Search results for "prefrontal cortex."
showing 10 items of 320 documents
Subthalamic deep brain stimulation improves time perception in Parkinson's disease.
2004
Alterations in temporal estimation have been observed in Parkinson's disease (PD) and have been associated with dopaminergic dysfunction. To investigate whether deep brain stimulation might reverse these abnormalities in PD, patients treated with electrode implantation for subthalamic deep brain stimulation were required to reproduce time intervals in different experimental conditions (off deep brain stimulation/off therapy, on deep brain stimulation/off therapy, on therapy/off deep brain stimulation). Patients treated with deep brain stimulation in off deep brain stimulation/off therapy displayed the anomalous pattern of responses typically observed in PD. When subthalamic deep brain stimu…
Early emergence of deviant frontal fMRI activity for phonological processes in poor beginning readers.
2010
Phonological awareness refers to the ability to perceive and manipulate the sound structure of language and is especially important when children learn to read. Poor phonological awareness is considered the major cause for the emergence of reading difficulties. In this functional magnetic resonance imaging (fMRI) study, we examined the brain correlates of phonological processing in young beginning readers (aged 8.3+/-0.4 y, 2nd grade) with poor (25th percentile) or normal, age-appropriate reading skills (40th percentile) using a covert reading and mental letter substitution task. Letter substitution in words and nonwords induced pronounced activity in a left frontal language network related…
Structural connectivity and subcellular changes after antidepressant doses of ketamine and Ro 25-6981 in the rat: an MRI and immuno-labeling study
2021
© The Author(s) 2021.
Reward for food odors: An fMRI study of liking and wanting as a function of metabolic state and BMI
2014
Brain reward systems mediate liking and wanting for food reward. Here, we explore the differential involvement of the following structures for these two components: the ventral and dorsal striatopallidal area, orbitofrontal cortex (OFC), anterior insula, and anterior cingulate. Twelve healthy female participants were asked to rate pleasantness (liking of food and non-food odors) and the desire to eat (wanting of odor-evoked food) during event-related functional magnetic resonance imaging (fMRI). The subjective ratings and fMRI were performed in hunger and satiety states. Activations of regions-of-interest were compared as a function of task (liking vs. wanting), odor category (food vs. non-…
Memory performance is related to the cortisol awakening response in older people, but not to the diurnal cortisol slope
2015
There are large individual differences in age-related cognitive decline. Hypothalamic-pituitary-adrenal axis (HPA-axis) functioning has been suggested as one of the mechanisms underlying these differences. This study aimed to investigate the relationships between the diurnal cortisol cycle, measured as the cortisol awakening response (CAR), and the diurnal cortisol slope (DCS) and the memory performance of healthy older people. To do so, we assessed the verbal, visual, and working memory performance of 64 participants (32 men) from 57 to 76 years old who also provided 14 saliva samples on two consecutive weekdays to determine their diurnal cortisol cycle. The CAR was linearly and negatively…
Linking personality and brain anatomy: a structural MRI approach to reinforcement sensitivity theory
2019
Reinforcement Sensitivity Theory (RST) proposes a widely used taxonomy of human personality linked to individual differences at both behavioral and neuropsychological levels that describe a predisposition to psychopathology. However, the body of RST research was based on animal findings, and little is known about their anatomical correspondence in humans. Here we set out to investigate MRI structural correlates (i.e. voxel-based morphometry) of the main personality dimensions proposed by the RST in a group of 400 healthy young adults who completed the Sensitivity to Punishment and Sensitivity to Reward Questionnaire (SPSRQ). Sensitivity to punishment scores correlated positively with the gr…
A "double hit" murine model for schizophrenia shows alterations in the structure and neurochemistry of the medial prefrontal cortex and the hippocamp…
2013
Both alterations in neurodevelopment and aversive experiences during childhood and adolescence seem important risk factors for schizophrenia. Animal models reproducing these alterations mimic some of the symptoms, constituting a valid approach to study the etiopathology of this disorder. Among these models, the perinatal injection of N-methyl-d-aspartate receptor antagonists and the postweaning social isolation rearing are among the most widely used. Our aim is to combine them in a "double hit" model, which should produce a wider spectrum of alterations. Lister Hooded rats have been subjected to a single injection of MK-801 at postnatal day 7 and socially isolated from postweaning to adulth…
Fluency and rule breaking behaviour in the frontal cortex
2020
Design (DF) and phonemic fluency tests (FAS; D-KEFS, 2001) are commonly used to investigate voluntary generation. Despite this, several important issues remain poorly investigated. In a sizeable sample of patients with focal left or right frontal lesion we established that voluntary generation performance cannot be accounted for by fluid intelligence. For DF we found patients performed significantly worse than healthy controls (HC) only on the switch condition. However, no significant difference between left and right frontal patients was found. In contrast, left frontal patients were significantly impaired when compared with HC and right frontal patients on FAS. These lateralization findin…
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…
Intermittent cortical stimulation evokes sensitization to cocaine and enduring changes in matrix and striosome neuron responsiveness
2005
Both the behavioral sensitization syndrome and the changes in the responsiveness of striatal neurons evoked by chronic cocaine exposure may be linked to enhanced neocortical activity, yet a direct demonstration of the effects of cortical stimulation on these parameters is lacking. We have found that repeated stimulation of the rat prelimbic cortex with picrotoxin (0.25 microg/0.25 microl, five injections on alternate days followed by 7-day withdrawal) contributed to increase c-Fos protein expression in the striosomes of the dorsolateral striatum, while producing the opposite effect in the matrix compartment, after a single exposure to cocaine (25 mg/kg). Moreover, rats exposed to cortical s…