Quantitative pharmacologic MRI in mice.

Pharmacologic MRI (phMRI) uses functional MRI techniques to provide a noninvasive in vivo measurement of the hemodynamic effects of drugs. The cerebral blood volume change (ΔCBV) serves as a surrogate for neuronal activity via neurovascular coupling mechanisms. By assessing the location and time course of brain activity in mouse mutant studies, phMRI can provide valuable insights into how different behavioral phenotypes are expressed in deferring brain activity response to drug challenge.

Quantitative pharmacologic MRI: mapping the cerebral blood volume response to cocaine in dopamine transporter knockout mice.

The use of pharmacologic MRI (phMRI) in mouse models of brain disorders allows noninvasive in vivo assessment of drug-modulated local cerebral blood volume changes (ΔCBV) as one correlate of neuronal and neurovascular activities. In this report, we employed CBV-weighted phMRI to compare cocaine-modulated neuronal activity in dopamine transporter (DAT) knockout (KO) and wild-type mice. Cocaine acts to block the dopamine, norepinephrine, and serotonin transporters (DAT, NET, and SERT) that clear their respective neurotransmitters from the synapses, helping to terminate cognate neurotransmission.

A uniplanar three-axis gradient set for in vivo magnetic resonance microscopy.

We present an optimized uniplanar magnetic resonance gradient design specifically tailored for MR imaging applications in developmental biology and histology. Uniplanar gradient designs sacrifice gradient uniformity for high gradient efficiency and slew rate, and are attractive for surface imaging applications where open access from one side of the sample is required. However, decreasing the size of the uniplanar gradient set presents several unique engineering challenges, particularly for heat dissipation and thermal insulation of the sample from gradient heating.

Competitive C-H and O-D bond fission channels in the UV photodissociation of the deuterated hydroxymethyl radical CH2OD.

Photodissociation studies of the CH2OD radical in the region 28,000-41,000 cm(-1) (357-244 nm), which includes excitation to the 3s, 3p(x), and 3p(z) states, are reported. H and D photofragments are monitored by using resonance-enhanced multiphoton ionization (REMPI) from the onset of H formation at approximately 30,500 cm(-1) to the origin band region of the 3pz(2A")<--1 2A" transition at 41,050 cm(-1). Kinetic energy distributions P(ET) and recoil anisotropy parameters as a function of kinetic energy, beta(eff)(ET), are determined by the core sampling technique for the channels producing H and D fragments.