{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,31]],"date-time":"2026-07-31T06:00:47Z","timestamp":1785477647718,"version":"3.56.0"},"reference-count":47,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,7,31]],"date-time":"2026-07-31T00:00:00Z","timestamp":1785456000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Neurosci."],"abstract":"<jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>Although hypoxic interventions are increasingly explored as non-pharmacological modulators of stress-related pathology, their ability to benefit PTSD remains poorly understood. We compared behavioural and molecular outcomes of three hypoxic regimes \u2014 intermittent normobaric hypoxia (IHT), hypobaric hypoxia (Bar), and chemical hypoxia (CH) via cobalt chloride (CoCl\u2082) \u2014 in rats with PTSD induced by single prolonged stress (SPS).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      Male albino rats (\n                      <jats:italic>n<\/jats:italic>\n                      = 105; eight groups) received one of the three treatments after control or SPS conditioning. Anxiety-like behaviour was assessed by Elevated Plus Maze (EPM), Open Field Test (OFT), and Dark-Light Box (DLB); HIF-1\u03b1, HIF-2\u03b1, HIF-3\u03b1, PACAP, and PAI-1 mRNA were quantified in the medial prefrontal cortex (mPFC) and hippocampus by real-time qPCR.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Mild IHT was the only regimen to produce robust PTSD-specific anxiolysis: PTSD+IHT animals showed a four-fold reduction in EPM freezing relative to Control+IHT (5.4 \u00b1 4.9 vs 21.6 \u00b1 14.9 s;\n                      <jats:italic>p<\/jats:italic>\n                      &amp;lt; 0.01), a near four-fold reduction in OFT freezing (30.3 \u00b1 8.6 vs 119.9 \u00b1 46.3 s;\n                      <jats:italic>p<\/jats:italic>\n                      &amp;lt; 0.001), and greater open-arm engagement. CH and Bar produced limited or no behavioural benefit. All three regimes substantially reduced HIF-1\u03b1 mRNA and strongly reduced PAI-1 (&amp;gt;20-fold in most groups;\n                      <jats:italic>p<\/jats:italic>\n                      \u2264 0.001) irrespective of trauma status. Only HIF-1\u03b1 was significantly elevated in the hippocampus of untreated PTSD animals relative to controls (2.78 \u00b1 1.97 vs 1.10 \u00b1 0.50;\n                      <jats:italic>q<\/jats:italic>\n                      = 0.039); HIF-2\u03b1 and HIF-3\u03b1 showed a similar, non-significant upward trend (both ns after FDR correction, reflecting wide between-animal variability). Group means for all three HIF subunits converged toward the control range under all three interventions. HIF-3\u03b1 responses to IHT or Bar were consistently blunted in PTSD animals across both regions, while PACAP was uniformly suppressed with stronger trauma-dependent attenuation under Bar.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Discussion<\/jats:title>\n                    <jats:p>As protein-level and canonical HIF target-gene readouts were not assessed, the reported transcript changes should be interpreted as a downstream feedback signature rather than a direct index of functional HIF activity. Hypoxic modality, not hypoxia per se, determines behavioural and molecular responses in PTSD; mild IHT uniquely normalised both in traumatised animals, supporting its development as a state-dependent non-pharmacological intervention for trauma-related conditions.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fnins.2026.1904848","type":"journal-article","created":{"date-parts":[[2026,7,31]],"date-time":"2026-07-31T05:38:16Z","timestamp":1785476296000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Mode-dependent effects of chemical, intermittent, and hypobaric hypoxia on HIF-1\u03b1, HIF-2\u03b1, HIF-3\u03b1, PACAP, and PAI mRNA expression in the single prolonged stress model of PTSD"],"prefix":"10.3389","volume":"20","author":[{"given":"Denys","family":"Porkhalo","sequence":"first","affiliation":[{"name":"Department of General and Molecular Pathophysiology, Bogomoletz Institute of Physiology of NAS of Ukraine","place":["Kyiv, Ukraine"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Denys","family":"Pashevin","sequence":"additional","affiliation":[{"name":"Department of General and Molecular Pathophysiology, Bogomoletz Institute of Physiology of NAS of Ukraine","place":["Kyiv, Ukraine"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yana","family":"Naumenko","sequence":"additional","affiliation":[{"name":"Department of Biophysics of Sensory Signalling, Bogomoletz Institute of Physiology of NAS of Ukraine","place":["Kyiv, Ukraine"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Roman","family":"Koval","sequence":"additional","affiliation":[{"name":"Department of Cytology, Bogomoletz Institute of Physiology of NAS of Ukraine","place":["Kyiv, Ukraine"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mariia","family":"Kozlovska","sequence":"additional","affiliation":[{"name":"Department of Hypoxia, Bogomoletz Institute of Physiology of NAS of Ukraine","place":["Kyiv, Ukraine"]},{"name":"International Centre for Astronomical and Medico-Ecological Research, NAS of Ukraine","place":["Kyiv, Ukraine"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mariia","family":"Kamkina","sequence":"additional","affiliation":[{"name":"Kyiv Medical University","place":["Kyiv, Ukraine"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yan","family":"Tytarenko","sequence":"additional","affiliation":[{"name":"Bogomolets National Medical University","place":["Kyiv, Ukraine"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alla","family":"Portnychenko","sequence":"additional","affiliation":[{"name":"Department of Hypoxia, Bogomoletz Institute of Physiology of NAS of Ukraine","place":["Kyiv, Ukraine"]},{"name":"International Centre for Astronomical and Medico-Ecological Research, NAS of Ukraine","place":["Kyiv, Ukraine"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Victor","family":"Dosenko","sequence":"additional","affiliation":[{"name":"Department of General and Molecular Pathophysiology, Bogomoletz Institute of Physiology of NAS of Ukraine","place":["Kyiv, Ukraine"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,7,31]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"1337","DOI":"10.3389\/fphys.2018.01337","article-title":"Daily intermittent normobaric hypoxia over 2 weeks reduces BDNF plasma levels in young adults \u2013 a randomized controlled feasibility study","volume":"9","author":"Becke","year":"2018","journal-title":"Front. 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