Modulation of inspiratory burst duration and frequency by bombesin in vitro.

Autor: Morgado-Valle C; Instituto de Investigaciones Cerebrales, Dirección General de Investigaciones, Universidad Veracruzana, Xalapa Veracruz, México, 91190. comorgado@uv.mx.; Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke (NINDS). National Institutes of Health (NIH), Bethesda, MD, 20892, USA. comorgado@uv.mx., Smith JC; Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke (NINDS). National Institutes of Health (NIH), Bethesda, MD, 20892, USA., Fernandez-Ruiz J; Facultad de Medicina, Universidad Nacional Autónoma de México. Ciudad de México, México City, 04510, México., Lopez-Meraz L; Instituto de Investigaciones Cerebrales, Dirección General de Investigaciones, Universidad Veracruzana, Xalapa Veracruz, México, 91190., Beltran-Parrazal L; Instituto de Investigaciones Cerebrales, Dirección General de Investigaciones, Universidad Veracruzana, Xalapa Veracruz, México, 91190. lubeltran@uv.mx.
Jazyk: angličtina
Zdroj: Pflugers Archiv : European journal of physiology [Pflugers Arch] 2023 Jan; Vol. 475 (1), pp. 101-117. Date of Electronic Publication: 2022 Jan 22.
DOI: 10.1007/s00424-022-02663-1
Abstrakt: Mammalian respiratory rhythm-generating circuits in the brainstem are subject to neuromodulation by multiple peptidergic afferent inputs controlling circuit behavior and outputs. Although functionally important, actions of neuropeptide modulators have not been fully characterized. We analyzed at cellular and circuit levels two inspiratory patterns intrinsically generated by the preBötzinger complex (preBötC) and their modulation by the neuropeptides bombesin and substance P (SP) in neonatal rat medullary slices in vitro. We found that, in recordings of hypoglossal nerve and preBötC neuron inspiratory activity, some inspiratory bursts occurring spontaneously under basal conditions have a biphasic shape with longer duration than normal inspiratory bursts and occur at a lower frequency. This biphasic burst pattern has been proposed to represent inspiratory activity underling periodic sighs. Bath-applied bombesin or SP decreased the period and increased the duration of both normal inspiratory and biphasic bursts and their underlying synaptic drives. The ratio of the biphasic long-duration burst period to the normal inspiratory burst period and the ratio of their burst durations remained the same before and after peptidergic modulation. Bombesin increased the frequency of the inspiratory rhythm in a Ca 2+ -independent manner and the frequency of long-duration bursts in a Ca 2+ -dependent manner. This finding suggests that period and burst duration coupling are due to intrinsic mechanisms controlling simultaneously timing and burst termination within the inspiratory rhythm-generating network. We propose a model in which signaling cascades activated by bombesin and SP modulate mechanisms controlling inspiratory burst frequency and duration to coordinate preBötC circuit behavioral outputs.
(© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
Databáze: MEDLINE
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