A5022722122- Neuroscience and Neuropharmacology Research
- Memory and Neural Mechanisms
- Neural dynamics and brain function
- Photoreceptor and optogenetics research
- Sleep and Wakefulness Research
- Neuroinflammation and Neurodegeneration Mechanisms
- Alzheimer's disease research and treatments
- Neuroscience and Neural Engineering
- Ion channel regulation and function
- Stress Responses and Cortisol
- Receptor Mechanisms and Signaling
- Neuroendocrine regulation and behavior
- Nicotinic Acetylcholine Receptors Study
- Tryptophan and brain disorders
- Neurogenesis and neuroplasticity mechanisms
- Olfactory and Sensory Function Studies
- Neurotransmitter Receptor Influence on Behavior
- Electrochemical Analysis and Applications
- Advanced Memory and Neural Computing
- Cholinesterase and Neurodegenerative Diseases
- Mechanical Circulatory Support Devices
- Immune Response and Inflammation
- Cardiac Structural Anomalies and Repair
- Epilepsy research and treatment
- Hemophilia Treatment and Research
McGill University
2015-2024
Douglas Mental Health University Institute
2015-2024
Montreal Neurological Institute and Hospital
2020
University Health Network
2015
University of Toronto
2015
Pinderfields Hospital
2007
Children's Hospital of Western Ontario
1995-2005
Western University
1996-2005
London Health Sciences Centre
2004-2005
Douglas College
2003
Rapid eye movement sleep (REMS) has been linked with spatial and emotional memory consolidation. However, establishing direct causality between neural activity during REMS consolidation proven difficult because of the transient nature significant caveats associated deprivation techniques. In mice, we optogenetically silenced medial septum γ-aminobutyric acid-releasing (MS(GABA)) neurons, allowing for temporally precise attenuation memory-associated theta rhythm without disturbing sleeping...
Aims Phosphorylation, conformational changes and cleavage of tau protein have been widely suggested to contribute abnormal processing in the pathogenesis A lzheimer's disease, as well other tauopathies. Consistently, many phosphorylated sites, such Ser 199–202 – Thr 205 396–404 , associated with this pathological processing. The present study examined chronological appearance phosphorylation during neurofibrillary tangle ( NFT ) evolution lzheimer disease AD D own syndrome. Methods...
Abstract Alzheimer's disease ( AD ) is an age‐related neurodegenerative disorder characterized by memory impairments. Brain oscillatory activity critical for cognitive function and altered in patients. Recent evidence suggests that accumulation of soluble amyloid‐beta A β) induces reorganization hippocampal networks. However, whether fine changes network might be present at very early stages, before β overproduction, remains to determined. We therefore assessed theta gamma oscillations their...
Slow gamma oscillations (30-60 Hz) correlate with retrieval of spatial memory. Altered slow have been observed in Alzheimer's disease. Here, we use the J20-APP AD mouse model that displays memory loss as well reduced amplitude and phase-amplitude coupling to theta phase. To restore hippocampus, used optogenetics activate medial septal parvalbumin neurons at different frequencies. We show optogenetic stimulation 40 Hz (but not 80 restores hippocampal amplitude, J20 model. Restoration during...
The medial septum-diagonal band complex (MSDB) contains cholinergic and non-cholinergic neurons known to play key roles in learning memory processing, the generation of hippocampal theta rhythm. Electrophysiologically, several classes have been described MSDB, but their chemical identity remains be fully established. By combining electrophysiology with single-cell RT-PCR, we identified four MSDB vitro. first class displayed slow-firing little or no Ih, expressed choline acetyl-transferase...
The medial septum and diagonal band of Broca (MS-DBB) has an essential role for theta rhythm generation in the hippocampus is critical learning memory. MS-DBB contains cholinergic, GABAergic, recently described glutamatergic neurons, but their specific contribution to poorly understood. Here, we examined neurons using optogenetic activation electrophysiological recordings performed vitro preparations freely behaving mice. experiments slices suggest that provide prominent excitatory inputs a...
