The nucleus of the solitary tract and the coordination of respiratory and sympathetic activities.

Zoccal DB, Furuya WI, Bassi M, Colombari DS, Colombari E. Front Physiol. 2014 Jun 25;5:238 I read this review paper because I wanted to learn a little bit more about the inputs to the RVLM, and this paper covered a lot of how the NTS plays a role in regulating sympathetic activity. They talk about how sympathetic nerve activity shows rhythmic activity even after vagotomy and decerebration, presumably because the ventral respiratory column (BotC, pre-BotC, rVRG, and cVRT) either activate or inactivate rhythmicity via the RVLM or CVLM. However, since different nerves (like the phrenic and assorted sympatheticnerves) can have their rhythmicity decoupled by different stimuli, other areas are involved in the pattern generation, like the NTS. The NTS is primarily regulated by a combination of glu and ATP, resulting in changes in SNA. However, NTS microinjection of ACh will increase phrenic nerve activity, but not SNA – suggesting that its control of different groups is regulated by different neurotransmitters. It’s even more complicated in that the NTS has subdivisions that will receive input from some regions but not others, even though some inputs go to multiple subdivisions. To bring it all back to neurogenic hypertension, they did mention that in SHR rats, removal of the carotid chemoreceptor or lesioning the caudal NTS will reduce SNA, suggesting that somehow the chemoreceptor induces the NTS to increase sympathetic tone, maybe through activation of the RVLM? -DH