for understanding how the brain works. Here we show that neuron-specific self-evoked firing patterns are modulated by an object’s presence, at the electrosensory lobe neurons of tethered-moving Gymnotus omarorum. This novel preparation shows that electrosensory signals in these pulse-type weakly electric fish are not only encoded in the number of spikes per electric organ discharge (EOD), as is the case in wave-type electric fish, but also in the spike timing pattern after each EOD, as found in pulse-type Mormyroidea. Present data suggest that pulsant electrogenesis and spike timing coding of electrosensory signals developed concomitantly in the same species, and evolved convergently in African and American electric fish.

scholarly journals Calcium Dynamics Encode the Magnitude of a Graded Memory Underlying Sensorimotor Adaptation

2010 ◽  
Vol 103 (5) ◽  
pp. 2372-2381 ◽  
Author(s):  
Nikolai C. Dembrow ◽  
Diana L. Pettit ◽  
Harold H. Zakon
Keyword(s):  
Electric Fish ◽  
Neural Correlates ◽  
Weakly Electric Fish ◽  
Intrinsic Excitability ◽  
Sensorimotor Adaptation ◽  
Neural Correlate ◽  
Wide Range ◽  
Excitability Of Neurons ◽  
Weakly Electric

The role of Ca2+ in the induction of neural correlates of memory has frequently been described in binary terms despite the fact that many forms of memory are graded in their strength and/or persistence. We find that Ca2+ dynamics encode the magnitude of sensorimotor adaptation of the electromotor output in a weakly electric fish. The neural correlate of this memory is a synaptically induced Ca2+-dependent enhancement of intrinsic excitability of neurons responsible for setting the electromotor output. Changes in Ca2+ during induction accurately predict the magnitude of this graded memory over a wide range of stimuli. Thus despite operating over a range from seconds to tens of minutes, the encoding of graded memory can be mediated by a relatively simple cellular mechanism.

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