Electrical Synapses in Fishes: Their Relevance to Synaptic Transmission

The elucidation of the mechanisms of communication between neurons involved the use of identifiable cell contacts from various animal species, which offered the required experimental accessibility for these investigations. Within this context seminal observations in fishes were foundational in what we recognize today as "synaptic electrical transmission." Moreover, fish electrical synapses first revealed the functional contributions of this modality of transmission to vertebrate neural circuits and provided early evidence of their plastic properties. Present and future investigations in genetically tractable species will shed light on the molecular mechanisms and functional diversity of electrical transmission in the vertebrate brain. This chapter discusses the past, present, and potential future contributions of fish electrical synapses to the understanding of synaptic communication in general.