Open Access. Powered by Scholars. Published by Universities.®

Neurosciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 5 of 5

Full-Text Articles in Neurosciences

Direct Demonstration Of Retroviral Recombination In A Rhesus Monkey, Dawn P. Wooley, Randall A. Smith, Susan Czajak, Ronald C. Desrosiers Dec 1997

Direct Demonstration Of Retroviral Recombination In A Rhesus Monkey, Dawn P. Wooley, Randall A. Smith, Susan Czajak, Ronald C. Desrosiers

Neuroscience, Cell Biology & Physiology Faculty Publications

Recombination may be an important mechanism for increasing variation in retroviral populations. Retroviral recombination has been demonstrated in tissue culture systems by artificially creating doubly infected cells. Evidence for retroviral recombination in vivo is indirect and is based principally on the identification of apparently mosaic human immunodeficiency virus type 1 genomes from phylogenetic analyses of viral sequences. We infected a rhesus monkey with two different molecularly cloned strains of simian immunodeficiency virus. One strain of virus had a deletion in vpx and vpr, and the other strain had a deletion in nef. Each strain on its own induced low virus …


Neurobehavior In Preterm Neonates Exposed To Cocaine, Alcohol, And Tobacco, K. A. Espy, M. L. Riese, D. J. Francis Nov 1997

Neurobehavior In Preterm Neonates Exposed To Cocaine, Alcohol, And Tobacco, K. A. Espy, M. L. Riese, D. J. Francis

Developmental Cognitive Neuroscience Laboratory: Faculty and Staff Publications

Neonatal neurobehavioral development was investigated in a sample of 20 hospitalized, prenatally cocaine-exposed preterm infants and 20 matched non-exposed controls. Prenatal cocaine exposure was related to reductions in attention performance that remained apparent at 36 wks conceptional age. There was no impact of prenatal cocaine exposure on the rate of change in attention proficiency. In utero alcohol exposure was associated with increased rates of age-related change in motor skill. Alcohol-related performance deficits were transient; alcohol-exposed infants reached an equivalent level of motor performance exhibited by the non-exposed infants by 36 wks conceptional age. These findings highlight the importance of considering …


The Shape School: Assessing Executive Function In Preschool Children, K. A. Espy Nov 1997

The Shape School: Assessing Executive Function In Preschool Children, K. A. Espy

Developmental Cognitive Neuroscience Laboratory: Faculty and Staff Publications

Age-related changes in executive function were examined on a new task, the Shape School, in 70 preschool children (32-68 months old). The Shape School is a colorful storybook designed to examine inhibition and switching processes in young children. Results confirmed that task efficiency varied significantly with age, with older age groups outperforming younger groups. Furthermore, inhibition efficiency improved significantly between 3 to 4 years of age, whereas switching skills showed developmental improvement from 4 to 5 years of age. These results suggest that the Shape School is sensitive to maturational effects and that performance can be parsed into inhibition and …


Triple Dissociation Of Anterior Cingulate, Posterior Cingulate, And Medial Frontal Cortices On Visual Discrimination Tasks Using A Touchscreen Testing Procedure For The Rat., T J Bussey, J L Muir, B J Everitt, T W Robbins Oct 1997

Triple Dissociation Of Anterior Cingulate, Posterior Cingulate, And Medial Frontal Cortices On Visual Discrimination Tasks Using A Touchscreen Testing Procedure For The Rat., T J Bussey, J L Muir, B J Everitt, T W Robbins

Brain and Mind Institute Researchers' Publications

Four experiments examined effects of quinolinic acid-induced lesions of the anterior cingulate, posterior cingulate, and medial frontal cortices on tests of visual discrimination learning, using a new "touchscreen" testing method for rats. Anterior cingulate cortex lesions impaired acquisition of an 8-pair concurrent discrimination task, whereas posterior cingulate cortex lesions facilitated learning but selectively impaired the late stages of acquisition of a visuospatial conditional discrimination. Medial frontal cortex lesions selectively impaired reversal learning when stimuli were difficult to discriminate; lesions of anterior and posterior cingulate cortex had no effect. These results suggest roles for the anterior cingulate, posterior cingulate, and medial …


Transcranial Magnetic Stimulation Of The Prefrontal Cortex Delays Contralateral Endogenous Saccades, Tony Ro, Avishai Henik, Liana Machado, Robert D. Rafal Jul 1997

Transcranial Magnetic Stimulation Of The Prefrontal Cortex Delays Contralateral Endogenous Saccades, Tony Ro, Avishai Henik, Liana Machado, Robert D. Rafal

Publications and Research

The contributions of the superior prefrontal cortex (SPFC) and the superior parietal lobule (SPL) in generating voluntary endogenous and reflexive visually guided saccades were investigated using transcranial magnetic stimulation (TMS). Subjects made choice saccades to the left or right visual field in response to a central arrowhead (endogenous go signal) or a peripheral asterisk (exogenous go signal) that were presented along with a single TMS pulse at varying temporal intervals. TMS over the SPFC increased latencies for saccades made in response to an endogenous go signal toward the contralateral hemifield. No effects were observed when the go signal was exogenous …