BACKGROUND: The dopamine transporter (DAT) is known to be a key regulator of dopamine, and recent studies of genetics, treatment, and imaging have highlighted the role of DAT in attention-deficit/hyperactivity disorder (ADHD). The findings of in vivo neuroimaging of DAT in ADHD have been somewhat discrepant, however.
The present study combined measures of regional cerebral blood flow (rCBF) using positron emission tomography (PET) with measures of the autonomic nervous system using skin conductance (SC), heart rate (HR), and the high frequency band of heart rate variability (HRV) in ten healthy participants who were exposed to autobiographical scripts of memories for three target emotions: anger, happiness, and sadness.
This is the first report to demonstrate quantitative monitoring of infant brain development with frequency-domain near-infrared spectroscopy (FD-NIRS). Regionally specific increases in blood volume and oxygen consumption were measured in healthy infants during their first year. The results agree with prior PET and SPECT reports; but, unlike these methods, FD-NIRS is portable and uses nonionizing radiation.
OBJECTIVE: The abuse potential of methylphenidate has been related to the drug's capacity to produce a rapid onset of blockade of the presynaptic dopamine transporter in the brain. An oral once-a-day osmotic controlled-release formulation of methylphenidate produces a more gradual rise in plasma methylphenidate concentration, compared with immediate-release methylphenidate.
Alzheimer's disease (AD) is characterized by the presence of aggregates of the amyloid-beta (A beta) peptide in the brain. These aggregates manifest themselves as senile plaques and cerebrovascular amyloid angiopathy (CAA). While traditional histochemical approaches can easily identify these deposits in postmortem tissue, only recently have specific ligands been developed to target A beta in living patients using positron emission tomography (PET).
Using positron emission tomography we explored brain regions activated during the perception of face expressions, emotional voices and combined audio-visual pairs. A convergence region situated in the left lateral temporal cortex was more activated by bimodal stimuli than by either visual only or auditory only stimuli.
Positron emission tomography (PET) is a noninvasive imaging method used to obtain quantitative molecular and biochemical information about physiological processes in the body. In other words, PET imaging can show the chemical functioning of organs and tissues in the living object. The concept of positron emission imaging was already developed in 1951 and the first human studies were published in 1953.
