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In vivo research studies requiring repeated blood sampling ideally involve a simple collection technique while also minimizing stress and discomfort to the animal. Implantation of an indwelling vascular catheter provides a simple, pain-free route for repeated blood collection over an extended period of time. Ferrets were implanted with indwelling jugular vein catheters (JVCs) for daily collection of blood samples over the course of a three week study period. To prevent damage to the catheters by other ferrets, JVCs were attached to Vascular Access Buttons™ (VABs) due to their secure and self-contained design. Following surgery, no animals exhibited signs of disruption to their catheter as a result of group housing conditions. In combination with an indwelling catheter, the JVC/VAB system improved the ease of blood collection, requiring only a PinPort™ injector attached to a syringe. The VAB allowed blood collection from group-housed ferrets to be performed by a single technician, without the use of anesthesia, for up to 21 consecutive days.

In vivo research studies requiring repeated blood sampling ideally involve a simple collection technique while also minimizing stress and discomfort to the animal. Implantation of an indwelling vascular catheter provides a simple, pain-free route for repeated blood collection over an extended period of time. Ferrets were implanted with indwelling jugular vein catheters (JVCs) for daily collection of blood samples over the course of a three week study period. To prevent damage to the catheters by other ferrets, JVCs were attached to Vascular Access Buttons™ (VABs) due to their secure and self-contained design. Following surgery, no animals exhibited signs of disruption to their catheter as a result of group housing conditions. In combination with an indwelling catheter, the JVC/VAB system improved the ease of blood collection, requiring only a PinPort™ injector attached to a syringe. The VAB allowed blood collection from group-housed ferrets to be performed by a single technician, without the use of anesthesia, for up to 21 consecutive days. [ABSTRACT FROM AUTHOR]

The Group I metabotropic glutamate receptor subtype 5 (mGluR5) is widely distributed in the brain with dense expression in the cerebral cortex, hippocampus, and basal ganglia. These receptors have been implicated in psychiatric and neurological disorders such as schizophrenia, Fragile X syndrome, addiction, anxiety/depression, Parkinson's disease and neuropathic pain. The present study evaluated the effects of the mGluR5 negative allosteric modulators (NAMs) 4-difluoromethoxy-3-(pyridine-2-ylethynyl)phenyl)5H-pyrrolo[3,4-b]pyridine-6(7H)-yl methanone (GRN-529) and methyl (3aR,4S,7aR)-4-hydroxy-4-[(3-methylphenyl)ethynyl]octahydro-1H-indole-1-carboxylate (AFQ056) on polysomnographic (PSG) and quantitative electroencephalographic (qEEG) measures in freely moving rats. Furthermore, the anxiolytic profile of GRN-529 was characterized in anesthetized rats by measuring stimulation-induced hippocampal theta oscillation. The present findings demonstrate that inhibition of mGluR5 via its allosteric site profoundly modulates high-level neuronal network activities as indicated by changes in sleep-wake activity and power distribution of qEEG. Both GRN-529 and AFQ056 reduced the total time spent in rapid-eye movement with AFQ056 producing a significant increase in wakefulness at the highest dose tested. Additionally, qEEG revealed significant compound-induced increases in delta power concomitant with more subtle decreases in theta and alpha band power. Receptor occupancy (RO) studies revealed that GRN-529 and AFQ056 at all doses resulted in over 45% mGluR5 occupancy. Furthermore, GRN-529 dose-dependently decreased elicited hippocampal theta frequency, consistent with previous findings using clinically active anxiolytic compounds. The described changes in neurophysiological signals identified in freely moving rats may be considered suitable translational biomarkers for the clinical evaluation of mGluR5 NAMs., (Copyright © 2013 Elsevier Ltd. All rights reserved.)