Learn More
The spatial and temporal properties of single neurons were investigated in area 19 of the cat. We evaluated the matching of binocular receptive field properties with regard to the respective strength of the ipsilateral and contralateral inputs. Results indicate that most cells in area 19 are well tuned to spatial and temporal frequencies and exhibit(More)
The spatial and temporal selectivities of single neurons in area 21a of the adult cat were investigated using sinusoidal gratings. Optimal spatial frequencies and visual acuity (high cut-off frequency) were fairly low and spatial bandwidth was mainly narrow. Contrast threshold was generally low but a substantial number of cells were only excited by high(More)
The receptive field properties of single units were assessed in area 21b of the cat visual cortex. Visual cells in this area were binocular and showed relatively large receptive fields. Most cells were strongly sensitive to the direction of drifting gratings. The mean value of the half-widths of the direction tuning curves (32 degrees ) suggests broader(More)
Auditory spatial representations are likely encoded at a population level within human auditory cortices. We investigated learning-induced plasticity of spatial discrimination in healthy subjects using auditory-evoked potentials (AEPs) and electrical neuroimaging analyses. Stimuli were 100 ms white-noise bursts lateralized with varying interaural time(More)
Interaural intensity and time differences (IID and ITD) are two binaural auditory cues for localizing sounds in space. This study investigated the spatio-temporal brain mechanisms for processing and integrating IID and ITD cues in humans. Auditory-evoked potentials were recorded, while subjects passively listened to noise bursts lateralized with IID, ITD or(More)
Electrophysiological recordings were carried out in the callosal recipient zone of area 19 in normal and split-chiasm cats and, for comparison purposes, at the border of areas 17 and 18 of split-chiasm cats. The influences of retinothalamic and callosal inputs on a single cortical neurons were thereby evaluated. Extracellular recordings of single cells were(More)
GABA receptors are ubiquitous in the cerebral cortex and play a major role in shaping responses of cortical neurons. GABA(A) and GABA(B) receptor subunit expression was visualized by immunohistochemistry in human auditory areas from both hemispheres in 9 normal subjects (aged 43-85 years; time between death and fixation 6-24 hours) and in 4 stroke patients(More)
The human primary auditory cortex (AI) is surrounded by several other auditory areas, which can be identified by cyto-, myelo- and chemoarchitectonic criteria. We report here on the pattern of calcium-binding protein immunoreactivity within these areas. The supratemporal regions of four normal human brains (eight hemispheres) were processed histologically,(More)
The human supratemporal plane contains the primary as well as several other auditory areas. We have investigated the intrinsic connectivity of these areas by means of antero- and retrograde labelling with the carbocyanin dye DiI (1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate). A total of 30 injections was placed in both hemispheres of(More)
We investigated how synaptic plasticity is related to the neurodegeneration process in the human dorsolateral prefrontal cortex. Pre- and postsynaptic proteins of Brodmann's area 9 from patients with Alzheimer's disease (AD) and age-matched controls were quantified by immunohistochemical methods and Western blots. The main finding was a significant increase(More)