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Consequences of neonatal sustained and intermittent hypoxia on spontaneous and evoked activities of nucleus tractus solitarius (nTS) neurons
Author(s) -
Mayer Catherine Ann,
Wilson Christopher,
MacFarlane Peter
Publication year - 2013
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.27.1_supplement.1207.3
Subject(s) - excitatory postsynaptic potential , solitary tract , solitary nucleus , hypoxia (environmental) , electrophysiology , medicine , patch clamp , endocrinology , nucleus , medulla oblongata , neuroscience , anesthesia , central nervous system , chemistry , inhibitory postsynaptic potential , biology , oxygen , organic chemistry
We showed previously that neonatal sustained hypoxia (SH=11% O 2 , postnatal (P) day 1–5) followed by chronic intermittent hypoxia (CIH=5%O 2 45s/5min 8 hrs/day, P5‐P15) attenuated the ventilatory response to acute hypoxia. We hypothesized that this attenuated response was associated with impaired activity of neurons in an area of chemoafferent integration, the nucleus tractus solitarius (nTS). We used whole‐cell patch clamp recordings to examine the excitatory properties of nTS neurons monosynaptically connected to the solitary tract in neonatal (P16) rats treated with SH prior to CIH (SH+CIH). SH+CIH exposure decreased the frequency of spontaneous EPSCs in nTS neurons compared to normoxic rats. Amplitude, rise time, decay time, and area did not differ. The amplitude of evoked EPSCs in monosynaptically connected nTS neurons was increased in the SH+CIH group compared to normoxic rats. Contrary to our hypothesis, neurons from the nTS of SH+CIH exposed animals exhibit increased excitability ( evoked responses), which may be a compensatory mechanism resulting from neonatal hypoxia. These data may be important to understanding the potential effects of inadequate oxygenation in the neonatal period on nTS neurons.