Papers for the month of Dec '13, Jan '14


"In vivo visuotopic brain mapping with manganese-enhanced MRI and resting-state functional connectivity MRI"
NeuroImage, in-press:in-press

Mouse over here for a brief summary or click to open article in a new tab.Manganese-enhanced MRI and resting-state functional connectivity MRI allowed topographic and layer-specific visual brain mapping to help monitor the neurophysiology of the visual system.


"Development of sensory cortical gamma oscillations and cross-frequency coupling from childhood to early adulthood."
Cerebral Cortex, In press:epub

Mouse over here for a brief summary or click to open article in a new tab.This paper reports on the normal development of cortical gamma oscillations as indexed by steady-state responses to a periodic auditory stimuli.


"Psychophysical definition of S-cone stimuli in the macaque"
Journal of Vision, 13:1

Mouse over here for a brief summary or click to open article in a new tab.We show a method for calibrating individual and location specific S-cone isolating stimuli in macaque monkeys.


"S-cone Visual Stimuli Activate Superior Colliculus Neurons in Old World Monkeys: Implications for Understanding Blindsight"
Journal of Cognitive Neuroscience, in press:in press

Mouse over here for a brief summary or click to open article in a new tab.We show that, contrary to prevailing view, calibrated S-cone isolating stimuli activate superior colliculus neurons in macaque monkeys.


"Monocular Advantage for Face Perception Implicates Subcortical Mechanisms in Adult Humans."
Journal of Cognitive Neuroscience, Epub ahead of print:Epub Ahead of print

Mouse over here for a brief summary or click to open article in a new tab.Most of the work exploring the neural correlates of complex visual skills, such as face perception, has focused on cortical mechanisms. There is, however, substantial phylogenetic and ontogenetic evidence to support the engagement of lower-order structures (for example, subcortical regions) in such tasks. Here, we demonstrate that prestriate regions of cortex (i.e. the monocular portions of the visual pathway) are implicated in face perception, but not in car or word perception, even in adult humans. The representations mediated by these more rudimentary regions are somewhat coarse in nature, relative to cortical representations.


"An altered neural response to reward may contribute to alcohol problems among late adolescents with an evening chronotype."
Psychiatry Research: Neuroimaging, 214:357-64

Mouse over here for a brief summary or click to open article in a new tab.Evening chronotypes not only differ from morning-types in their sleep and circadian timing, but they are prone to problematic outcomes involving reward function, including affective disturbance, sensation seeking, and substance involvement. Using an fMRI monetary reward task, we found that evening chronotypes displayed altered neural responses to reward, which correlated in turn with greater alcohol problems.


"Evidence for cerebellar contributions to adaptive plasticity in speech perception."
Cerebral Cortex, :

Mouse over here for a brief summary or click to open article in a new tab.Human speech perception rapidly adapts to maintain comprehension under adverse listening conditions. For example, with exposure listeners can adapt to heavily accented speech produced by a non-native speaker. Outside the domain of speech perception, adaptive changes in sensory and motor processing have been attributed to cerebellar functions. The present functional magnetic resonance imaging study investigates whether adaptation in speech perception also involves the cerebellum. Acoustic stimuli were distorted using a vocoding plus spectral-shift manipulation and presented in a word recognition task. Regions in the cerebellum that showed differences before versus after adaptation were identified, and the relationship between activity during adaptation and subsequent behavioral improvements was examined. These analyses implicated the right Crus I region of the cerebellum in adaptive changes in speech perception. A functional correlation analysis with the right Crus I as a seed region probed for cerebral cortical regions with covarying hemodynamic responses during the adaptation period. The results provided evidence of a functional network between the cerebellum and language-related regions in the temporal and parietal lobes of the cerebral cortex. Consistent with known cerebellar contributions to sensorimotor adaptation, cerebro-cerebellar interactions may support supervised learning mechanisms that rely on sensory prediction error signals in speech perception.


