News | January 13, 2015

PET Shows Benefits of Rehabilitative Training After Brain Injury

Brain imaging captures remapping of motor functions in monkeys

PET, damaged brain, remapping, Riken, AIST, motor function

January 13, 2015 — Scientists at the Riken Center for Life Science Technologies, along with researchers from the AIST Human Technology Research Institute in Japan, have identified a time-dependent interplay between two brain regions that contributes to the recovery of motor function after focal brain damage, such as a stroke. Published in the Journal of Neuroscience, the research shows that when motor functions are remapped through rehabilitative training, brain regions relatively distant from a lesion are recruited during the initial stages and functional connections with regions near the lesion are strengthened during the latter stages.

The research team investigated the special kind of neural plasticity that allows the recovery of motor function after brain damage, focusing on changes that occur during the course of rehabilitative training. This kind of training is known to promote structural and functional alterations in the brain that improve impaired motor ability, but how it does so is a question that neuroscientists are still trying to answer.

The team studied the rehabilitation process in monkeys that had suffered injury to the region of the cerebral cortex that controls hand movements. This region of the primary motor cortex is especially needed for fine movements, such as those required to grip and manipulate small objects using fingers. To facilitate recovery of motor function, the researchers taught monkeys to quickly and repeatedly grab a piece of potato through a small opening using their thumbs and index fingers — a task that requires a high degree of manual dexterity.

As expected, the team found that performing this task 30 minutes a day for several weeks after injury resulted in greatly improved motor function. To estimate changes in brain activity associated with the recovery, they imaged the regional brain activity using H215O-positron emission tomography (PET) before injury and at the early and late stages of recovery while monkeys performed the task. They found that activity in the ventral premotor cortex — a brain region somewhat distant from the injury — was higher during the early stage of recovery than before the injury. They also conducted what is known as a psychophysiological interactions (PPI) analysis and found that when monkeys performed the task in the later stages of recovery, connections between the lesion site and regions of primary motor cortex immediately surrounding it became stronger.

To verify whether the changes in these regions were in fact necessary for the recovery, they temporarily inactivated them before injury and at the recovery stages. They found that inactivation of the ventral premotor region on the same side of the brain as the lesion impaired precision grip during the early stages of recovery — even when it was limited to regions that had not been essential to hand movements before the injury. They also found that the area surrounding the injury became devoted to movements related to precision grip. During the later stage of recovery, inactivating this area only affected precision grips, but not other types of grips that had been impaired by inactivation before the lesion.

When explaining their new findings, Yumi Murata from AIST noted, "They will likely contribute to the development of new rehabilitation techniques and drugs, as well as new ways to evaluate rehabilitative training."

Hirotaka Onoe from Riken added, "New rehabilitation techniques will help reduce the burden that these types of strokes have on the patients and their families."

For more information: www.clst.riken.jp/en/

Related Content

Study Demonstrates First Human Application of Novel PET Tracer for Prostate Cancer

Transaxial 11Csarcosine hybrid PET/CT showed a (triangulated) adenocarcinoma in the transition zone of the anterior right prostate gland on PET (A), CT (B), and a separately obtained T2?weighted MR sequence (C) with resulting PET/MRI registration (D). Image courtesy of M. Piert et al., University of Michigan, Ann Arbor, Mich.

News | Radiopharmaceuticals and Tracers | August 16, 2017
In the featured translational article in the August issue of The Journal of Nuclear Medicine, researchers at the...
PET/CT Tracer Identifies Vulnerable Lesions in Non-Small Cell Lung Cancer Patients

Example of a patient with an upper left lung NSCLC: A: FDG; B: FDG PET/CT; C: Planning radiotherapy based on FDG (66Gy) with BTVm (GTV), CTV and PTV; D: PET FMISO E: FMISO PET/CT; F: boost based on the FMISO PET (76Gy) with BTVh (biological hypoxic target volume) and PTV boost. Credit: QuantIF – LITIS EA 4108 – FR CNRS 3638, Henri Becquerel Cancer Center, Rouen, France

News | PET-CT | July 14, 2017
July 14, 2017 — Fluorine-18 (18F)-fluoromisonidazole (FMISO) is a positron emission tomography (PET)...
Novel PET Tracer Detects Small Blood Clots

PET images (MIP 0-60 min) of three Cynomolgus monkeys. Strong signals are detected at the sites where inserted catheters had roughened surfaces. Almost no other background signal is visible. Only accumulation in the gallbladder becomes visible at the bottom of the image. Credit: Piramal Imaging GmbH, Berlin Germany.

