title: From the intrinsic properties to the functional role of a neuron phenotype: an example from electric fish during signal trade-off.
abstract: This review deals with the question: what is the relationship between the properties of a neuron and the role that the neuron plays within a given neural circuit? Answering this kind of question requires collecting evidence from multiple neuron phenotypes and comparing the role of each type in circuits that perform well-defined computational tasks. The focus here is on the spherical neurons in the electrosensory lobe of the electric fish Gymnotus omarorum. They belong to the one-spike-onset phenotype expressed at the early stages of signal processing in various sensory modalities and diverse taxa. First, we refer to the one-spike neuron intrinsic properties, their foundation on a low-threshold K(+) conductance, and the potential roles of this phenotype in different circuits within a comparative framework. Second, we present a brief description of the active electric sense of weakly electric fish and the particularities of spherical one-spike-onset neurons in the electrosensory lobe of G. omarorum. Third, we introduce one of the specific tasks in which these neurons are involved: the trade-off between self- and allo-generated signals. Fourth, we discuss recent evidence indicating a still-undescribed role for the one-spike phenotype. This role deals with the blockage of the pathway after being activated by the self-generated electric organ discharge and how this blockage favors self-generated electrosensory information in the context of allo-generated interference. Based on comparative analysis we conclude that one-spike-onset neurons may play several functional roles in animal sensory behavior. There are specific adaptations of the neuron's 'response function' to the circuit and task. Conversely, the way in which a task is accomplished depends on the intrinsic properties of the neurons involved. In short, the role of a neuron within a circuit depends on the neuron and its functional context.
authors.affiliation: Departamento de Histología y Embriología, Facultad de Medicina, Universidad de la República, Avenida General Flores, 2125 Montevideo, Uruguay.
authors.forename: Javier
authors.initials: J
authors.lastname: Nogueira
authors.forename: Angel A
authors.initials: AA
authors.lastname: Caputi
mesh_terms: D000818:Animals; D004557:Electric Organ / Q000502:physiology*; D023702:Gymnotiformes / Q000502:physiology*; D009415:Nerve Net / Q000166:cytology / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D010641:Phenotype; D012677:Sensation
keywords: allo-generated signal; fast electrosensory pathway; intrinsic properties; one-spike-onset neuron; self-generated signal