The role of the dorsomedial hypothalamus in the cardiogenic sympathetic reflex in rats
Author Information
Author(s): Zahner Matthew R., Hillard Kynlee J., Chandley Michelle C.
Primary Institution: East Tennessee State University
Hypothesis
Muscimol inhibition of the DMH attenuates and bicuculline disinhibition of the DMH augments the cardiogenic sympathoexcitatory reflex in the Sprague-Dawley rat.
Conclusion
The study suggests that sympathetic activity derived from the DMH does not play an important role in the cardiogenic sympathetic afferent reflex in Sprague Dawley rats.
Supporting Evidence
- Muscimol inhibition significantly reduced baseline arterial pressure and heart rate.
- Bicuculline disinhibition increased baseline arterial pressure, heart rate, and renal sympathetic nerve activity.
- The reflex response to epicardial bradykinin was not augmented by bicuculline disinhibition.
Takeaway
This study looked at how a part of the brain called the DMH affects heart responses in rats when they feel heart pain. It found that this part of the brain doesn't really help the heart respond to that pain.
Methodology
The study involved measuring arterial pressure, heart rate, and renal sympathetic nerve activity responses to epicardial bradykinin in anesthetized Sprague Dawley rats before and after microinjection of muscimol or bicuculline into the DMH.
Limitations
Five rats were excluded from the analysis due to inaccurate microinjection outside the DMH.
Participant Demographics
Adult male Sprague-Dawley rats, 10–14 weeks old, weighing 300–400 g.
Statistical Information
P-Value
p<0.001
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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