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Ulrich M, Pollali E, Çalışkan G, Stork O, Albrecht A. Sex differences in anxiety and threat avoidance in GAD65 knock-out mice. Neurobiol Dis 2023; 183:106165. [PMID: 37230180 DOI: 10.1016/j.nbd.2023.106165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 04/27/2023] [Accepted: 05/03/2023] [Indexed: 05/27/2023] Open
Abstract
Anxiety disorders have been linked to a disbalance of excitation and inhibition in a network of brain structures comprising frontal cortical regions, the amygdala and the hippocampus, among others. Recent imaging studies suggest sex differences in the activation of this anxiety network during the processing of emotional information. Rodent models with genetically altered ϒ-amino butyric acid (GABA) neurotransmission allow studying the neuronal basis of such activation shifts and their relation to anxiety endophenotypes, but to date sex effects have rarely been addressed. Using mice with a null mutation of the GABA synthetizing enzyme glutamate decarboxylase 65 (GAD65-/-), we started to compare anxiety-like behavior and avoidance in male vs. female GAD65-/- mice and their wildtype littermates. In an open field, female GAD65-/- mice displayed increased activity, while male GAD65-/- mice showed an increased adaptation of anxiety-like behavior over time. GAD65-/- mice of both sexes had a higher preference for social interaction partners, which was further heightened in male mice. In male mice higher escape responses were observed during an active avoidance task. Together, female mice showed more stable emotional responses despite GAD65 deficiency. To gain insights into interneuron function in network structures controlling anxiety and threat perception, fast oscillations (10-45 Hz) were measured in ex vivo slice preparations of the anterior cingulate cortex (ACC). GAD65-/- mice of both sexes displayed increased gamma power in the ACC and a higher density of PV-positive interneurons, which are crucial for generating such rhythmic activity. In addition, GAD65-/- mice had lower numbers of somatostatin-positive interneurons in the basolateral amygdala and in the dorsal dentate gyrus especially in male mice, two key regions important for anxiety and active avoidance responses. Our data suggest sex differences in the configuration of GABAergic interneurons in a cortico-amygdala-hippocampal network controlling network activity patterns, anxiety and threat avoidance behavior.
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Affiliation(s)
- Michelle Ulrich
- Institute of Anatomy, Otto-von-Guericke-University, Leipziger Str. 44, 39120 Magdeburg, Germany.
| | - Evangelia Pollali
- Institute of Biology, Otto-von-Guericke-University, Leipziger Str. 44, 39120 Magdeburg, Germany; Center for Behavioral Brain Sciences (CBBS), Universitätsplatz 2, 39106 Magdeburg, Germany.
| | - Gürsel Çalışkan
- Institute of Biology, Otto-von-Guericke-University, Leipziger Str. 44, 39120 Magdeburg, Germany; Center for Behavioral Brain Sciences (CBBS), Universitätsplatz 2, 39106 Magdeburg, Germany; Research Group "Synapto-Oscillopathies", Institute of Biology, Otto-von-Guericke-University, Magdeburg, Germany.
| | - Oliver Stork
- Institute of Biology, Otto-von-Guericke-University, Leipziger Str. 44, 39120 Magdeburg, Germany; Center for Behavioral Brain Sciences (CBBS), Universitätsplatz 2, 39106 Magdeburg, Germany; Center for Intervention and Research on adaptive and maladaptive brain Circuits underlying mental health (C-I-R-C), Jena-Magdeburg-Halle, Germany.
| | - Anne Albrecht
- Institute of Anatomy, Otto-von-Guericke-University, Leipziger Str. 44, 39120 Magdeburg, Germany; Center for Behavioral Brain Sciences (CBBS), Universitätsplatz 2, 39106 Magdeburg, Germany; Center for Intervention and Research on adaptive and maladaptive brain Circuits underlying mental health (C-I-R-C), Jena-Magdeburg-Halle, Germany.
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Sandhu KV, Demiray YE, Yanagawa Y, Stork O. Dietary phytoestrogens modulate aggression and activity in social behavior circuits of male mice. Horm Behav 2020; 119:104637. [PMID: 31783026 DOI: 10.1016/j.yhbeh.2019.104637] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 11/06/2019] [Accepted: 11/10/2019] [Indexed: 01/02/2023]
Abstract
Phytoestrogens comprise biologically active constituents of human and animal diet that can impact on systemic and local estrogen functions in the brain. Here we report on the importance of dietary phytoestrogens for maintaining activity in a brain circuit controlling aggressive and social behavior of male mice. After six weeks of low-phytoestrogen chronic diet (diadzein plus genistein <20 μg/g) a reduction of intermale aggression and altered territorial marking behavior could be observed, compared to littermates on a standard soy-bean based diet (300 μg/g). Further, mice on low-phyto diet displayed a decrease in sociability and a reduced preference for social odors, indicating a general disturbance of social behavior. Underlying circuits were investigated by analysing the induction of the activity marker c-Fos upon social encounter. Low-phyto diet led to a markedly reduced c-Fos induction in the medial as well as the cortical amygdala, the lateral septum, medial preoptic area and bed nucleus of the stria terminalis. No difference between groups was observed in the olfactory bulb. Together our data suggest that dietary phytoestrogens critically modulate social behavior circuits in the male mouse brain.
