title: Spike-interval triggered averaging reveals a quasi-periodic spiking alternative for stochastic resonance in catfish electroreceptors.
abstract: Catfish detect and identify invisible prey by sensing their ultra-weak electric fields with electroreceptors. Any neuron that deals with small-amplitude input has to overcome sensitivity limitations arising from inherent threshold non-linearities in spike-generation mechanisms. Many sensory cells solve this issue with stochastic resonance, in which a moderate amount of intrinsic noise causes irregular spontaneous spiking activity with a probability that is modulated by the input signal. Here we show that catfish electroreceptors have adopted a fundamentally different strategy. Using a reverse correlation technique in which we take spike interval durations into account, we show that the electroreceptors generate a supra-threshold bias current that results in quasi-periodically produced spikes. In this regime stimuli modulate the interval between successive spikes rather than the instantaneous probability for a spike. This alternative for stochastic resonance combines threshold-free sensitivity for weak stimuli with similar sensitivity for excitations and inhibitions based on single interspike intervals.
authors.affiliation: Experimental Zoology, Wageningen University, Wageningen, The Netherlands. martin.lankheet@wur.nl
authors.forename: Martin J M
authors.initials: MJ
authors.lastname: Lankheet
authors.forename: P Christiaan
authors.initials: PC
authors.lastname: Klink
authors.forename: Bart G
authors.initials: BG
authors.lastname: Borghuis
authors.forename: André J
authors.initials: AJ
authors.lastname: Noest
mesh_terms: D000818:Animals; D004558:Electric Stimulation; D004560:Electricity; D055724:Electrophysiological Phenomena; D007059:Ictaluridae / Q000502:physiology*; D008959:Models, Neurological; D009474:Neurons / Q000166:cytology*; D010507:Periodicity; D013269:Stochastic Processes