UNLABELLED: PET and (11)C-raclopride have been used to assess dopamine activity in vivo using a paradigm that involved d-amphetamine (AMPH)-induced endogenous dopamine release that led to reductions (relative to baseline) in the (11)C-raclopride-specific binding parameter (binding potential). A common assumption in bolus injection PET studies of this type is that cerebral blood flow (CBF) does not vary during the scan. The goal of this work was to examine the effect of AMPH administration on sequential PET measures of CBF.
Mathematical co-registration of functional image data (e.g., positron emission tomography, PET) to anatomical magnetic resonance (MR) imaging data allows for objective associations between function and anatomy. Baboons are often used as non-human primate models for functional neuroimaging studies. In this work, a digital MR-based high-resolution atlas of the baboon brain was generated and evaluated for PET.
BACKGROUND: Several lines of evidence support the possibility that disturbances of dopamine (DA) function could contribute to alterations of weight, feeding, motor activity, and reward in anorexia nervosa (AN).
METHODS: To assess possibly trait-related disturbances but avoid confounding effects of malnutrition, 10 women who were recovered from AN (REC AN) were compared with 12 healthy control women (CW). Positron emission tomography with [(11)C]raclopride was used to assess DA D2/D3 receptor binding.
BACKGROUND: Many studies have found disturbances of serotonin (5-HT) activity in anorexia nervosa (AN). Because little is known about 5-HT receptor function in AN, positron emission tomography (PET) imaging with 5-HT receptor-specific radioligands was used to characterize 5-HT1A and 5-HT2A receptors.
RATIONALE: Several lines of evidence suggest that altered serotonin (5-HT) function persists after recovery from anorexia nervosa (AN) and bulimia nervosa (BN).
OBJECTIVES: We compared 11 subjects who recovered (>1 year normal weight, regular menstrual cycles, no binging or purging) from restricting-type AN (REC RAN), 7 who recovered from bulimia-type AN (REC BAN), 9 who recovered from BN (REC BN), and 10 healthy control women (CW).
OBJECTIVE: Abnormalities of regional cerebral blood flow (rCBF) have been found in individuals who are ill with anorexia (AN) or bulimia nervosa (BN). Little is known about whether rCBF normalizes after recovery from AN and BN.
METHOD: Eighteen control women (CW), 10 recovered restricting type AN, 8 recovered AN with a binging history, and 9 recovered BN participants without a history of AN were studied using positron emission tomography and [(15)O]water in order to assess rCBF.
The positron emission tomography (PET) radiotracer Pittsburgh Compound-B (PiB) binds with high affinity to beta-pleated sheet aggregates of the amyloid-beta (Abeta) peptide in vitro. The in vivo retention of PiB in brains of people with Alzheimer's disease shows a regional distribution that is very similar to distribution of Abeta deposits observed post-mortem.
We evaluated the region-to-region correlation, laterality and asymmetry of amyloid deposition in subjects with mild cognitive impairment (MCI) or Alzheimer's disease (AD) using the amyloid tracer, Pittsburgh Compound B (PiB). Seventeen subjects, including 7 with MCI (MMSE 26.7+/-2.4) and 10 with AD (MMSE of 24.8+/-2.7) underwent PiB imaging. Measures of laterality (i.e., group-wise predilection for right or left) and asymmetry (i.e., group-wise predilection for unequal PiB retention between the two hemispheres) were calculated for 17 Regions of Interest (ROIs).
There is increasing evidence for an empiric link between late-life depression and Alzheimer disease (AD). The neuropathology of AD, previously only confirmed at autopsy, may now be detectable in vivo using selective imaging ligands for beta-amyloid. Positron emission tomography (PET) with [11C] 6-OH-BTA-1 [Pittsburgh Compound-B (PiB)] has shown high tracer retention in cortical areas in patients with clinical diagnoses of probable AD and low retention in age-matched controls. We also previously reported variable PiB retention in patients with mild cognitive impairment (MCI).
Accumulating evidence indicates that synchronization of cortical neuronal activity at gamma-band frequencies is important for various types of perceptual and cognitive processes and that GABA-A receptor-mediated transmission is required for the induction of these network oscillations. In turn, the abnormalities in GABA transmission postulated to play a role in psychiatric conditions such as schizophrenia might contribute to the cognitive deficits seen in this illness.