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Affiliation(s)
- Kiran Veer Sandhu
- Department of Genetics & Molecular Neurobiology, Institute of Biology, Otto-von-Guericke University Magdeburg, 39120 Magdeburg, Germany
| | - Yunus Emre Demiray
- Department of Genetics & Molecular Neurobiology, Institute of Biology, Otto-von-Guericke University Magdeburg, 39120 Magdeburg, Germany
| | - Yuchio Yanagawa
- Department of Genetic and Behavioural Neuroscience, Gunma University Graduate School of Medicine and JST, CREST, Maebashi 371-8511, Japan
| | - Oliver Stork
- Department of Genetics & Molecular Neurobiology, Institute of Biology, Otto-von-Guericke University Magdeburg, 39120 Magdeburg, Germany; Center for Behavioural Brain Sciences, Magdeburg, 39120 Magdeburg, Germany.
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Çalışkan G, Raza SA, Demiray YE, Kul E, Sandhu KV, Stork O. Depletion of dietary phytoestrogens reduces hippocampal plasticity and contextual fear memory stability in adult male mouse. Nutr Neurosci 2019; 24:951-962. [PMID: 31814540 DOI: 10.1080/1028415x.2019.1698826] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Introduction: Phytoestrogens are non-steroidal estrogen analogues and are found primarily in soy products. They have received increasing attention as dietary supplements for estrogen deficiency and as modulators of endogenous estrogen functions, including cognition and emotion. In addition to modifying the levels of circulating sex hormones, phytoestrogens also exert direct effects on estrogen and androgen receptors in the brain and thus effectively modulate the neural circuit functions.Objective: The aim of this study was to investigate the long-term effects of low phytoestrogen intake (∼6 weeks) on the hippocampal plasticity and hippocampus-dependent memory formation in the adult C57BL/6 male mice.Methods and Results: In comparison to mice on a diet with normal phytoestrogen content, mice on low phytoestrogen diet showed a significant reduction in the phosphorylation of NR2B subunit, a molecular correlate of plasticity in the Schaffer collateral-CA1 synapse. We observed a profound decrease in long-term potentiation (LTP) in the ventral hippocampus, whereas no effect on plasticity was evident in its dorsal portion. Furthermore, we demonstrated that acute perfusion of slices with an estrogen analogue equol, an isoflovane metabolized from daidzein produced by the bacterial flora in the gut, was able to rescue the observed LTP deficit. Examining potential behavioral correlates of the plasticity attenuation, we found that mice on phytoestrogen-free diet display decreased contextual fear memory at remote but not at recent time points after training.Conclusions: Our data suggests that nutritional phytoestrogens have profound effects on the plasticity in the ventral hippocampus and ventral hippocampus-dependent memory.
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Affiliation(s)
- Gürsel Çalışkan
- Institute of Biology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany.,Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
| | - Syed Ahsan Raza
- Institute of Biology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany.,Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
| | - Yunus E Demiray
- Institute of Biology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Emre Kul
- Institute of Biology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Kiran V Sandhu
- Institute of Biology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany.,APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Oliver Stork
- Institute of Biology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany.,Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
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Melzer N, Budde T, Stork O, Meuth SG. Limbic Encephalitis: Potential Impact of Adaptive Autoimmune Inflammation on Neuronal Circuits of the Amygdala. Front Neurol 2015; 6:171. [PMID: 26284026 PMCID: PMC4522870 DOI: 10.3389/fneur.2015.00171] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 07/20/2015] [Indexed: 12/31/2022] Open
Abstract
Limbic encephalitis is characterized by adaptive autoimmune inflammation of the gray matter structures of the limbic system. It has recently been identified as a major cause of temporal lobe epilepsy accompanied by progressive declarative – mainly episodic – memory disturbance as well as a variety of rather poorly defined emotional and behavioral changes. While autoimmune inflammation of the hippocampus is likely to be responsible for declarative memory disturbance, consequences of autoimmune inflammation of the amygdala are largely unknown. The amygdala is central for the generation of adequate homoeostatic behavioral responses to emotionally significant external stimuli following processing in a variety of parallel neuronal circuits. Here, we hypothesize that adaptive cellular and humoral autoimmunity may target and modulate distinct inhibitory or excitatory neuronal networks within the amygdala, and thereby strongly impact processing of emotional stimuli and corresponding behavioral responses. This may explain some of the rather poorly understood neuropsychiatric symptoms in limbic encephalitis.
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Affiliation(s)
- Nico Melzer
- Department of Neurology, University of Münster , Münster , Germany
| | - Thomas Budde
- Institute of Physiology I, University of Münster , Münster , Germany
| | - Oliver Stork
- Department of Genetics and Molecular Neurobiology, Institute of Biology, Otto-von-Guericke University Magdeburg , Magdeburg , Germany
| | - Sven G Meuth
- Department of Neurology, University of Münster , Münster , Germany ; Department of Neuropathophysiology, Institute of Physiology I, University of Münster , Münster , Germany
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