PIXSIC: A Wireless Intracerebral Radiosensitive Probe in Freely Moving Rats.

The aim of this study was to demonstrate the potential of a wireless pixelated β+-sensitive intracerebral probe (PIXSIC) for in vivo positron emission tomographic (PET) radiopharmacology in awake and freely moving rodents. The binding of [(11)C]raclopride to D2 dopamine receptors was measured in anesthetized and awake rats following injection of the radiotracer. Competitive binding was assessed with a cold raclopride injection 20 minutes later.

The potential of a radiosensitive intracerebral probe to monitor 18F-MPPF binding in mouse hippocampus in vivo.

Unlabelled: As mouse imaging has become more challenging in preclinical research, efforts have been made to develop dedicated PET systems. Although these systems are currently used for the study of physiopathologic murine models, they present some drawbacks for brain studies, including a low temporal resolution that limits the pharmacokinetic study of radiotracers. The aim of this study was to demonstrate the ability of a radiosensitive intracerebral probe to measure the binding of a radiotracer in the mouse brain in vivo.

Combining the radiosensitive Beta MicroProbe to nuclear magnetic resonance: theoretical approach for in vivo studies in small animals.

In vivo small animal imaging with multiple modalities has become an important tool in modern biomedical research. Indeed, combining exploratory techniques allows simultaneous recording of complementary data, which is required to elucidate complex physiopathological mechanisms. In this field, because of strict technical constraints in vivo, an exciting challenge remains in the combination of Nuclear Magnetic Resonance (NMR) and Positron Emission Tomography (PET).

Arterial input function measurement without blood sampling using a beta-microprobe in rats.

Unlabelled: The evaluation of every new radiotracer involves pharmacokinetic studies on small animals to determine its biodistribution and local kinetics. To extract relevant biochemical information, time-activity curves for the regions of interest are mathematically modeled on the basis of compartmental models that require knowledge of the time course of the tracer concentration in plasma. Such a time-activity curve, usually termed input function, is determined in small animals by repeated blood sampling and subsequent counting in a well counter.

In vivo quantification of localized neuronal activation and inhibition in the rat brain using a dedicated high temporal-resolution beta +-sensitive microprobe.

Understanding brain disorders, the neural processes implicated in cognitive functions and their alterations in neurodegenerative pathologies, or testing new therapies for these diseases would benefit greatly from combined use of an increasing number of rodent models and neuroimaging methods specifically adapted to the rodent brain. Besides magnetic resonance (MR) imaging and functional MR, positron-emission tomography (PET) remains a unique methodology to study in vivo brain processes. However, current high spatial-resolution tomographs suffer from several technical limitations such as high cost, low sensitivity, and the need of restraining the animal during image acquisition.

SIC, an intracerebral beta(+)-range-sensitive probe for radiopharmacology investigations in small laboratory animals: binding studies with (11)C-raclopride.

Unlabelled: Our aim was to show the ability of a recently developed beta(+)-range-sensitive intracerebral probe (SIC) to measure, in vivo, the binding of radioligands in small animals.

Methods: The potential of the device for pharmacokinetic studies was evaluated by measurement of the dynamic striatal binding of (11)C-raclopride, a well-documented D(2) dopaminergic receptor ligand, in rat brain after intravenous injection of the labeled compound. The effects of preinjection of the unlabeled ligand (raclopride, 2 mg/kg intravenously) and of increasing the synaptic dopamine level (amphetamine treatment, 1 mg/kg intravenously) or of depleting synaptic dopamine (reserpine pretreatment, 5 mg/kg intraperitoneally) on in vivo (11)C-raclopride binding were monitored by SIC.