Converging electroreceptor cells improve sensitivity and tuning

• Published in: Neuroscience Vol. 81; no. 1; pp. 297 - 301
• Main Authors: Peters, R.C, Brans, R.J, Bretschneider, F, Versteeg, E, Went, A
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-11-1997; Elsevier
• Subjects: Action Potentials - physiology; Animals; Biological and medical sciences; convergence; Electric Organ - innervation; Electric Organ - physiology; Electrophysiology; electroreception; Fundamental and applied biological sciences. Psychology; Ictaluridae - physiology; integration; Neurons, Afferent - physiology; sensory neuron; Sensory Thresholds - physiology; Skin - innervation; Somesthesis and somesthetic pathways (proprioception, exteroception, nociception); interoception; electrolocation. Sensory receptors; summation; Synaptic Transmission - physiology; transmission; Vertebrates: nervous system and sense organs; sensory neuron; transmission; convergence; electroreception; integration; PSH, peristimulus histogram; summation; Electroreceptor; Integration; Discharge pattern; Electrophysiology; Cluster; Tuning; Signal transduction; Vertebrata; Pisces; Information processing; Sensorial perception; Sensory neuron; Ampullary organ
• ISSN: 0306-4522; 1873-7544
• DOI: 10.1016/S0306-4522(97)00190-5

We studied the effect of convergent clustering of ampullary electroreceptor organs on stimulus transduction and transmission in the catfish
Icalurus melas by electrophysiologically recording primary afferent activity of single ampullae (singlets) and pairs (doublets) innervated by the same afferent. Doublets were twice as sensitive as singlets, and showed sharper tuning around the best frequency. The slope of the phase curve in the doublets was slightly steeper than in the singlets. The spontaneous activity and scatter in interspike interval were not correlated with clustering.
The implications of these findings for signal averaging in sensory neurons and their relevance for behaviour are discussed.