The bodymind. It is crucial that heart rate and blood pressure oscillate in phase with breathing cycles to keep our vitals within healthy ranges or adapt to sudden physical efforts. Here the authors show that’s the function of respiratory rhythm-generating neurons in the preBötzinger complex at the base of the brain. The job is split between inhibitory and excitatory subtypes, with the former entraining cardio-inhibitory neuron activity and heart beats and the latter entraining vaso-constricting neuron activity and blood pressure. The preBötzingers or how to sync head and body. (by I.Bureau)
Paru dans Elife, Juin 2020
Auteurs: C Menuet, A Connelly, J Bassi, M Melo, S Le, J Kamar, NN Kumar, SJ McDougall, S McMullan, AM Allen
Scientific abstract: Heart rate and blood pressure oscillate in phase with respiratory activity. A component of these oscillations is generated centrally, with respiratory neurons entraining the activity of pre- sympathetic and parasympathetic cardiovascular neurons. Using a combination of optogenetic inhibition and excitation in vivo and in situ in rats, as well as neuronal tracing, we demonstrate that preBötzinger Complex (preBötC) neurons, which form the kernel for inspiratory rhythm generation, directly modulate cardiovascular activity. Specifically, inhibitory preBötC neurons modulate cardiac parasympathetic neuron activity whilst excitatory preBötC neurons modulate sympathetic vasomotor neuron activity, generating heart rate and blood pressure oscillations in phase with respiration. Our data reveal yet more functions entrained to the activity of the preBötC, with a role in generating cardiorespiratory oscillations. The findings have implications for cardiovascular pathologies, such as hypertension and heart failure, where respiratory entrainment of heart rate is diminished and respiratory entrainment of blood pressure exaggerated.