News | PET Imaging | July 07, 2017
July 7, 2017 — Blood clots in veins a
Sponsored Content | Videos | Clinical Decision Support | June 29, 2017
Rami Doukky, M.D., system chair, Division of Cardiology, professor of medicine, Cook County Health and Hospitals Syst
Dual-Agent PET/MR With Time of Flight Detects More Cancer

Tc-99m MDP bone scan (left) is negative for osseous lesions. NaF/FDG PET/MRI (right and second slide) confirms absence of bone metastases, but shows liver metastases. Image courtesy of Stanford University.

News | PET-MRI | June 20, 2017
Simultaneous injections of the radiopharmaceuticals fluorine-18 fluorodeoxyglucose (18F-FDG) and 18F-sodium fluoride (...
Combined Optical and Molecular Imaging Could Guide Breast-Conserving Surgery

WLE specimen from a patient with a grade 3, ER-/HER2-, no special type (NST) carcinoma. (A) Cerenkov image; (B) Grey-scale photographic image overlaid with Cerenkov signal. An increased signal from the tumor is visible (white arrows); mean radiance is 871 ± 131 photons/s/cm2/sr, mean TBR is 3.22. Both surgeons measured the posterior margin (outlined in blue) as 2 mm (small arrow); a cavity shaving would have been performed if the image had been available intraoperatively. The medial margin (outlined in green) measured >5 mm by both surgeons. Pathology ink prevented assessing the lateral margin; a phosphorescent signal is visible (open arrows). (C) Specimen radiography image. The absence of one surgical clip to mark the anterior margin, and the odd position of the superior margin clip (white arrow) prevented reliable margin assessment. (D) Combined histopathology image from two adjacent pathology slides on which the posterior margin (bottom of image) and part of the primary tumor are visible (open arrows). The distance from the posterior margin measured 3 mm microscopically (double arrow). The medial margin is > 5 mm (not present in image). Credit: A. D. Purushotham, M.D., King’s College London, UK

News | Nuclear Imaging | June 20, 2017
June 20, 2017 — Breast-conserving surgery (BCS) is the primary treatment for early-stage...
A 77-year-old male with recurrent lymph node and pulmonary metastases detected by Ga-68 PSMA PET/CT but not by conventional imaging

A 77-year-old male with recurrent lymph node and pulmonary metastases detected by Ga-68 PSMA PET/CT but not by conventional imaging. Graphic courtesy of the Department of Nuclear Medicine, Royal North Shore Hospital, Sydney

News | Prostate Cancer | June 15, 2017
An estimated one in seven American men will be affected by prostate cancer in their lifetime. Prostate-specific...
Dual-labeled PSMA-inhibitors for the diagnosis and therapy of prostate cancer

IMAGE OF THE YEAR: Dual-labeled PSMA-inhibitors for the diagnosis and therapy of prostate cancer. Technology of dual-labeled PSMA-inhibitors for PET/CT imaging and fluorescence-guided intraoperative identification of metastases. This work might help to establish a new treatment regimen for more precise and sensitive pre-, intra- and post-therapeutic detection of prostate cancer.

Credit: Courtesy of A. Baranski, M. Schäfer, U. Bauder-Wüst, M. Roscher, J. Schmidt, E. Stenau, L. Maier-Hein, M. Eder, K. Kopka, German Cancer Research Center, Heidelberg, Germany; T. Simpfendörfer, B. Hadaschik, U. Haberkorn, Heidelberg University Hospital, Heidelberg, Germany; PET-image: Afshar-Oromieh et al., EJNMMI 2013; 40(4); STED-image: J. Matthias, German Cancer Research Center.

This study was supported by the VIP+ fund, Federal Ministry of Education & Research (BMBF), Germany.

Scientific Paper 531: “Preclinical evaluation of dual-labeled PSMA-inhibitors for the diagnosis and therapy of prostate cancer.” A. Baranski, M. Schäfer, U. Bauder-Wüst, M. Roscher, J. Schmidt, E. Stenau, L. Maier-Hein, M. Eder, K. Kopka, German Cancer Research Center (DKFZ), Heidelberg, Germany; T. Simpfendörfer, B.  Hadaschik, U. Haberkorn, University Hospital, Heidelberg, Germany. Presented at SNMMI’s 64th Annual Meeting, June 10-14, 2017, Denver, Colo.

News | Prostate Cancer | June 15, 2017
In the battle against metastatic prostate cancer, the removal of lymph node metastases using image-guided surgery may...
Overlay Init