Examining Schizophrenia Patient Postmortem Tissue
Andrea Lorincz, Mária M. Ashaber, and Zoltan Nusser
(see article e0645252025)
Genetic evidence suggests that atypical excitatory signaling in the human prefrontal cortex may contribute to schizophrenia. However, the proteins in excitatory synapses that are potentially involved in disease pathophysiology remain unknown. One way to identify schizophrenia-relevant protein changes at the level of individual synapses is to examine the postmortem tissue from patients, but technical limitations make this method difficult. Lorincz et al. overcame these technical limitations by using a new immunolocalization method. The authors found no differences at the majority of synapses, but excitatory synapses on inhibitory parvalbumin-expressing interneurons had lower NMDA receptor densities in the schizophrenia patient postmortem tissue. According to the authors, this study suggests that schizophrenia patients may have abnormal signaling at a subset of excitatory synapses and points to a receptor that may be involved. Furthermore, the approach used to assess the postmortem tissue may be informative for researchers studying other neurological conditions and diseases.
Immunofluorescent labeling in the dorsolateral prefrontal cortex of a schizophrenia subject. Expression of voltage-gated potassium channel 2.1 (Kv2.1, light blue), a marker for excitatory synapses (PSD-95, magenta) and a marker for inhibitory synapses (VGAT, green), is shown. See Lorincz et al. for more information.
Left Inferior Parietal Lobe Subregion Functions
Jiahong Zeng, Yuxin Liu, Chunyu Zhao, Zhenjiang Cui, Saiyi Jiao et al.
(see article e0307252025)
The left inferior parietal lobe (IPL) supports a wide range of cognitive functions. Herein, Zeng and colleagues shed light on how the left IPL's subregions contribute to cognitive processing. The authors used intracranial stereo-encephalography (SEEG) with representational similarity analysis (RSA) as 13 participants performed an oral reading task probing many dimensions of language processing such as visual recognition, lexicon retrieval, and pronunciation. Zeng et al. used this approach because SEEG captures neural activity dynamics with high resolution and RSA can directly link activity patterns to existing cognitive models. Thus, SEEG and RSA together allowed for a better understanding of language information processing and how it changes over time. Within the left IPL, roles of the supramarginal gyrus, the angular gyrus, and the lateral bank of the intraparietal sulcus were examined. Activity in the supramarginal gyrus represented early semantics of language processing followed by phonology, visual form, and later semantics. The angular gyrus was linked to early semantics and then visual form. The lateral bank of the intraparietal sulcus represented only the visual form. Notably, these IPL subregions dynamically coordinated their activity throughout the reading task. According to the authors, this work advances understanding of how information flows between IPL subregions to support language processing over time.
Footnotes
This Week in The Journal was written by Paige McKeon
