Search results for "NEUROPLASTICITY"
showing 10 items of 136 documents
Role of the amygdala in antidepressant effects on hippocampal cell proliferation and survival and on depression-like behavior in the rat
2021
The stimulation of adult hippocampal neurogenesis by antidepressants has been associated with multiple molecular pathways, but the potential influence exerted by other brain areas has received much less attention. The basolateral complex of the amygdala (BLA), a region involved in anxiety and a site of action of antidepressants, has been implicated in both basal and stress-induced changes in neural plasticity in the dentate gyrus. We investigated here whether the BLA modulates the effects of the SSRI antidepressant fluoxetine on hippocampal cell proliferation and survival in relation to a behavioral index of depression-like behavior (forced swim test). We used a lesion approach targeting th…
Long-term effects on motor cortical excitability induced by repeated muscle vibration during contraction in healthy subjects
2008
article i nfo Objective: The effects of a novel repeated muscle vibration intervention (rMV; 100 Hz, 90 min over 3 consecutive days) on corticomotor excitability were studied in healthy subjects. Methods: rMV was applied over the flexor carpi radialis (FCR) during voluntary contraction (experiment 1), during relaxation and during contraction without vibration (experiment 2). Focal transcranial magnetic stimulation (TMS) was applied before rMV and one hour, and one, two and three weeks after the last muscle vibration intervention. At each of these time points, we assessed the motor map area and volume in the FCR, extensor digitorum communis (EDC) and abductor digiti minimi (ADM). Short-inter…
Memantine blocks sensitization to the rewarding effects of morphine
2009
Knowledge regarding the specific brain changes and neural plasticity processes produced by repeated drug exposure may be used to advance the understanding of the neurobiology of addiction in order to design appropriate medications. In the present study, the influence of N-methyl-d-aspartate (NMDA) glutamatergic receptors on sensitization to the motor and rewarding effects of morphine was evaluated. The effects of pre-exposure to saline or 20 mg/kg morphine plus the NMDA receptor antagonist memantine (10 or 20 mg/kg) on motor activity and place conditioning induced by a low dose of morphine (2 mg/kg) were assessed. The dose of 2 mg/kg of morphine was ineffective in mice pre-exposed to saline…
Memantine presents different effects from MK-801 in motivational and physical signs of morphine withdrawal
2003
Adaptive changes in neural systems due to chronic opiate exposure are related to the neural plasticity phenomenon, NMDA receptors being implicated in these processes, e.g. tolerance, dependence or withdrawal. In this work, we investigated the effect of two non-competitive NMDA antagonists, memantine and MK-801, in motivational (Conditioned Place Aversion paradigm, CPA) and physical aspects of morphine withdrawal. After the induction of morphine dependence, animals in which the CPA was studied, received memantine (5 and 10 mg/kg) or MK-801 (0.3-0.006 mg/kg) either during the acquisition (conditioning) or expression (test) phase of this procedure. Both drugs were capable of inhibiting conditi…
The Polysialylated Form of the Neural Cell Adhesion Molecule (PSA-NCAM) Is Expressed in a Subpopulation of Mature Cortical Interneurons Characterized…
2010
Principal neurons in the adult cerebral cortex undergo synaptic, dendritic, and spine remodeling in response to different stimuli, and several reports have demonstrated that the polysialylated form of the neural cell adhesion molecule (PSA-NCAM) participates in these plastic processes. However, there is only limited information on the expression of this molecule on interneurons and on its role in the structural plasticity of these cells. We have found that PSA-NCAM is expressed in mature interneurons widely distributed in all the extension of the cerebral cortex and have excluded the expression of this molecule in most principal cells. Although PSA-NCAM expression is generally considered a …
Effects of chronic fluoxetine treatment on the rat somatosensory cortex: Activation and induction of neuronal structural plasticity
2009
Recent hypotheses support the idea that disruption of normal neuronal plasticity mechanisms underlies depression and other psychiatric disorders, and that antidepressant treatment may counteract these changes. In a previous report we found that chronic fluoxetine treatment increases the expression of the polysialylated form of the neural cell adhesion molecule (PSA-NCAM), a molecule involved in neuronal structural plasticity, in the somatosensory cortex. In the present study we intended to find whether, in fact, cell activation and neuronal structural remodeling occur in parallel to changes in the expression of this molecule. Using immunohistochemistry, we found that chronic fluoxetine trea…
PSA-NCAM expression in the rat medial prefrontal cortex
2005
The rat medial prefrontal cortex, an area considered homologous to the human prefrontal cortex, is a region in which neuronal structural plasticity has been described during adulthood. Some plastic processes such as neurite outgrowth and synaptogenesis are known to be regulated by the polysialylated form of the neural cell adhesion molecule (PSA-NCAM). Since PSA-NCAM is present in regions of the adult CNS which are undergoing structural remodeling, such as the hypothalamus or the hippocampus, we have analyzed the expression of this molecule in the medial prefrontal cortex of adult rats using immunohistochemistry. PSA-NCAM immunoreactivity was found both in cell bodies and in the neuropil of…
Ipsilateral versus contralateral spontaneous post-stroke neuroplastic changes: involvement of BDNF?
2013
International audience; Stroke is a leading cause of death and disability in industrialized countries. Although surviving patients exhibit a certain degree of restoration of function attributable to brain plasticity, the majority of stroke survivors has to struggle with persisting deficits. In order to potentiate post-stroke recovery, several rehabilitation therapies have been undertaken and many experimental studies have reported that brain-derived neurotrophic factor (BDNF) is central to many facets of neuroplastic processes. However, although BDNF role in brain plasticity is well characterized through strategies that manipulate its content, the involvement of this neurotrophin in spontan…
Fractionating auditory priors: A neural dissociation between active and passive experience of musical sounds
2019
Learning, attention and action play a crucial role in determining how stimulus predictions are formed, stored, and updated. Years-long experience with the specific repertoires of sounds of one or more musical styles is what characterizes professional musicians. Here we contrasted active experience with sounds, namely long-lasting motor practice, theoretical study and engaged listening to the acoustic features characterizing a musical style of choice in professional musicians with mainly passive experience of sounds in laypersons. We hypothesized that long-term active experience of sounds would influence the neural predictions of the stylistic features in professional musicians in a distinct…
Priming the Motor Cortex With Anodal Transcranial Direct Current Stimulation Affects the Acute Inhibitory Corticospinal Responses to Strength Trainin…
2019
Frazer, AK, Howatson, G, Ahtiainen, JP, Avela, J, Rantalainen, T, and Kidgell, DJ. Priming the motor cortex with anodal transcranial direct current stimulation affects the acute inhibitory corticospinal responses to strength training. J Strength Cond Res 33(2): 307-317, 2019-Synaptic plasticity in the motor cortex (M1) is associated with strength training (ST) and can be modified by transcranial direct current stimulation (tDCS). The M1 responses to ST increase when anodal tDCS is applied during training due to gating. An additional approach to improve the M1 responses to ST, which has not been explored, is to use anodal tDCS to prime the M1 before a bout of ST. We examined the priming effe…