Search results for "CORTEX"
showing 10 items of 1827 documents
Effect of acidosis on lipid peroxidation in brain slices.
1991
Acidification of the incubation medium markedly increased lipid peroxidation of cortical brain slices. Lactic acidosis caused a more extensive lipid peroxidation than did phosphoric acidosis (+35% at pH 6 and +81% at pH 5), probably due to the rapid diffusion of the protonated form of lactic acid across cell membranes. These results support the hypothesis that free radical mechanisms may be involved in the cytotoxicity of acidosis.
The sensorimotor and cognitive deficits in rats following 90- and 120-min transient occlusion of the middle cerebral artery
2012
Middle cerebral artery occlusion (MCAO) is the most commonly used method to study the neurological and histological outcomes and the pathological mechanisms of ischaemic stroke. The current work compares sensorimotor and cognitive deficits and the infarct volume in rats following a transient 90- or 120-min MCAO, which allows the appropriate behavioural tests to be chosen based on the goal and design of the experiment. In the beam-walking test, we found significant differences between the 90- and 120-min MCAO groups in the number of foot faults made with the impaired hindlimb on post-stroke days 3, 7 and 14. In the cylinder test, a difference between the 90- and 120-min groups was observed o…
Impaired cortico-bulbar tract function in dysarthria due to hemispheric stroke. Functional testing using transcranial magnetic stimulation.
1997
We investigated cortico-lingual and cortico-orofacial tract function utilizing transcranial magnetic stimulation in 18 consecutive patients with dysarthria due to hemispheric stroke. Delayed responses (conduction time > mean + 2.5 SD of that of 43 controls) or absent responses were considered abnormal. In all patients, motor-cortex stimulation of the lesion side demonstrated absent (13 patients) or delayed (five patients) responses to the tongue bilaterally (17 patients) or unilaterally (one patient). In 14 patients the contralateral orofacial responses were either absent (13 patients) or delayed (one patient). According to the electrophysiological findings, all lesions revealed by CT or MR…
Dopamine acting through D2 receptors modulates the expression of PSA-NCAM, a molecule related to neuronal structural plasticity, in the medial prefro…
2008
A "neuroplastic" hypothesis proposes that changes in neuronal structural plasticity may underlie the aetiology of depression and the action of antidepressants. The medial prefrontal cortex (mPFC) is affected by this disorder and shows an intense expression of the polysialylated form of the neural cell adhesion molecule (PSA-NCAM), a plasticity-associated molecule, which is expressed mainly in interneurons. The monoamines serotonin, dopamine and noradrenaline are the principal targets of antidepressant action. Pharmacological manipulation of serotonin levels regulates synaptophysin and PSA-NCAM expression in the adult mPFC. However, the involvement of structural plasticity on the antidepress…
Chronic Fluoxetine Treatment Increases the Expression of PSA-NCAM in the Medial Prefrontal Cortex
2006
Recent hypotheses suggest that changes in neuronal structure and connectivity may underlie the etiology of depression. The medial prefrontal cortex (mPFC) is affected by depression and shows neuronal remodeling during adulthood. This plasticity may be mediated by the polysialylated form of the neural cell adhesion molecule (PSA-NCAM), which is intensely expressed in the adult mPFC. As the expression of PSA-NCAM is increased by serotonin in other cerebral regions, antidepressants acting on serotonin reuptake may influence PSA-NCAM expression and thus counteract the effects of depression by modulating neuronal structural plasticity. Using immunohistochemistry, we have studied the relationship…
Streptozotocin diabetic mice display depressive-like behavior and alterations in the structure, neurotransmission and plasticity of medial prefrontal…
2015
Diabetes mellitus patients are at increased risk of developing depression, although the neurobiological bases of this comorbidity are not yet fully understood. These patients show CNS alterations, similar to those found in major depression, including changes in the structure and neurotransmission of excitatory neurons. However, although depressive patients and animal models also display alterations in inhibitory networks, little is known about the effects of diabetes on interneurons. Our main objective was to study the impact of diabetes on interneurons of the medial prefrontal cortex (mPFC), one of the regions most affected by major depression. For this purpose we have induced diabetes wit…
Sex differences in renal damage induced in the mouse by Amanita virosa.
1977
Summary The sensitivity of male and female mice to Amanita virosa was compared. Dried, homogenizedmushroom was given orally by stomach tubing at doses of 100, 200, 400 and 800 mg dried mushroom/kg body weight. Both in males and in females, the kidneys were the only organs showing macroscopical changes. The dose of 100 mg/kg caused renal damage in females, whereas in males the first signs of kidney damage were seen at the dose of 400 mg/kg. The renal lesions observed in the males were located in the cortex, while in the females they were limited to the outer stripe of the outer medullary zone. Testectomy diminished the nephrotoxicity of A. virosa in male mice and caused changes in the locali…
Platelet-activating factor contributes to the induction of long-term potentiation in the rat somatosensory cortex in vitro
2007
The contribution of platelet-activating factor (PAF) to the induction of neocortical LTP was examined in rat brain slices containing the primary somatosensory cortex (SI). Field potentials evoked by single pulse stimulation in cortical layer IV were recorded from layer II/III. In control experiments, tetanic high frequency stimulation (HFS) resulted in input-specific, NMDA receptor-dependent LTP (21.1+/-3.2%; mean+/-SEM; n=15; P0.001). BN-52021 (5 microM), an antagonist at the extracellular PAF receptor, weakened the HFS-induced LTP to 12.4+/-2.7% (n=11; P0.05). In contrast, HFS-induced LTP was significantly enhanced to 29.4+/-2.3% (n=11; P0.05) when brain slices were superfused with ACSF c…
Cervical spondylotic myelopathy: Changes of fractional anisotropy in the spinal cord and magnetic resonance spectroscopy of the primary motor cortex …
2019
Abstract Objective To determine the changes in fractional anisotropy (FA) at the proximal spinal cord and in magnetic resonance spectroscopy (MRS) of the precentral gyrus in patients with cervical spondylotic myelopathy (CSM) with respect to clinical symptoms and their duration. Material and Methods 20 patients with CSM (7 female; mean age 64.6 ± 10.5 years) and 18 age/sex matched healthy controls (9 female; mean age 63.5 ± 6.6 years) were prospectively included. Clinical data (modified Japanese Orthopaedic Association Score (mJOA) and Neck Disability Index (NDI)) and 3T MR measurements including DTI at the spinal cord (level C2/3) with FA and MRS of the left and right precentral gyrus were…
Changes in brain oxidative metabolism induced by inhibitory avoidance learning and acute administration of amitriptyline
2007
The effects of antidepressant drugs on memory have been somewhat ignored, having been considered a mere side effect of these compounds. However, the memory impairment caused by several antidepressants could be considered to form part of their therapeutic effects. Amitriptyline is currently one of the most prescribed tricyclic antidepressants, and exerts marked anticholinergic and antihistaminergic effects. In this study, we evaluated the effects of inhibitory avoidance (IA) learning and acute administration of amitriptyline on brain oxidative metabolism. Brain oxidative metabolism was measured in several limbic regions using cytochrome oxidase (CO) quantitative histochemistry. Amitriptyline…