"Developmental Stages and Sex Differences of White Matter and Behavioral Development through Adolescence: A Longitudinal Diffusion Tensor Imaging (DTI) Study"
NeuroImage, epub ahead of print:epub ahead of print

Mouse over here for a brief summary or click to open article in a new tab.We find hierarchical white matter (WM) development in a longitudinal sample, with adolescent maturation of most frontal connectivity and post-adolescent maturation of corticolimbic connectivity. There were differences by sex and behavior in these patterns; males showed greater and more protracted WM growth, and delayed maturation of WM was associated with poorer cognitive performance.


"MR diffusion histology and micro-tractography reveal mesoscale features of the human cerebellum."
Cerebellum, 12:923

Mouse over here for a brief summary or click to open article in a new tab.Description of mesoscale features of human cerebellum using diffusion-based MRI and microtractography.


"Inflammatory response after spinal cord injury"
Experimental Neurology, 250:151-155

Mouse over here for a brief summary or click to open article in a new tab.The paper reviews inflammation after spinal cord injury and provides a commentary on Blomster at el (2013). Our knowledge of the role of macrophages in spinal cord injury and repair is discussed.


"Biomaterials for spinal cord repair"
Neuroscience Bulletin, 29:445-459

Mouse over here for a brief summary or click to open article in a new tab.The paper provides a comprehansive review of biomaterials that have been employed to support and direct repair of the spinal cord


"A Paired RNAi and RabGAP Overexpression Screen Identifies Rab11 as a Regulator of β-Amyloid Production."
Cell Reports, 5:1536

Mouse over here for a brief summary or click to open article in a new tab.Beta secretase, the enzyme that cleaves APP, needs to cycle along the endocytic pathway in order for it to reach the location in the cells where it can cleave APP to produce A-beta peptides. This paper identifies two key GTPases that regulate part of this cycling, and, therefore, regulate production of A-beta.


"Spatially restricted G protein-coupled receptor activity via divergent endocytic compartments."
J Biol Chem, Epub:Epub

Mouse over here for a brief summary or click to open article in a new tab.Most signaling cascades converge to a handful of second messengers, raising the question of how cells know which receptor the signal is coming from. Here we show that the intracellular location from which receptors signal can define which signaling pathway is activated, suggesting a location-based specificity in signaling.


"Correlations of Behavioral Deficits with Brain Pathology Assessed through Longitudinal MRI and Histopathology in the R6/1 Mouse Model of Huntington's Disease."
PLoS One, 8:12

Mouse over here for a brief summary or click to open article in a new tab.Huntington's disease (HD) is caused by the expansion of a CAG repeat in the huntingtin (HTT) gene. The R6 mouse models of HD express a mutant version of exon 1 HTT and typically develop motor and cognitive impairments, a widespread huntingtin (HTT) aggregate pathology and brain atrophy. Unlike the more commonly used R6/2 mouse line, R6/1 mice have fewer CAG repeats and, subsequently, a less rapid pathological decline. Compared to the R6/2 line, fewer descriptions of the progressive pathologies exhibited by R6/1 mice exist. The association between the molecular and cellular neuropathology with brain atrophy, and with the development of behavioral phenotypes remains poorly understood in many models of HD. In attempt to link these factors in the R6/1 mouse line, we have performed detailed assessments of behavior and of regional brain abnormalities determined through longitudinal, in vivo magnetic resonance imaging (MRI), as well as an end-stage, ex vivo MRI study and histological assessment.


"Comparing visual representations across human fMRI and computational vision."
Journal of Vision, 13:25

Mouse over here for a brief summary or click to open article in a new tab.We explore how well different computer vision recognition models account for neural object encoding across the human cortical visual pathway as measured using fMRI.


"Performance Monitoring in Monkey Frontal Eye-Field"
The Journal of Neuroscience, 34(5):1657-1671

Mouse over here for a brief summary or click to open article in a new tab.The paper describes neural responses in the frontal eye-field related to task difficulty and choice error that emerge immediately after the selection of a response in an oculomotor decision task. These findings suggest a novel role for the frontal eye-fields as part of the neural network that evaluates the preceding choice in order to optimize similar choices in the future.