Hippocampal neurons respond to brain activity with functional hypoxia

• Published in: Molecular psychiatry Vol. 26; no. 6; pp. 1790 - 1807
• Main Authors: Butt, Umer Javed, Steixner-Kumar, Agnes A., Depp, Constanze, Sun, Ting, Hassouna, Imam, Wüstefeld, Liane, Arinrad, Sahab, Zillmann, Matthias R., Schopf, Nadine, Fernandez Garcia-Agudo, Laura, Mohrmann, Leonie, Bode, Ulli, Ronnenberg, Anja, Hindermann, Martin, Goebbels, Sandra, Bonn, Stefan, Katschinski, Dörthe M., Miskowiak, Kamilla W., Nave, Klaus-Armin, Ehrenreich, Hannelore
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.06.2021; Nature Publishing Group
• Subjects: 13/1; 13/51; 14/1; 14/19; 14/34; 14/35; 14/63; 38/1; 38/22; 38/35; 38/77; 38/90; 38/91; 45/91; 631/337; 631/378; 64/60; 82/1; 82/29; 82/51; 96/44; Behavioral Sciences; Biological Psychology; Cognitive ability; Complications and side effects; Gene expression; Health aspects; Hippocampal plasticity; Hippocampus; Hippocampus (Brain); Hypoxia; Hypoxia-inducible factor 1a; Medicine; Medicine & Public Health; Neurons; Neuroplasticity; Neurosciences; Pharmacotherapy; Physical activity; Physiological aspects; Psychiatry; Recombinase; Respiration; Transgenic mice; Well being; Germany
• ISSN: 1359-4184; 1476-5578; 1476-5578
• DOI: 10.1038/s41380-020-00988-w

Physical activity and cognitive challenge are established non-invasive methods to induce comprehensive brain activation and thereby improve global brain function including mood and emotional well-being in healthy subjects and in patients. However, the mechanisms underlying this experimental and clinical observation and broadly exploited therapeutic tool are still widely obscure. Here we show in the behaving brain that physiological (endogenous) hypoxia is likely a respective lead mechanism, regulating hippocampal plasticity via adaptive gene expression. A refined transgenic approach in mice, utilizing the oxygen-dependent degradation (ODD) domain of HIF-1α fused to CreERT2 recombinase, allows us to demonstrate hypoxic cells in the performing brain under normoxia and motor-cognitive challenge, and spatially map them by light-sheet microscopy, all in comparison to inspiratory hypoxia as strong positive control. We report that a complex motor-cognitive challenge causes hypoxia across essentially all brain areas, with hypoxic neurons particularly abundant in the hippocampus. These data suggest an intriguing model of neuroplasticity, in which a specific task-associated neuronal activity triggers mild hypoxia as a local neuron-specific as well as a brain-wide response, comprising indirectly activated neurons and non-neuronal cells.