Search results for "Cortex"
showing 10 items of 1827 documents
Bilaterally recorded multiple-unit activity of the cingulate cortex during head turning conditioning with unilateral medial forebrain bundle stimulat…
1993
Cats were conditioned to turn their heads using a tone conditioned stimulus (CS) and medial forebrain bundle stimulation (MFB) unconditioned stimulus (US). The CS+ was delivered to one ear at a time, in random order, followed by the US. A tone of a different frequency was used as a CS-. The cats learned to respond differentially to the CSs showing head movements of greater acceleration to the CS+ than CS- over sessions. Bilateral recordings of cingulate cortex multiple-unit activity showed increased response amplitudes over sessions and larger responses in the hemisphere ipsilateral to the US. Since ipsilateral multiple-unit responses did not differ for the CSs, the asymmetry was probably d…
LRRK2 is expressed in areas affected by Parkinson's disease in the adult mouse brain.
2006
The leucine-rich repeat kinase 2 (LRRK2) gene was recently found to have multiple mutations that are causative for autosomal dominant inherited Parkinson's disease (PD). Previously, we used Northern blot analysis to show that this gene was expressed in the cerebellum, cerebral cortex, medulla, spinal cord, occipital pole, frontal lobe, temporal lobe and caudate putamen. However, a more comprehensive map of LRRK2 mRNA localization in the central nervous system is still lacking. In this study we have mapped the distribution of the mRNA encoding for LRRK2 using nonradioactive in situ hybridization. We detected a moderate expression of this PD-related gene throughout the adult B2B6 mouse brain.…
Diurnal variation of corticotropin-releasing factor binding sites in the rat brain and pituitary.
1996
1. Corticotropin-releasing factor (CRF) is thought to be involved in the regulation of the diurnal activity of the hypothalamus-pituitary-adrenal (HPA) axis and to act as a neurotransmitter in the brain. To date it is unknown whether the binding sites of the central CRF system are subject to diurnal variations. 2. We measured the number of CRF binding sites over the course of a complete 24-hr light-dark cycle in the pituitary, amygdala, bed nucleus of the stria terminalis (BNST), cingulate cortex, visceral cortex, paraventricular nucleus of the hypothalamus, hippocampus, and locus ceruleus of rats by in vitro receptor autoradiography with iodinated ovine CRF. A 24-hr time course was also es…
Association between cingulum bundle structure and cognitive performance: an observational study in major depression.
2009
AbstractBackgroundMajor depression can be regarded as a systemic neurobehavioral disorder resulting from dysfunction of the limbic-cortical networks. The cingulum bundle represents a major association fiber tract of those networks. The aim of our study was to determine the association of brain structural tissue markers of the cingulum bundle and cognitive function in patients with major depression.MethodsRegion-of-interest-based analyses of the middle-anterior and middle-posterior cingulum bundle fractional anisotropy (FA) and mean diffusivity (MD) using color-coded diffusion-tensor imaging and neuropsychological assessment in 14 patients with major depression.ResultsFA of the middle-anteri…
Asymmetries in classically conditioned head movements and cingulate cortex slow potentials in cats.
1991
Presuming that conditioned head movements in the cat indicate a preference for a specific direction, asymmetries were also expected to be found in bilaterally recorded cingulate cortex slow potentials to a symmetrical tone stimulus during discriminative conditioning. Conditioned stimuli (CS, 1000 and 2500 Hz tones) were delivered through two miniature loudspeakers fitted to the head in front of both ears. The unconditioned stimulus (US) was an electrical stimulation of either the left or right lateral hypothalamus yielding, in addition to its rewarding effects, an unconditioned head turning response (UR) either to the left, right, forwards or upwards. Discrimination learning appeared as mor…
Unilateral medial forebrain bundle activation selectively enhances conditioned orienting head turns and ipsilateral cingulate cortex evoked field res…
1994
Effects of a unilateral medial forebrain bundle (MFB) stimulation unconditioned stimulus (US) on conditioned head turn and bilateral cingulate cortex field potentials were studied in cats. Conditioned stimuli (CSs) of different frequences were given randomly to either ear. The CS+ was followed by the US, and the CS— was presented alone. Before conditioning most cats predominantly turned toward the ear to which the CSs were presented, whereas after conditioning the head turns were in one direction, most prominently contralateral to the US. Negative field potentials were greater in the cingulate cortex ipsilateral to the US than in the cingulate cortex contralateral to the US. Cross correlati…
Tract-specific white matter structural disruption in patients with bipolar disorder
2011
Benedetti F, Absinta M, Rocca MA, Radaelli D, Poletti S, Bernasconi A, Dallaspezia S, Pagani E, Falini A, Copetti M, Colombo C, Comi G, Smeraldi E, Filippi M. Tract-specific white matter structural disruption in patients with bipolar disorder. Bipolar Disord 2011: 13: 414–424. © 2011 The Authors. Journal compilation © 2011 John Wiley & Sons A/S. Objectives: A growing body of evidence suggests that, independent of localized brain lesions, mood disorders can be associated with dysfunction of brain networks involved in the modulation of emotional and cognitive behavior. We used diffusion tensor (DT) tractography to quantify the presence and extent of structural injury to the connections betwe…
Frontocingular Dysfunction in Bulimia Nervosa when Confronted with Disease-specific Stimuli
2011
Objective Bulimia nervosa (BN) is characterized by dysregulation of impulse control, in other words, uncontrolled eating. Functional neuroimaging studies have been sparse and have used variable methodologies. Method Thirteen medication-free female BN patients and 13 female healthy controls were investigated by functional magnetic resonance imaging using a disease-specific food paradigm. Stimuli were rated after the scanning procedure. Results Bulimia nervosa patients showed increased fear ratings and a trend for increased disgust. Magnetic resonance imaging data of 10 BN patients could be analysed. Three BN patients had to be excluded from the analysis because of minimal blood oxygen level …
Aß(25-35) and its C-and/or N-blocked derivatives: copper driven structural features and neurotoxicity
2006
The toxic properties of beta-amyloid protein, Abeta(1-42), the major component of senile plaques in Alzheimer's disease, depend on nucleation-dependent oligomerization and aggregation. In addition, Abeta(1-42) toxicity is favored by the presence of trace metals, which affect the secondary structure of the peptide. A peptide comprising 11 residues within Abeta(1-42) [Abeta(25-35)] aggregates and retains the neurotoxic activity of Abeta(1-42). We have used both Abeta(25-35) and its C-amidated or N-acetylated/C-amidated derivatives to investigate the role of copper(II) in modulating the conformation and aggregation state as well as the neurotoxic properties of amyloid peptides. Electrospray io…
Cellular Mechanisms of Subplate-Driven and Cholinergic Input-Dependent Network Activity in the Neonatal Rat Somatosensory Cortex
2008
Early coordinated network activity promotes the development of cortical structures. Although these early activity patterns have been recently characterized with respect to their developmental, spatial and dynamic properties, the cellular mechanisms by which specific neuronal populations trigger coordinated activity in the neonatal cerebral cortex are still poorly understood. Here we characterize the cellular and molecular processes leading to generation of network activity during early postnatal development. We show that the somatosensory cortex of newborn rats expresses cholinergic-driven calcium transients which are synchronized within the deeply located subplate. Correspondingly, endogen…