TY - JOUR

T1 - Oyster Electrophysiology

T2 - Electrocardiogram Signal Recognition and Interpretation

AU - Batista, Frederico M.

AU - Power, Deborah M.

AU - Harrison, Adrian Paul

PY - 2015

Y1 - 2015

N2 - After 100 years of published recording traces pertaining to the oyster electrocardiogram (ECG), we revisited the original experiments of Eiger (1913), using state-of-the-art electrophysiology recorders. Our aim was to confirm that a recordable ECG, similar to that of higher vertebrates, is present in the oyster heart. Portuguese oysters Crassostrea angulata, collected from the Guadiana estuary, Portugal, were used. The oysters were drilled through the right valve to reveal the pericardium. Gold and silver electrodes were placed through the hole and electrophysiological recordings were obtained. Stimulation of the oyster heart was performed in vivo and in vitro using a constant current power supply. Placement of electrodes around the heart revealed a trace that very closely matched the published ECG of Eiger (1913). However, we were unable to confirm that the recording was an ECG of the oyster heart. Moreover, measurements on isolated oyster hearts revealed a low conductivity (0.10 S m‒1). We did, however, record a depolarization signal from what we believe to be the visceral ganglia, and this preceded contractions of the oyster heart. Our findings indicate that so-called ECGs, previously recorded by [2] in Ostrea edulis, but also the “ECG” recorded by [4] in C. virginica from oyster hearts, are in fact an artifact arising from relative movement of the recording electrodes, giving rise to a baseline shift that mimics in some ways the P and QRS features of a typical ECG. Nevertheless, such recordings provide information pertaining to heart rate and are not without importance.

AB - After 100 years of published recording traces pertaining to the oyster electrocardiogram (ECG), we revisited the original experiments of Eiger (1913), using state-of-the-art electrophysiology recorders. Our aim was to confirm that a recordable ECG, similar to that of higher vertebrates, is present in the oyster heart. Portuguese oysters Crassostrea angulata, collected from the Guadiana estuary, Portugal, were used. The oysters were drilled through the right valve to reveal the pericardium. Gold and silver electrodes were placed through the hole and electrophysiological recordings were obtained. Stimulation of the oyster heart was performed in vivo and in vitro using a constant current power supply. Placement of electrodes around the heart revealed a trace that very closely matched the published ECG of Eiger (1913). However, we were unable to confirm that the recording was an ECG of the oyster heart. Moreover, measurements on isolated oyster hearts revealed a low conductivity (0.10 S m‒1). We did, however, record a depolarization signal from what we believe to be the visceral ganglia, and this preceded contractions of the oyster heart. Our findings indicate that so-called ECGs, previously recorded by [2] in Ostrea edulis, but also the “ECG” recorded by [4] in C. virginica from oyster hearts, are in fact an artifact arising from relative movement of the recording electrodes, giving rise to a baseline shift that mimics in some ways the P and QRS features of a typical ECG. Nevertheless, such recordings provide information pertaining to heart rate and are not without importance.

U2 - 10.11131/2015/101127

DO - 10.11131/2015/101127

M3 - Journal article

VL - 3

JO - Open Access Journal of Science and Technology

JF - Open Access Journal of Science and Technology

SN - 2314-5234

M1 - 101127

ER -