Examination of Glutamate and mGluR5 in Psychiatric Disorders

Verbal assessments as well as computer testing.

Anatomical MRIs will be performed on a Siemens 3T Trio at Yale. MR acquisition will be a Sag 3D magnetization-prepared rapid gradient-echo (MPRAGE) sequence with 3.34 ms echo time, 2,500 ms repetition time, 1,000 ms inversion time, 7 degree flip angle, and 180 Hz/pixel bandwidth. The image dimensions will be 256 x 256 x 176 and pixel size 0.98 x 0.98 x 1.0 mm. Resting state MRIs will also be obtained as follows: We will be doing 2 six minute scans with subjects in the scanner, eyes open, fixating a cross. TR = 3 secs 45 slices x 3 mm slice thickness = 13.5 cm. In plane resolution = 3 x 3 mm, slice acquisition order = ascending.

High Resolution Research Tomograph (HRRT), the highest resolution human brain scanner available, or HR+ will be used to image subjects. Vital signs (blood pressure, pulse, respiration) will be obtained before and after radiotracer administration. An antecubital venous catheter will be used for IV administration of the radiotracer and for venous blood sampling. A radial artery catheter will be inserted by an experienced physician before the PET scan. At the beginning of each scan, the subject's head will be immobilized and a 6 minute transmission scan using an orbiting 137Cs (HRRT) or 68GE (HR+) point-source is obtained and used for attenuation correction. PET scans will be acquired using bolus or bolus plus constant infusion administration of FPEB or ABP688.