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Full-Text Articles in Medicine and Health Sciences

Transcranial Magnetic Stimulation Of The Prefrontal Cortex In Awake Nonhuman Primates Evokes A Polysynaptic Neck Muscle Response That Reflects Oculomotor Activity At The Time Of Stimulation., Chao Gu, Brian D Corneil Oct 2014

Transcranial Magnetic Stimulation Of The Prefrontal Cortex In Awake Nonhuman Primates Evokes A Polysynaptic Neck Muscle Response That Reflects Oculomotor Activity At The Time Of Stimulation., Chao Gu, Brian D Corneil

Brain and Mind Institute Researchers' Publications

Transcranial magnetic stimulation (TMS) has emerged as an important technique in cognitive neuroscience, permitting causal inferences about the contribution of a given brain area to behavior. Despite widespread use, exactly how TMS influences neural activity throughout an interconnected network, and how such influences ultimately change behavior, remain unclear. The oculomotor system of nonhuman primates (NHPs) offers a potential animal model to bridge this gap. Here, based on results suggesting that neck muscle activity provides a sensitive indicator of oculomotor activation, we show that single pulses of TMS over the frontal eye fields (FEFs) in awake NHPs evoked rapid (within ∼25 …


Developmental Stress, Condition, And Birdsong: A Case Study In Song Sparrows., Kim L Schmidt, Elizabeth A Macdougall-Shackleton, Shawn P Kubli, Scott A Macdougall-Shackleton Oct 2014

Developmental Stress, Condition, And Birdsong: A Case Study In Song Sparrows., Kim L Schmidt, Elizabeth A Macdougall-Shackleton, Shawn P Kubli, Scott A Macdougall-Shackleton

Brain and Mind Institute Researchers' Publications

Sexual-selection theory posits that ornaments and displays can reflect a signaler's condition, which in turn is affected both by recent and developmental conditions. Moreover, developmental conditions can induce correlations between sexually selected and other traits if both types of traits exhibit developmental phenotypic plasticity in response to stressors. Thus, sexually selected traits may reflect recent and/or developmental characteristics of signalers. Here, we review data on the relationships between birdsong, a sexually selected trait, and developmental and current condition of birds from a long-term study of a population of song sparrows (Melospiza melodia). Field studies of free-living birds indicate that the …


Annotated Bibliography: Interaction With Animals (1998-2013), Erich Yahner Sep 2014

Annotated Bibliography: Interaction With Animals (1998-2013), Erich Yahner

Erich Yahner, MSLIS

No abstract provided.


Hsisp Annotated Bibliography: Interaction With Animals (1998-2013), Erich Yahner Sep 2014

Hsisp Annotated Bibliography: Interaction With Animals (1998-2013), Erich Yahner

Erich Yahner

No abstract provided.


Sharp Emergence Of Feature-Selective Sustained Activity Along The Dorsal Visual Pathway., Diego Mendoza-Halliday, Santiago Torres, Julio C Martinez-Trujillo Sep 2014

Sharp Emergence Of Feature-Selective Sustained Activity Along The Dorsal Visual Pathway., Diego Mendoza-Halliday, Santiago Torres, Julio C Martinez-Trujillo

Brain and Mind Institute Researchers' Publications

Sustained activity encoding visual working memory representations has been observed in several cortical areas of primates. Where along the visual pathways this activity emerges remains unknown. Here we show in macaques that sustained spiking activity encoding memorized visual motion directions is absent in direction-selective neurons in early visual area middle temporal (MT). However, it is robustly present immediately downstream, in multimodal association area medial superior temporal (MST), as well as and in the lateral prefrontal cortex (LPFC). This sharp emergence of sustained activity along the dorsal visual pathway suggests a functional boundary between early visual areas, which encode sensory inputs, …


Overt Responses During Covert Orienting., Brian D Corneil, Douglas P Munoz Jun 2014

Overt Responses During Covert Orienting., Brian D Corneil, Douglas P Munoz

Brain and Mind Institute Researchers' Publications

A distributed network of cortical and subcortical brain areas controls our oculomotor behavior. This network includes the superior colliculus (SC), which coordinates an ancient visual grasp reflex via outputs that ramify widely within the brainstem and spinal cord, accessing saccadic and other premotor and autonomic circuits. In this Review, we discuss recent results correlating subliminal SC activity in the absence of saccades with diverse components of the visual grasp reflex, including neck and limb muscle recruitment, pupil dilation, and microsaccade propensity. Such subtle manifestations of covert orienting are accessible in the motor periphery and may provide the next generation of …


Gene Co-Citation Networks Associated With Worker Sterility In Honey Bees., Emma Kate Mullen, Mark Daley, Alanna Gabrielle Backx, Graham James Thompson Mar 2014

Gene Co-Citation Networks Associated With Worker Sterility In Honey Bees., Emma Kate Mullen, Mark Daley, Alanna Gabrielle Backx, Graham James Thompson

Brain and Mind Institute Researchers' Publications

BACKGROUND: The evolution of reproductive self-sacrifice is well understood from kin theory, yet our understanding of how actual genes influence the expression of reproductive altruism is only beginning to take shape. As a model in the molecular study of social behaviour, the honey bee Apis mellifera has yielded hundreds of genes associated in their expression with differences in reproductive status of females, including genes directly associated with sterility, yet there has not been an attempt to link these candidates into functional networks that explain how workers regulate sterility in the presence of queen pheromone. In this study we use available …


Attention Deficit Associated With Early Life Interictal Spikes In A Rat Model Is Improved With Acth, Amanda E. Hernan, Abigail Alexander, Pierre-Pascal Lenck-Santini, Rod C. Scott Feb 2014

Attention Deficit Associated With Early Life Interictal Spikes In A Rat Model Is Improved With Acth, Amanda E. Hernan, Abigail Alexander, Pierre-Pascal Lenck-Santini, Rod C. Scott

Dartmouth Scholarship

Children with epilepsy often present with pervasive cognitive and behavioral comorbidities including working memory impairments, attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder. These non-seizure characteristics are severely detrimental to overall quality of life. Some of these children, particularly those with epilepsies classified as Landau-Kleffner Syndrome or continuous spike and wave during sleep, have infrequent seizure activity but frequent focal epileptiform activity. This frequent epileptiform activity is thought to be detrimental to cognitive development; however, it is also possible that these IIS events initiate pathophysiological pathways in the developing brain that may be independently associated with cognitive deficits. These …


Activation Of Mglur2/3 Receptors In The Ventro-Rostral Prefrontal Cortex Reverses Sensorimotor Gating Deficits Induced By Systemic Nmda Receptor Antagonists., Bridget Valsamis, Michael Chang, Marei Typlt, Susanne Schmid Feb 2014

Activation Of Mglur2/3 Receptors In The Ventro-Rostral Prefrontal Cortex Reverses Sensorimotor Gating Deficits Induced By Systemic Nmda Receptor Antagonists., Bridget Valsamis, Michael Chang, Marei Typlt, Susanne Schmid

Brain and Mind Institute Researchers' Publications

Prepulse inhibition (PPI) of acoustic startle is an operational measure of sensorimotor gating, which is disrupted in schizophrenia. NMDA receptor (NMDAR) antagonist induced PPI disruption has become an important pharmacological model for schizophrenia; however, knowledge of the underlying mechanism remains incomplete. This study examines the role of NMDAR in the caudal pontine reticular nucleus (PnC) and the medial prefrontal cortex (mPFC) in NMDARs antagonist induced PPI deficits, as well as the NMDA receptor subtypes involved. We administered the NMDA antagonist MK-801 locally into the caudal pontine reticular formation (PnC), where the PPI mediating pathway converges with the primary startle pathway, …


Bilateral Saccadic Deficits Following Large And Reversible Inactivation Of Unilateral Frontal Eye Field., Tyler R Peel, Kevin Johnston, Stephen G Lomber, Brian D Corneil Jan 2014

Bilateral Saccadic Deficits Following Large And Reversible Inactivation Of Unilateral Frontal Eye Field., Tyler R Peel, Kevin Johnston, Stephen G Lomber, Brian D Corneil

Brain and Mind Institute Researchers' Publications

Inactivation permits direct assessment of the functional contribution of a given brain area to behavior. Previous inactivation studies of the frontal eye field (FEF) have either used large permanent ablations or reversible pharmacological techniques that only inactivate a small volume of tissue. Here we evaluated the impact of large, yet reversible, FEF inactivation on visually guided, delayed, and memory-guided saccades, using cryoloops implanted in the arcuate sulcus. While FEF inactivation produced the expected triad of contralateral saccadic deficits (increased reaction time, decreased accuracy and peak velocity) and performance errors (neglect or misdirected saccades), we also found consistent increases in reaction …


Short-Duration Stimulation Of The Supplementary Eye Fields Perturbs Anti-Saccade Performance While Potentiating Contralateral Head Orienting., Brendan B Chapman, Brian D Corneil Jan 2014

Short-Duration Stimulation Of The Supplementary Eye Fields Perturbs Anti-Saccade Performance While Potentiating Contralateral Head Orienting., Brendan B Chapman, Brian D Corneil

Brain and Mind Institute Researchers' Publications

Many forms of brain stimulation utilize the notion of state dependency, whereby greater influences are observed when a given area is more engaged at the time of stimulation. Here, by delivering intracortical microstimulation (ICMS) to the supplementary eye fields (SEF) of monkeys performing interleaved pro- and anti-saccades, we show a surprising diversity of state-dependent effects of ICMS-SEF. Short-duration ICMS-SEF passed around cue presentation selectively disrupted anti-saccades by increasing reaction times and error rates bilaterally, and also recruited neck muscles, favoring contralateral head turning to a greater degree on anti-saccade trials. These results are consistent with the functional relevance of the …