Neurons of the medial septum and diagonal band Broca (MS-DBB) provide an important input to hippocampus are critically involved in learning memory. Although cholinergic GABAergic MS-DBB neurons known modulate hippocampal activity, role recently described glutamatergic is unknown. Here, we examined electrophysiological properties tested whether they a functional synaptic hippocampus. To visualize neurons, used slices from transgenic mice which green fluorescent protein expressed specifically...
Seizures in temporal lobe epilepsy can be classified as hypersynchronous and low-voltage fast according to their onset patterns. Experimental evidence suggests that fast-onset seizures mainly result from the synchronous activity of γ-aminobutyric acid-releasing cells. In this study, we tested hypothesis using optogenetic control parvalbumin-positive interneurons entorhinal cortex, vitro 4-aminopyridine model. We found both spontaneous optogenetically induced had similar addition, types...
Objective Ictal events occurring in temporal lobe epilepsy patients and experimental models mimicking this neurological disorder can be classified, based on their onset pattern, into low‐voltage, fast versus hypersynchronous seizures. It has been suggested that the pattern is mainly contributed by interneuronal (γ‐aminobutyric acidergic) signaling, whereas involves activation of principal (glutamatergic) cells. Methods Here, we tested hypothesis using optogenetic control parvalbumin‐positive...
Abstract Dopamine neurons have been suggested to use glutamate as a cotransmitter. To identify the basis of such phenotype, we examined expression three recently identified vesicular transporters (VGLUT1‐3) in postnatal rat dopamine culture. We found that majority isolated express VGLUT2, but not VGLUT1 or 3. In comparison, serotonin only VGLUT3. Single‐cell RT‐PCR experiments confirmed presence VGLUT2 mRNA neurons. Arguing for phenotypic heterogeneity among axon terminals, find proportion...
The chemokine IL‐8 is known to be synthesized by glial cells in the brain. It has traditionally been shown have an important role neuroinflammation but recent evidence indicates that it may also involved rapid signaling neurons. We investigated how participates neuronal using a combination of whole‐cell recording and single‐cell RT‐PCR on dissociated rat septal show can acutely reduce Ca 2+ currents neurons, effect was concentration‐dependent, closure L‐ N‐type channels, activation G iα1...
The medial septum and diagonal band complex (MS/DB) is important for learning memory known to contain cholinergic GABAergic neurones. Glutamatergic neurones have also been recently described in this area but their function remains unknown. Here we show that local glutamatergic can be activated using 4‐aminopyridine (4‐AP) the GABA A receptor antagonist bicuculline regular MS/DB slices, or mini‐MS/DB slices. spontaneous responses were mediated by AMPA receptors and, a lesser extend, NMDA...
Gamma rhythms are essential for memory encoding and retrieval. Despite extensive study of these in the entorhinal cortex, dentate gyrus, CA3, CA1, almost nothing is known regarding their generation organization structure delivering most prominent hippocampal output: subiculum. Here we show using a complete rat preparation vitro that subiculum intrinsically independently generates spontaneous slow (25–50 Hz) fast (100–150 gamma during rising phase peak persistent subicular theta rhythms....
Mesencephalic dopamine (DA) neurons have been suggested to use glutamate as a cotransmitter. Here, we suggest mechanism for this form of cotransmission by showing that subset DA both in vitro and vivo expresses vesicular transporter 2 (VGluT2). Expression VGluT2 decreases with age. Moreover, when are grown isolation using microculture system, there is marked upregulation expression. We provide evidence expression normally repressed through contact-dependent interaction GABA other neurons,...
The medial septum diagonal band area (MS/DB) projects to the hippocampus through fornix/fimbria pathway and is implicated in generating hippocampal theta oscillations. also back MS/DB, but very little known functionally about this input. Here, we investigated physiological role of hippocamposeptal feedback MS/DB a complete vitro septohippocampal preparation containing intact interconnecting pathway. We demonstrated that carbachol-induced rhythmic theta-like oscillations recorded...