An in vitro experimental model for analysis of central control of sympathetic nerve activity
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Newborn rat brainstem-spinal cord preparations are useful for in vitro analysis of various brainstem functions including respiratory activity. When studying the central control of sympathetic nerve activity (SNA), it is important to record peripheral outputs of the SNA. We developed an in vitro preparation in which neuronal connections between the cardiovascular center in the medulla and SNA peripheral outputs are preserved. Zero- to 1-day-old rats were deeply anesthetized with isoflurane, and the brainstem and spinal cord were isolated with a partial right thoracic cage to record sympathetic nerve discharge from the right thoracic sympathetic nerve trunk (T9–T11). SNA in this preparation was strongly modulated by inspiratory activity. Single-shot electrical stimulation of the ipsilateral rostral ventrolateral medulla (RVLM) induced a transient increase of SNA. Bath application of angiotensin II induced an increase of SNA, and local ipsilateral microinjection of angiotensin II to the RVLM induced a transient increase of SNA. This preparation allows analysis of the central control of the SNA in vitro.
KeywordsSympathetic nerve activity Respiratory activity In vitro Angiotensin II Newborn rat
YO, KI, and HO designed and performed the electrophysiological recordings, analyzed the data, and wrote the manuscript. YM, TO and MI helped to draft the manuscript. All authors approved the final version of the manuscript.
Complaince with ethical standards
This work was supported by Grants-in Aid for Scientific Research (KAKENHI: 15K01835, 25461070).
Conflict of interest
The authors declare that they have no conflict of interest.
- 3.Su CK (1999) Rhythmic sympathetic nerve discharges in an in vitro neonatal rat brain stem-spinal cord preparation. J Appl Physiol (1985) 87:1066–1074Google Scholar
- 6.Oshima N, Kumagai H, Onimaru H, Kawai A, Pilowsky PM, Iigaya K, Takimoto C, Hayashi K, Saruta T, Itoh H (2008) Monosynaptic excitatory connection from the rostral ventrolateral medulla to sympathetic preganglionic neurons revealed by simultaneous recordings. Hypertens Res 31:1445–1454CrossRefPubMedGoogle Scholar
- 23.Sakata K, Kumagai H, Osaka M, Onami T, Matsuura T, Imai M, Saruta T (2002) Potentiated sympathetic nervous and renin–angiotensin systems reduce nonlinear correlation between sympathetic activity and blood pressure in conscious spontaneously hypertensive rats. Circulation 106:620–625CrossRefPubMedGoogle Scholar