A5034759974- Neural dynamics and brain function
- Neuroscience and Neuropharmacology Research
- Neuroscience and Music Perception
- Hearing, Cochlea, Tinnitus, Genetics
- Neurological Disorders and Treatments
- Cholinesterase and Neurodegenerative Diseases
- Hearing Loss and Rehabilitation
- Stroke Rehabilitation and Recovery
- Nicotinic Acetylcholine Receptors Study
- Genetic and Clinical Aspects of Sex Determination and Chromosomal Abnormalities
- Ion channel regulation and function
- Biochemical Analysis and Sensing Techniques
- Genetic Syndromes and Imprinting
- Neuroinflammation and Neurodegeneration Mechanisms
- Memory and Neural Mechanisms
- Estrogen and related hormone effects
Montreal Neurological Institute and Hospital
2013-2025
McGill University
2013-2025
Centre hospitalier de l'Université Laval
1999
In both humans and rodents, decline in cognitive function is a hallmark of the aging process; basis for this decrease has yet to be fully characterized. However, using aged rodent models, deficits auditory processing have been associated with significant decreases inhibitory signaling attributed loss GABAergic interneurons. Not only are these interneurons crucial pattern detection other large-scale population dynamics, but they also linked mechanisms mediating plasticity learning, making...
Thyroid hormone (3,5,3′-triiodothyronine; T<sub>3</sub>) is essential for normal development of the vertebrate brain, influencing diverse processes such as neuronal migration, myelin formation, axonal maturation, and dendritic outgrowth. We have identified basic transcription element-binding protein (BTEB), a small GC box-binding protein, T<sub>3</sub>-regulated gene in developing rat brain. BTEB mRNA levels cerebral cortex exhibit developmental regulation thyroid dependence. T<sub>3</sub>...
Abstract During early developmental windows known as critical periods (CPs) of plasticity, passive alterations in the quality and quantity sensory inputs are sufficient to induce profound long-lasting distortions cortical representations. With CP closure, those representations stabilized, a process requiring maturation inhibitory networks maintenance GABAergic tone cortex. In humans rodents, however, inhibition progressively decreases with advancing age, raising possibility that regulation...
We used the rat primary auditory cortex (A1) as a model to probe effects of cholinergic enhancement on perceptual learning and processing mechanisms in both young old animals. Rats learned perform two-tone frequency discrimination task over course two weeks, combined with either administration cholinesterase inhibitor or saline. found that while age groups more quickly through enhancement, did so by improving target detection, whereas inhibiting erroneous responses nontarget stimuli. also...
The prolonged masking of auditory inputs with white noise has been shown to reopen the critical period for spectral tuning in adult rat cortex. Here, we argue that salient temporal particular is responsible changes neuronal activity lead this experience-dependent plasticity. We tested hypothesis by passively exposing rats 2 weeks amplitude-modulated (AM) different modulation depths from 0% (no modulation) 100% (strong modulation). All exposed displayed evidence cortical plasticity as...
ABSTRACT Aging is associated with dysfunction in the cholinergic system, including degeneration of basal forebrain terminals that innervate cortex, which directly contributes to age- and disease-related cognitive decline. In this study, we used [18F]fluoroethoxybenzovesamicol ([18F]FEOBV) positron emission tomography (PET) imaging assess effect age on terminal integrity predefined regions interest its relationship performance healthy older adults who underwent neuropsychological assessment...
Age-related impairments in the primary auditory cortex (A1) include poor tuning selectivity, neural desynchronization, and degraded responses to low-probability or “oddball” sounds. These changes have been for most part attributed reduced inhibition aged brain. Since many of these can be partially reversed with training, it has speculated that they might not purely degenerative but rather represent negative plastic adjustments noisy distorted inputs. To test this hypothesis, we exposed young...
Age-related impairments in the primary auditory cortex (A1) include poor tuning selectivity, neural desynchronization and degraded responses to low-probability or "oddball" sounds. These changes have been for most part attributed reduced inhibition aged brain. Since many of these can be partially reversed with training, it has speculated that they might not purely degenerative but rather represent negative plastic adjustments noisy distorted inputs. To test this hypothesis, we exposed young...
Abstract Parvalbumin-positive (PV+) interneurons are major regulators of adult experience-dependent plasticity. Acute manipulation PV+ cell activity before learning alters the rate acquisition new skills, whereas transient inactivation cells interferes with retrieval previously learned information. However, effects sustained throughout training remain largely unknown. Using chemogenetics in rat auditory cortex during an adaptive sound disrimination task, here we show that exert bidirectional...