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Microglia Modulate Changes in Dorsal Motor Nucleus (DMNV) Neuron Excitability Following Sustained Hypoxia Exposure During a Critical Period of Neonatal Development
Author(s) -
Mayer Catherine,
Mac Farlane Peter
Publication year - 2019
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2019.33.1_supplement.730.5
Subject(s) - dorsal motor nucleus , microglia , brainstem , excitatory postsynaptic potential , neuroscience , hypoxia (environmental) , minocycline , neuron , medicine , endocrinology , patch clamp , biology , electrophysiology , chemistry , vagus nerve , inhibitory postsynaptic potential , inflammation , organic chemistry , stimulation , oxygen , microbiology and biotechnology , antibiotics
We showed previously that the respiratory neural control system exhibits a lethal vulnerability to sustained hypoxia (SH) exposure during the second postnatal week of life (SH=11% O 2 , postnatal (P) day 11–15). The vulnerability was associated with increased microglia expression and decreased serotonin (5‐HT) expression in the dorsal motor nucleus of vagus (DMNV), an area of the brainstem containing vagal preganglionic neurons which provide parasympathetic outflow to the heart (and viscera). We hypothesized that this increased microglia expression was associated with increased activity of DMNV neurons and that this could be reversed by treatment with minocycline, an inhibitor of microglia activation. We used whole‐cell patch clamp recordings to examine the excitatory properties of DMNV neurons in neonatal (P16) rats treated with SH from P11–P15. A subset of these animals received subQ injections of minocycline on P11, P13, and P15. SH exposure increased the frequency and amplitude of spontaneous EPSCs in DMNV neurons compared to normoxic (NX) rats; rise time, decay time, and area of the spontaneous EPSC's did not differ between groups. Minocycline treatment during SH prevented the increase in frequency and amplitude seen with SH exposure alone. In conclusion, neurons from the DMNV of SH exposed animals exhibit increased excitability suggesting increased vagal tone in vivo – an effect that appears modulated by microglia. These data may be important to understanding the potential effects of inadequate oxygenation on parasympathetic modulation of heart rate during particularly vulnerable periods of cardiorespiratory development. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .