@article{pmid40331237,

title = {Retinal changes detected by diffuse reflectance spectroscopy in parkinsonian monkeys},

author = {Jonathan Munro and Elahe Parham and Damon DePaoli and Nicolas Lapointe and Cleophace Akitegetse and Shirley Fecteau and Dominic Sauvageau and Thérèse Di Paolo and Daniel C Côté and Martin Parent},

doi = {10.1117/1.NPh.12.2.025008},

issn = {2329-423X},

year  = {2025},

date = {2025-04-01},

journal = {Neurophotonics},

volume = {12},

number = {2},

pages = {025008},

abstract = {SIGNIFICANCE: Parkinson's disease (PD) is diagnosed when 50% neurodegeneration has occurred. The retina could provide biomarkers that would allow for earlier diagnosis. Retinal spectroscopy is a technique that could be used to find such biomarkers.nnAIM: We aimed to find new diagnostic biomarkers for PD following detailed spectral examinations of the retina.nnAPPROACH: The newly developed Zilia Ocular device was used to perform spectrometric scans of the optic nerve head (ONH) and the retina of four cynomolgus monkeys () before and after the administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), a neurotoxin used to produce the gold-standard animal model of PD. From the spectrometric data, the blood oximetry was calculated, and the diffuse reflectance spectra (DRS) were analyzed to find variations between the two experimental conditions. Post-mortem analyses were also performed on the retina of the four parkinsonian monkeys and four additional control animals.nnRESULTS: The analysis of the DRS indicated a lower slope between the 480- and 525-nm wavelengths in both the ONH and the retina. Post-mortem measurements of the retinal layer thicknesses showed that the outer nuclear layer was significantly thinner in MPTP-intoxicated monkeys, compared with controls. Altogether, these results indicate that MPTP altered the optical properties of the ONH and the retina and show that these variations might be explained by MPTP-induced structural changes in the eye fundus, as observed post-mortem.nnCONCLUSIONS: Overall, our results indicate that spectroscopy could be used as a noninvasive method to detect changes in the retina that occur in PD and that such changes could represent retinal biomarkers for improved diagnosis.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid39533953,

title = {Principles and Priorities for Responsible Innovation in Neurotechnology for Canada},

author = {Judy Illes and Susan Boehnke and Jennifer A Chandler and Shirley Fecteau and Pauline Gaprielian and Nir Lipsman and Graeme Moffat and Amy Zarzeczny},

doi = {10.1017/cjn.2024.322},

issn = {0317-1671},

year  = {2024},

date = {2024-11-01},

journal = {Can J Neurol Sci},

pages = {1--4},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid35057668,

title = {Influencing Human Behavior with Noninvasive Brain Stimulation: Direct Human Brain Manipulation Revisited},

author = {Shirley Fecteau},

doi = {10.1177/10738584211067744},

issn = {1089-4098},

year  = {2023},

date = {2023-06-01},

journal = {Neuroscientist},

volume = {29},

number = {3},

pages = {317--331},

abstract = {The use of tools to perturb brain activity can generate important insights into brain physiology and offer valuable therapeutic approaches for brain disorders. Furthermore, the potential of such tools to enhance normal behavior has become increasingly recognized, and this has led to the development of various noninvasive technologies that provides a broader access to the human brain. While providing a brief survey of brain manipulation procedures used in the past decades, this review aims at stimulating an informed discussion on the use of these new technologies to investigate the human. It highlights the importance to revisit the past use of this unique armamentarium and proceed to a detailed analysis of its present state, especially in regard to human behavioral regulation.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid37545594,

title = {Changes in resting-state functional MRI connectivity during and after transcranial direct current stimulation in healthy adults},

author = {Amy E Bouchard and Emmanuelle Renauld and Shirley Fecteau},

doi = {10.3389/fnhum.2023.1229618},

issn = {1662-5161},

year  = {2023},

date = {2023-01-01},

journal = {Front Hum Neurosci},

volume = {17},

pages = {1229618},

abstract = {INTRODUCTION: Transcranial direct current stimulation (tDCS) applied over the dorsolateral prefrontal cortex (DLPFC) at rest can influence behaviors. However, its mechanisms remain poorly understood. This study examined the effect of a single session of tDCS over the bilateral DLPFC on resting-state functional connectivity using fMRI (rs-fcMRI) during and after stimulation in healthy adults. We also investigated whether baseline rs-fcMRI predicted tDCS-induced changes in rs-fcMRI.nnMETHODS: This was a randomized, sham-controlled, double-blind, crossover study. We delivered tDCS for 30 min at 1 mA with the anode and cathode over the left and right DLPFC, respectively. We used seed-based analyses to measure tDCS-induced effects on whole-brain rs-fcMRI using a 3 (before, during, after stimulation) × 2 (active, sham stimulation) ANOVA.nnRESULTS: There were four significant Time × Stimulation interactions on the connectivity scores with the left DLPFC seed (under the anode electrode) and no interactions for the right DLPFC seed (under the cathode electrode). tDCS changed rs-fcMRI between the left DLPFC seed and parieto-occipital, parietal, parieto-occipitotemporal, and frontal clusters during and after stimulation, as compared to sham. Furthermore, rs-fcMRI prior to stimulation predicted some of these tDCS-induced changes in rs-fcMRI during and after stimulation. For instance, rs-fcMRI of the fronto-parietooccipital network predicted changes observed after active stimulation, rs-fcMRI of the fronto-parietal network predicted changes during active stimulation, whereas rs-fcMRI of the fronto-parieto-occipitotemporal and the frontal networks predicted changes both during and after active stimulation.nnDISCUSSION: Our findings reveal that tDCS modulated rs-fcMRI both during and after stimulation mainly in regions distal, but also in those proximal to the area under the anode electrode, which were predicted by rs-fcMRI prior to tDCS. It might be worth considering rs-fcMRI to optimize response to tDCS.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid34791677,

title = {Whole-brain morphometry in Canadian soldiers with posttraumatic stress disorder},

author = {Olivier Roy and Jean Levasseur-Moreau and Emmanuelle Renauld and Luc J Hébert and Jean Leblond and Mathieu Bilodeau and Shirley Fecteau},

doi = {10.1111/nyas.14707},

issn = {1749-6632},

year  = {2022},

date = {2022-03-01},

journal = {Ann N Y Acad Sci},

volume = {1509},

number = {1},

pages = {37--49},

abstract = {Patients with posttraumatic stress disorder (PTSD) display several structural brain differences when compared with healthy individuals. However, findings are particularly inconsistent for soldiers with PTSD. Here, we characterized the brain morphometry of 37 soldiers from the Canadian Armed Forces with adulthood war-related PTSD using structural magnetic resonance imaging. We assessed time since trauma, as well as PTSD, depressive, and anxiety symptoms with the Modified PTSD Symptoms Scale, Beck Depression Inventory, and Beck Anxiety Inventory, respectively. Whole-brain morphometry was extracted with FreeSurfer and compared with a validated normative database of more than 2700 healthy individuals. Volume and thickness from several regions differed from the norms. Frontal regions were smaller and thinner, particularly the superior and rostral middle frontal gyri. Furthermore, smaller left rostral middle frontal gyrus, left pericalcarine cortex, and right fusiform gyrus were associated with more recent trauma. All subcortical structures were bigger, except the hippocampus. These findings suggest a particular brain morphometric signature of PTSD in soldiers. Smaller and thinner frontal and larger subcortical regions support impaired top-down and/or downregulation of emotional response in PTSD. Finally, the correlation of smaller frontal, temporal, and occipital regions with more recent trauma might inform future therapeutic approaches.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid35734582,

title = {Non-invasive brain stimulation and neuroenhancement},

author = {Andrea Antal and Bruce Luber and Anna-Katharine Brem and Marom Bikson and Andre R Brunoni and Roi Cohen Kadosh and Veljko Dubljević and Shirley Fecteau and Florinda Ferreri and Agnes Flöel and Mark Hallett and Roy H Hamilton and Christoph S Herrmann and Michal Lavidor and Collen Loo and Caroline Lustenberger and Sergio Machado and Carlo Miniussi and Vera Moliadze and Michael A Nitsche and Simone Rossi and Paolo M Rossini and Emiliano Santarnecchi and Margitta Seeck and Gregor Thut and Zsolt Turi and Yoshikazu Ugawa and Ganesan Venkatasubramanian and Nicole Wenderoth and Anna Wexler and Ulf Ziemann and Walter Paulus},

