{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,29]],"date-time":"2026-10-29T22:32:16Z","timestamp":1793313136168,"version":"4.5.0"},"reference-count":56,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2025,7,24]],"date-time":"2025-07-24T00:00:00Z","timestamp":1753315200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Biology"],"abstract":"<jats:p>Hypoxia can adversely affect multiple organ systems. This study investigated the impact of intermittent hypoxia on serotonin levels and depression-like behaviors across distinct neuroanatomical regions. Sixteen adult female Wistar albino rats were divided into two groups: control (n = 8) and hypoxia (n = 8). The hypoxia group was exposed to a simulated altitude of 3000 for 5 h daily over 14 days. Behavioral assessments included locomotor activity (open field test) and depression-like behaviors (forced swimming test). Serotonin levels were quantified via ELISA in the prefrontal cortex, striatum, thalamus, hypothalamus, hippocampus, and serum. Intermittent hypoxia did not alter locomotor activity (p &gt; 0.05) but significantly increased depression-like behavior (p &lt; 0.05), accompanied by a pronounced reduction in swimming behavior (p &lt; 0.0001), a marker associated with serotonergic function. Serotonin levels were significantly reduced in the prefrontal cortex (p &lt; 0.005) and striatum (p &lt; 0.05), while no changes were observed in other regions or serum (p &gt; 0.05). These findings demonstrate that intermittent hypoxia induces depression-like behaviors and region-specific serotonin depletion, particularly in the prefrontal cortex and striatum. This underscores the need to evaluate hypoxia-related brain health implications in conditions such as sleep apnea and acute mountain sickness.<\/jats:p>","DOI":"10.3390\/biology14080931","type":"journal-article","created":{"date-parts":[[2025,7,24]],"date-time":"2025-07-24T11:58:53Z","timestamp":1753358333000},"page":"931","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Hypoxia Disrupted Serotonin Levels in the Prefrontal Cortex and Striatum, Leading to Depression-like Behavior"],"prefix":"10.3390","volume":"14","author":[{"given":"Hasan","family":"\u00c7al\u0131\u015fkan","sequence":"first","affiliation":[{"name":"Department of Physiology, School of Medicine, Bal\u0131kesir University, Bal\u0131kesir 10145, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3437-6500","authenticated-orcid":false,"given":"Koray Hamza","family":"Cihan","sequence":"additional","affiliation":[{"name":"Department of Psychiatry, School of Medicine, Ankara University, Ankara 06230, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Seda","family":"Ko\u00e7ak","sequence":"additional","affiliation":[{"name":"Department of Physiology, School of Medicine, K\u0131r\u015fehir Ahi Evran University, K\u0131r\u015fehir 40100, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4513-1907","authenticated-orcid":false,"given":"G\u00f6zde","family":"Karabulut","sequence":"additional","affiliation":[{"name":"Department of Biology, Faculty of Arts and Science, K\u00fctahya Dumlup\u0131nar University, K\u00fctahya 43100, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Erhan","family":"Nal\u00e7ac\u0131","sequence":"additional","affiliation":[{"name":"Department of Physiology, School of Medicine, Ankara University, Ankara 06230, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,7,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"374","DOI":"10.1016\/j.bbi.2007.01.010","article-title":"Depressive disorders and immunity: 20 years of progress and discovery","volume":"21","author":"Irwin","year":"2007","journal-title":"Brain Behav. 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