Assessment of locus and extent of neurotoxic lesions in monkeys using neuroimaging techniques: a replication.
In a recent study, [Hippocampus 11 (2001) 361] demonstrated that in vivo neuroimaging techniques could be used to accurately quantify the extent of neuronal damage after ibotenic acid injections in non-human primates. The present study was undertaken to replicate these findings and to further estimate whether the concentration of ibotenic acid used (10-15 mg/ml) to produce the neuronal loss did not affect the fibers coursing within or around the targeted brain area. Magnetic resonance (MR) images (T1-weighted and FLAIR) were acquired in three monkeys before and after they received neurotoxic lesions of the hippocampal formation. The postsurgical FLAIR images were taken 7-10 days after surgery to visualize the hyperintense signals produced by increased edema at the injection sites. One year post-surgically, T1-weighted images were acquired and compared with T1-weighted images obtained pre-surgery to estimate reduction in hippocampal volume resulting from neuronal loss. Estimated neuronal loss was then compared with actual cell loss found during histological evaluation of brain tissue. Both neuroimaging techniques accurately estimated the extent of hippocampal damage and damage to surrounding structures. In addition, the concentration of ibotenic acid (10 mg/ml) used in the present study did not appear to have significantly damaged or de-myelinated fibers coursing through or around the hippocampal formation. Together with the previous results of [Hippocampus 11 (2001) 361], the present data strongly demonstrate that in vivo neuroimaging techniques provide powerful tools to estimate reliably and rapidly the extent and localization of brain lesions in non-human primates.
Nemanic
Sarah
S
Department of Neurobiology and Anatomy, University of Texas Health Science Center, 6431 Fannin Street, Houston, TX 77030, USA.
Alvarado
Maria C
MC
Price
Roger E
RE
Jackson
Edward F
EF
Bachevalier
Jocelyne
J
D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000473:pathology; D016923:Cell Death / Q000187:drug effects; D005260:Female; D006624:Hippocampus / Q000187:drug effects / Q000473:pathology; D007051:Ibotenic Acid / Q000494:pharmacology*; D008253:Macaca mulatta; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009412:Nerve Fibers / Q000187:drug effects / Q000502:physiology; D009498:Neurotoxins / Q000494:pharmacology*; D015203:Reproducibility of Results; D016622:Silver Staining / Q000379:methods
D009498:Neurotoxins; D007051:Ibotenic Acid