Autonomic Regulation of the Goldfish Intact Heart.

Autonomic regulation plays a central role in cardiac contractility and excitability in numerous vertebrate species. However, the role of autonomic regulation is less understood in fish physiology. Here, we used Goldfish as a model to explore the role of autonomic regulation.

Thermal modulation of epicardial Ca2+ dynamics uncovers molecular mechanisms of Ca2+ alternans.

Ca2+ alternans (Ca-Alts) are alternating beat-to-beat changes in the amplitude of Ca2+ transients that frequently occur during tachycardia, ischemia, or hypothermia that can lead to sudden cardiac death. Ca-Alts appear to result from a variation in the amount of Ca2+ released from the sarcoplasmic reticulum (SR) between two consecutive heartbeats. This variable Ca2+ release has been attributed to the alternation of the action potential duration, delay in the recovery from inactivation of RYR Ca2+ release channel (RYR2), or an incomplete Ca2+ refilling of the SR.

Excitation-Contraction Coupling in the Goldfish () Intact Heart.

Cardiac physiology of fish models is an emerging field given the ease of genome editing and the development of transgenic models. Several studies have described the cardiac properties of zebrafish (). The goldfish () belongs to the same family as the zebrafish and has emerged as an alternative model with which to study cardiac function.

How Ca influx is attenuated in the heart during a "fight or flight" response.

Bazmi and Escobar highlight a recent investigation of the mechanisms that regulate Ca influx during sympathetic stimulation.