Cerebral hemodynamic responses to brief periods of neural activity are delayed and dispersed in time. The specific shape of these responses is of some importance to the design and analysis of blood oxygenation level-dependent (BOLD), functional magnetic resonance imaging (fMRI) experiments. Using fMRI scanning, we examine here the characteristics and variability of hemodynamic responses from th...

Visual, auditory, somatosensory, and olfactory stimuli generate temporally precise patterns of action potentials (spikes). It is unclear, however, how the precision of spike generation relates to the pattern and variability of synaptic input elicited by physiological stimuli. We determined how synaptic conductances evoked by light stimuli that activate the rod bipolar pathway control spike gene...

background: central obesity and hyperinsulinaemia of polycystic ovary syndrome (pcos) are associated with chronic sympathetic over activity. objective: to evaluate the autonomic functions and to indicate the superiority, if any, for those functions in the diagnosis of sympathetic over activity in pcos women. materials and methods: sixty-four pcos patients and 40 women served as the control grou...

BACKGROUND Despite increased attention to the role of antenatal maternal psychological stress in postnatal development, remarkably little information is available on the nature of the intrauterine fetal response to maternal psychological state. AIMS To determine whether: (1) the fetus responds to maternal stress; (2) the fetal response changes over gestation; and (3) individual maternal and f...

Previous studies have shown that the receptive field properties, spontaneous activity and spatio-temporal interactions of low-threshold mechanical somatosensory cells in the barrel cortex are influenced by C-fibers. In this study, we examined the effect of C-fiber depletion on response properties of barrel cortex neurons following experience dependent plasticity. Methods: In this study, exte...

previous studies have shown that the receptive field properties, spontaneous activity and spatio-temporal interactions of low-threshold mechanical somatosensory cells in the barrel cortex are influenced by c-fibers. in this study, we examined the effect of c-fiber depletion on response properties of barrel cortex neurons following experience dependent plasticity. methods: in this study, exterac...

Many researchers have investigated the possibility of using auditory evoked potentials (AEPs) to objectively diagnose tinnitus. Published AEP studies suggest differences in neural activity in individuals with tinnitus compared to control groups, but the results are not consistent. There is a great deal of variability seen in auditory evoked- and event-related potentials in the tinnitus populati...

In neuroelectrophysiology one records electric potentials or magnetic fields generated by ensembles of synchronously active neurons in response to externally presented stimuli. These evoked responses are often produced by multiple generators in the presence of ongoing background activity. While source localization techniques or current source density estimation are usually used to identify gene...

Visual Evoked Potentials (VEPs) are evoked potentials generated in response to visual stimuli. The flash VEP (FVEP) is used less frequently than pattern-reversal VEP (PR-VEP) because; it shows great variations in both latency and amplitude in normal subjects. The advantage of FVEP is its feasibility in non-cooperative subjects, which circumvents the major limitation of PR-VEP. The present study...