Operant conditioning of heart rate in curarized rats: hemodynamic changes
Insights
Operant conditioning of heart rate in rats significantly impacted cardiac output. Decreasing heart rate led to the most substantial cardiovascular changes, highlighting the interconnectedness of cardiovascular parameters.
Area of Science:
- Cardiovascular Physiology
- Behavioral Neuroscience
Background:
- Operant conditioning is a learning process where behavior is modified by consequences.
- Understanding the autonomic nervous system's control over cardiovascular function is crucial.
Purpose of the Study:
- To investigate the effects of operant heart rate conditioning on cardiac output, mean arterial pressure, and total peripheral resistance in curarized rats.
- To determine how conditioning specific heart rate responses influences other cardiovascular parameters.
Main Methods:
- Three groups of curarized rats underwent operant conditioning using a shock-avoidance procedure.
- Measurements included heart rate, cardiac output, mean arterial pressure, and total peripheral resistance.
- Groups were conditioned to increase heart rate, decrease heart rate, or served as controls.
Main Results:
- Control rats showed stable heart rate but decreased cardiac output.
- Rats conditioned to increase heart rate had minimal heart rate changes and decreased cardiac output.
- Rats conditioned to decrease heart rate exhibited significant heart rate reduction and a pronounced decrease in cardiac output.
Conclusions:
- Operant conditioning of a single cardiovascular parameter, like heart rate, can induce significant alterations in other cardiovascular measures.
- The physiological effects of curare may partially mask these changes.
- Comprehensive assessment of multiple cardiovascular functions is essential for interpreting operant heart rate conditioning results.
Abstract:
Three groups of curarized rats were subjected to operant heart rate conditioning with use of a shock-avoidance procedure while cardiac output, mean arterial pressure, and total peripheral resistance were measured. Heart rate changes in the control group remained constant during the entire 90-min experimental period, while cardiac output decreased significantly. Those rats that were reinforced for increasing their heart rate had a small but statistically significant increase in heart rate, but cardiac output decreased to approximately the same extent as in the control group. The group reinforced for decreasing their heart rate demonstrated a large, significant decrease in heart rate and an even larger drop in cardiac output, which was significantly greater than that of either of the other two groups. Operant conditioning of a single facet of the cardiovascular system resulted in significantly larger changes in other cardiovascular parameters, which may have been partly masked by the physiological effects of d-tubocurarine. Therefore, only when these other measures of cardiovascular function are taken into consideration can interpretation of operant heart rate conditioning become meaningful.
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