Characteristics of the hibernating heart

Dawe, Albert R.; Morrison, Peter

doi:10.1016/0002-8703(55)90031-4

Cited by 82 publications

(29 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…He suggested that similar changes in rate had been overlooked in C. tridecemlineatus and the European hedgehog (Erinaceus) by Dawe and Morrison (1955), and that these changes indicated an increase in sympathetic tone once the deeply hibernating condition had been reached. The present investigation confirms the work of the latter authors, for the slowest and most even rates occur during deep hibernation in C. tridecemlineatus and C. lateralis, and these rates may continue for many hours.…”

Section: Section 5 Discussionmentioning

confidence: 99%

“…Poking either hamster or ground squirrel gives rise to a burst of muscle action potentials, with no visible muscular movement in the hamster, which continue after removal of the stimulus. Cardioacceleration occurs immediately after stimulation in all species of ground squirrel that have been studied (Dawe and Morrison, 1955;Lyman and O'Brien, 1960) as well as in hamsters , woodchucks (Lyman, 1958), and hedgehogs (Dawe and Morrison, 1955). The cardioacceleration associated with the nicotinic effects of acetylcholine does not occur if the ground squirrel has been previously curarized.…”

Section: Section 5 Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Autonomic Control of Circulation During the Hibernating Cycle in Ground Squirrels

Lyman¹,

O'Brien²

1963

View full text Add to dashboard Cite

Section: Section 5 Discussionmentioning

confidence: 99%

Section: Section 5 Discussionmentioning

confidence: 99%

Autonomic Control of Circulation During the Hibernating Cycle in Ground Squirrels

Lyman¹,

O'Brien²

1963

View full text Add to dashboard Cite

“…For instance, in the case of hedgehogs (Erinaceus europaeus), the heart rate drops from ~300 min -1 to ~3 min -1 within a couple of hours upon going into hibernation. 8 Most homeotherms have been relieved of such a dramatic coupling of activity to temperature variations but nevertheless perceive and react to thermal stimuli. 9 Experimentally, studies of the temperature dependence of a process are interesting because they represent a relatively simple means to reveal thermodynamic properties of a system without adding to its compositional complexity.…”

Section: Temperature Dependence Of Action Potential Velocity In Livinmentioning

confidence: 99%

Temperature and excitable cells

Fillafer

Schneider

2013

Communicative & Integrative Biology

View full text Add to dashboard Cite

“…2 3. The hibernator's heart has a relatively short QT interval at normal temperature (see Figure 6 in Dawe and Morrison 22 ). 4.…”

Section: Other Factors Relevant To Avoiding Arrhythmias: Future Researchmentioning

confidence: 99%

“…23 Under certain conditions it may be described as a "T complex," based on its similarity to the QRS complex, rather than a T wave. 22,23 Alternatively, a T wave may be virtually lacking (see Figure 6 in Dawe and Morrison 22 and Figure 4 in Biürck and Johansson 23 ). 5.…”

Section: Other Factors Relevant To Avoiding Arrhythmias: Future Researchmentioning

confidence: 99%

The hidden secrets of the hibernator’s heart may protect against arrhythmias

Heyden

Opthof

2005

Heart Rhythm

View full text Add to dashboard Cite

In this issue of Heart Rhythm, Fedorov et al 1 describe the activation pattern and other electrophysiologic features of the heart of Citellus undulatus (also known as Spermophilus undulatus), the Siberian ground squirrel, both in summer active and in winter hibernating animals at temperatures varying from 3°C to 37°C and compared those with data in the rabbit heart as a nonhibernating species. The summary of the data can be simple. There is a substantial decrease in conduction velocity from 70 -80 cm/s in the Siberian ground squirrel at 37°C to 5-10 cm/s at 3°C. However, the conduction patterns remain normal and do not show areas of substantial conduction block, which might herald arrhythmias. Interestingly, conduction velocity was significantly higher in hearts obtained from winter hibernating animals than from summer active animals at both 37°C and 3°C. Data at such low temperatures cannot be obtained from the hearts in nonhibernating species such as the rabbit in the present study, but also not in man, because their hearts become quiescent or develop ventricular fibrillation at temperatures below 20°C. 1,2 Moreover, the authors show that there is an up-regulation of connexin43 (Cx43) in working ventricular myocardium of hibernating animals, in line with previous research, 3 and an appearance of connexin45 (Cx45) in working ventricular myocardium, although the expression of the latter normally is restricted to the conduction system. 4 This study underscores the presence of differences not only between hibernating and nonhibernating species but also between hibernating and nonhibernating individuals of the same species, with all the interesting implications for regulatory mechanisms. Physiologic background and implicationsWe would like to point out first that hypothermia impairs conduction velocity by a combined effect on the underlying membrane currents and on gap junctions. The conductance of gap junctions is reduced by about 70% when the temperature drops from normal to 0°C at least in cell pairs of neonatal rat heart. 5 Whether the inward Na ϩ current is operational at temperatures well below 10°C is questionable because it is seriously impaired at much smaller drops in temperature than those observed in hibernators. 6,7 Liu et al 8 reported that the L-type Ca 2ϩ current virtually disappears at 10°C in rat ventricular myocytes, although rat ventricle is relatively resistant against low temperature compared with other mammals. In contrast, the L-type Ca 2ϩ current has the same amplitude in hedgehog papillary muscle in the temperature range from 10°C to 35°C. 8 It is not possible to decide whether conduction remains intact, although impaired, in hibernators at temperatures well below 10°C because their membrane currents are relatively resistant against low temperature or because their gap junctions function better at low temperature compared with nonhibernators. Of note, in this study arrhythmias did not develop despite conduction velocities of 5 cm/s in the hearts from summer active animals at 3°C and conduc...

show abstract

Characteristics of the hibernating heart

Cited by 82 publications

References 11 publications

Autonomic Control of Circulation During the Hibernating Cycle in Ground Squirrels

Autonomic Control of Circulation During the Hibernating Cycle in Ground Squirrels

Temperature and excitable cells

The hidden secrets of the hibernator’s heart may protect against arrhythmias

Contact Info

Product

Resources

About