RESUMO
Morphemes are the smallest meaning-carrying units in human language, and are among the most basic building blocks through which humans express specific ideas and concepts. By using time-resolved cortical stimulations, neural recordings, and focal lesion evaluations, we show that inhibition of a small cortical area within the left dominant posterior-superior temporal lobe selectively impairs the ability to produce appropriate functional morphemes but does not distinctly affect semantic and lexical retrieval, comprehension, or articulation. Additionally, neural recordings within this area reveal the localized encoding of morphological properties and their planned production prior to speech onset. Finally, small lesions localized to the gray matter in this area result in a selective functional morpheme-production deficit. Collectively, these findings reveal a detailed division of linguistic labor within the posterior-superior temporal lobe and suggest that functional morpheme processing constitutes an operationally discrete step in the series of computations essential to language production.
Assuntos
Astrocitoma/diagnóstico por imagem , Neoplasias Encefálicas/diagnóstico por imagem , Glioblastoma/diagnóstico por imagem , Substância Cinzenta/fisiologia , Idioma , Fala/fisiologia , Lobo Temporal/fisiologia , Adulto , Astrocitoma/patologia , Astrocitoma/fisiopatologia , Astrocitoma/cirurgia , Mapeamento Encefálico , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/fisiopatologia , Neoplasias Encefálicas/cirurgia , Compreensão , Craniotomia , Estimulação Elétrica , Feminino , Glioblastoma/patologia , Glioblastoma/fisiopatologia , Glioblastoma/cirurgia , Substância Cinzenta/anatomia & histologia , Substância Cinzenta/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Masculino , Fonética , Semântica , Lobo Temporal/anatomia & histologia , Lobo Temporal/diagnóstico por imagemAssuntos
Antineoplásicos/uso terapêutico , Vacinas Anticâncer/uso terapêutico , Drogas em Investigação/uso terapêutico , Glioblastoma/tratamento farmacológico , Imunoterapia/métodos , Antineoplásicos/administração & dosagem , Vacinas Anticâncer/administração & dosagem , Vacinas Anticâncer/imunologia , Ensaios Clínicos como Assunto , Drogas em Investigação/administração & dosagem , Glioblastoma/genética , Glioblastoma/imunologia , Humanos , Isocitrato Desidrogenase/antagonistas & inibidores , Isocitrato Desidrogenase/genética , MutaçãoRESUMO
The investigation of metabolic pathways disturbed in isocitrate dehydrogenase (IDH) mutant tumors revealed that the hallmark metabolic alteration is the production of D-2-hydroxyglutarate (D-2HG). The biological impact of D-2HG strongly suggests that high levels of this metabolite may play a central role in propagating downstream the effects of mutant IDH, leading to malignant transformation of cells. Hence, D-2HG may be an ideal biomarker for both diagnosing and monitoring treatment response targeting IDH mutations. Magnetic resonance spectroscopy (MRS) is well suited to the task of noninvasive D-2HG detection, and there has been much interest in developing such methods. Here, we review recent efforts to translate methodology using MRS to reliably measure in vivo D-2HG into clinical research.