doi = {10.1016/j.cnp.2022.05.002},

issn = {2467-981X},

year  = {2022},

date = {2022-01-01},

journal = {Clin Neurophysiol Pract},

volume = {7},

pages = {146--165},

abstract = {Attempts to enhance human memory and learning ability have a long tradition in science. This topic has recently gained substantial attention because of the increasing percentage of older individuals worldwide and the predicted rise of age-associated cognitive decline in brain functions. Transcranial brain stimulation methods, such as transcranial magnetic (TMS) and transcranial electric (tES) stimulation, have been extensively used in an effort to improve cognitive functions in humans. Here we summarize the available data on low-intensity tES for this purpose, in comparison to repetitive TMS and some pharmacological agents, such as caffeine and nicotine. There is no single area in the brain stimulation field in which only positive outcomes have been reported. For self-directed tES devices, how to restrict variability with regard to efficacy is an essential aspect of device design and function. As with any technique, reproducible outcomes depend on the equipment and how well this is matched to the experience and skill of the operator. For self-administered non-invasive brain stimulation, this requires device designs that rigorously incorporate human operator factors. The wide parameter space of non-invasive brain stimulation, including dose (e.g., duration, intensity (current density), number of repetitions), inclusion/exclusion (e.g., subject's age), and homeostatic effects, administration of tasks before and during stimulation, and, most importantly, placebo or nocebo effects, have to be taken into account. The outcomes of stimulation are expected to depend on these parameters and should be strictly controlled. The consensus among experts is that low-intensity tES is safe as long as tested and accepted protocols (including, for example, dose, inclusion/exclusion) are followed and devices are used which follow established engineering risk-management procedures. Devices and protocols that allow stimulation outside these parameters cannot claim to be "safe" where they are applying stimulation beyond that examined in published studies that also investigated potential side effects. Brain stimulation devices marketed for consumer use are distinct from medical devices because they do not make medical claims and are therefore not necessarily subject to the same level of regulation as medical devices (i.e., by government agencies tasked with regulating medical devices). Manufacturers must follow ethical and best practices in marketing tES stimulators, including not misleading users by referencing effects from human trials using devices and protocols not similar to theirs.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid34128386,

title = {Concurrent Transcranial Direct Current Stimulation and Resting-State Functional Magnetic Resonance Imaging in Patients with Gambling Disorder},

author = {Amy E Bouchard and Maya Dickler and Emmanuelle Renauld and Christophe Lenglos and Francine Ferland and Claude Rouillard and Jean Leblond and Shirley Fecteau},

doi = {10.1089/brain.2021.0016},

issn = {2158-0022},

year  = {2021},

date = {2021-12-01},

journal = {Brain Connect},

volume = {11},

number = {10},

pages = {815--821},

abstract = { Transcranial direct current stimulation (tDCS) delivered over the dorsolateral prefrontal cortex (DLPFC) while patients are at rest can decrease craving in patients with substance-related and addictive disorders. Yet, the effects of tDCS on resting-state brain activity remain unknown in this population. This study examined the effects of tDCS on resting-state functional connectivity (rsFC) with concurrent stimulation and functional magnetic resonance imaging in patients with gambling disorder.  This was a randomized, sham-controlled, double-blind, crossover study. The anodal and cathodal electrodes were applied over the right and left DLPFC, respectively. Patients received 30 min of active and sham stimulation on separate days. rsFC was assessed before and during stimulation with seed-based analyses.  There was a significant increase of rsFC between the right DLPFC seed and the right superior parietal lobule during active stimulation as compared to during sham stimulation ( = 0.0059, corrected for multiple comparisons). There was also a positive correlation between rsFC change of this frontoparietal network and brain volume of the right DLPFC ( = 0.0042, corrected for multiple comparisons).  A single session of tDCS targeting the DLPFC strengthened functional connectivity in a frontoparietal circuit, known to be implicated in cognitive control, especially in patients with a greater volume of the region under the anode electrode. Impact statement Transcranial direct current stimulation increased the functional connectivity of a frontoparietal circuit in patients with gambling disorder. These changes were larger in patients with greater volume of the dorsolateral prefrontal cortex. Transcranial direct current stimulation strengthened the connectivity of a brain network known to be associated with cognitive control.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid34175744,

title = {Brain morphometry in adults with gambling disorder},

author = {Amy E Bouchard and Maya Dickler and Emmanuelle Renauld and Christophe Lenglos and Francine Ferland and Claude Rouillard and Jean Leblond and Shirley Fecteau},

doi = {10.1016/j.jpsychires.2021.06.032},

issn = {1879-1379},

year  = {2021},

date = {2021-09-01},

journal = {J Psychiatr Res},

volume = {141},

pages = {66--73},

abstract = {Little is known regarding the brain substrates of Gambling Disorder, including surface brain morphometry, and whether these are linked to the clinical profile. A better understanding of the brain substrates will likely help determine targets to treat patients. Hence, the aim of this study was two-fold, that is to examine surface-based morphometry in 17 patients with gambling disorder as compared to norms of healthy individuals (2713 and 2790 subjects for cortical and subcortical anatomical scans, respectively) and to assess the clinical relevance of morphometry in patients with Gambling Disorder. This study measured brain volume, surface and thickness in Gambling Disorder. We compared these measures to those of a normative database that controlled for factors such as age and sex. We also tested for correlations with gambling-related behaviors, such as gambling severity and duration, impulsivity, and depressive symptoms (assessed using the South Oaks Gambling Screen, years of gambling, Barratt Impulsiveness Scale, and Beck Depression Inventory, respectively). Patients displayed thinner prefrontal and parietal cortices, greater volume and thickness of the occipital and the entorhinal cortices, and greater volume of subcortical regions as compared to the norms of healthy individuals. There were positive correlations between surface area of occipital regions and depressive symptoms. This work contributes to better characterize the brain substrates of Gambling Disorder, which appear to resemble those of substance use disorders and Internet Gaming Disorder.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}