![]() ![]() The EEG phenotypes of Grin2a and Akap11 mutant mice show a variety of abnormal features that overlap considerably with human schizophrenia patients, reflecting systems-level changes caused by Grin2a and Akap11 deficiency. Sleep spindle density was reduced in a gene dose-dependent manner in Akap11 mutants, whereas Grin2a mutants showed increased sleep spindle density. Grin2a and Akap11 mutants exhibited increased resting gamma power, attenuated auditory steady-state responses (ASSR) at gamma frequencies, and reduced responses to unexpected auditory stimuli during mismatch negativity (MMN) tests. Does loss of Grin2a or Akap11 in mice also result in EEG abnormalities? We monitored EEG in heterozygous and homozygous knockout Grin2a and Akap11 mutant mice compared with their wild-type littermates, at 3- and 6-months of age, across the sleep/wake cycle and during auditory stimulation protocols. Accessible in both humans and rodents, electroencephalogram (EEG) recordings offer a window into brain activity and display abnormal features in schizophrenia patients. AKAP11 and GRIN2A mutations are also associated with bipolar disorder, and epilepsy and developmental delay/intellectual disability, respectively. Exome sequencing studies have uncovered rare, loss-of-function variants that greatly increase risk of schizophrenia, including loss-of-function mutations in GRIN2A (aka GluN2A or NR2A, encoding the NMDA receptor subunit 2A) and AKAP11 (A-Kinase Anchoring Protein 11). All rights reserved.Schizophrenia is a heterogeneous psychiatric disorder with a strong genetic basis, whose etiology and pathophysiology remain poorly understood. These results have significant methodological implications for future FPVS studies (of both facial emotion and identity), suggesting that it is crucial to vary base stimuli sufficiently, such that simple physical differences between base and oddball stimuli cannot give rise to neural oddball responses.Īlexithymia Facial expressions Fast periodic visual stimulation Implicit.Ĭopyright © 2019 Elsevier Ltd. In the mixed-emotions paradigm, however, inversion effects in a central cluster (indicative of higher level emotion processing) were present in typical participants, but not those with alexithymia (who are impaired at emotion recognition), suggesting that only the mixed-emotions paradigm reflects emotion recognition rather than detection of a lower-level visual change from baseline. In the fixed-emotion paradigm, typical inversion effects were observed at occipital sites. However, in the 'fixed-emotion' paradigm, stimulus image varied at every presentation but the emotion in the base stream remained constant, and in the 'mixed-emotions' paradigm, both stimulus image and emotion varied at every presentation, with only the oddball emotion (disgust) remaining constant. In both paradigms, the oddball emotional expression was different from that of the base stream images. This study tested two new FPVS paradigms designed to distinguish recognition of expressions of emotion from detection of visual change from the base stream. However, because previous studies have utilised identical images as base stimuli, physical differences between base and oddball stimuli, rather than recognition of identity or emotion, may have been responsible for oddball responses. Fast Periodic Visual Stimulation (FPVS) with oddball stimuli has been used to investigate discrimination of facial identity and emotion, with studies concluding that oddball responses indicate discrimination of faces at the conceptual level (i.e., discrimination of identity and emotion), rather than low-level perceptual (visual, image-based) discrimination. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |