Hajszan T, MacLusky NJ, Leranth C. Short-term treatment with the antidepressant fluoxetine triggers pyramidal dendritic spine synapse formation in rat hippocampus. Eur J Neurosci 21: 1299-1303

Department of Obstetrics, Gynaecology and Reproductive Sciences, Yale University School of Medicine, 333 Cedar Street, FMB 312, New Haven, CT 06520-8063, USA.
European Journal of Neuroscience (Impact Factor: 3.18). 04/2005; 21(5):1299-303. DOI: 10.1111/j.1460-9568.2005.03968.x
Source: PubMed


The pathomechanism of major depressive disorder and the neurobiological basis of antidepressant therapy are still largely unknown. It has been proposed that disturbed hippocampal activity could underlie some of the cognitive and vegetative symptoms of depression, at least in part because of loss of pyramidal cell synaptic contacts, a process that is likely to be reversed by antidepressant treatment. Here we provide evidence that daily administration of the antidepressant fluoxetine to ovariectomized female rats for 5 days induces a robust increase in pyramidal cell dendritic spine synapse density in the hippocampal CA1 field, with similar changes appearing in CA3 after 2 weeks of treatment. This rapid synaptic remodelling might represent an early step in the fluoxetine-induced cascade of responses that spread across the entire hippocampal circuitry, leading to the restoration of normal function in the hippocampus. Hippocampal synaptic remodelling might provide a potential mechanism to explain certain aspects of antidepressant therapy and mood disorders, especially those associated with changes in reproductive state in women, that cannot be reconciled adequately with current theories for depression.

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    • "administration increases synaptic density in the hippocampal CA1 pyramidal cell layer, and 14 days of treatment has similar effects in the CA3 pyramidal cell layer [48] . In the olfactory bulbectomy model of depression, chronic treatment with the tricyclic antidepressant amitriptyline blocks the stress-induced decrease in spine density in hippocampal DG, CA1, and CA3 neurons [49] . "
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    Neuroscience Bulletin 02/2015; 31(1):75-86. DOI:10.1007/s12264-014-1484-6 · 2.51 Impact Factor
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    • "Electro Convulsive Therapy ECT is also a known effective antidepressant treatment, and increases plasticity [17]. Neuronal death and brain atrophy are also related to depression, for example in dementia [18]. From the theoretical foundations above, the plastic brain is adaptable in the sense that it reduces free energy by executing its Bayesian function of predicting and adapting to incoming stimuli. "
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    Medical Hypotheses 10/2014; 83(4). DOI:10.1016/j.mehy.2014.07.013 · 1.07 Impact Factor
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    • ") and synaptogenesis (Geinisman et al., 2001; Hajszan et al., 2005). Synapses are sites of cell–cell contacts that transmit electrical or chemical signals in the brain. "
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