title: Follow-up of cortical activity and structure after lesion with laser speckle imaging and magnetic resonance imaging in nonhuman primates.
abstract: The nonhuman primate model is suitable to study mechanisms of functional recovery following lesion of the cerebral cortex (motor cortex), on which therapeutic strategies can be tested. To interpret behavioral data (time course and extent of functional recovery), it is crucial to monitor the properties of the experimental cortical lesion, induced by infusion of the excitotoxin ibotenic acid. In two adult macaque monkeys, ibotenic acid infusions produced a restricted, permanent lesion of the motor cortex. In one monkey, the lesion was monitored over 3.5 weeks, combining laser speckle imaging (LSI) as metabolic readout (cerebral blood flow) and anatomical assessment with magnetic resonance imaging (T2-weighted MRI). The cerebral blood flow, measured online during subsequent injections of the ibotenic acid in the motor cortex, exhibited a dramatic increase, still present after one week, in parallel to a MRI hypersignal. After 3.5 weeks, the cerebral blood flow was strongly reduced (below reference level) and the hypersignal disappeared from the MRI scan, although the lesion was permanent as histologically assessed post-mortem. The MRI data were similar in the second monkey. Our experiments suggest that LSI and MRI, although they reflect different features, vary in parallel during a few weeks following an excitotoxic cortical lesion.
authors.affiliation: University of Fribourg, Department of Physics, Ch. du Musée 3, CH-1700 Fribourg, Switzerland.
authors.forename: Jörn
authors.initials: J
authors.lastname: Peuser
authors.forename: Abderraouf
authors.initials: A
authors.lastname: Belhaj-Saif
authors.forename: Adjia
authors.initials: A
authors.lastname: Hamadjida
authors.forename: Eric
authors.initials: E
authors.lastname: Schmidlin
authors.forename: Anne-Dominique
authors.initials: AD
authors.lastname: Gindrat
authors.forename: Andreas Charles
authors.initials: AC
authors.lastname: Völker
authors.forename: Pavel
authors.initials: P
authors.lastname: Zakharov
authors.forename: Henri-Marcel
authors.initials: HM
authors.lastname: Hoogewoud
authors.forename: Eric M
authors.initials: EM
authors.lastname: Rouiller
authors.forename: Frank
authors.initials: F
authors.lastname: Scheffold
mesh_terms: D000818:Animals; D001927:Brain Diseases / Q000139:chemically induced / Q000473:pathology* / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003952:Diagnostic Imaging / Q000379:methods; D006651:Histocytochemistry; D007051:Ibotenic Acid / Q000009:adverse effects; D007091:Image Processing, Computer-Assisted; D007834:Lasers; D008252:Macaca fascicularis; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009044:Motor Cortex / Q000098:blood supply / Q000293:injuries / Q000473:pathology* / Q000503:physiopathology
chemical_list: D007051:Ibotenic Acid