Pitt-Hopkins Syndrome: intellectual disability due to loss of TCF4-regulated gene transcription

TCF4 (transcription factor 4; E2-2, ITF2) is a transcription factor that when haplo-insufficient causes Pitt-Hopkins Syndrome (PTHS), an autism-spectrum disorder that is associated with pervasive developmental delay and severe intellectual disability. The TCF4 gene is also a risk factor with highly significant linkage to schizophrenia, presumably via overexpression of the TCF4 gene product in the central nervous system. This review will present an overview of the clinical manifestations of PTHS and relate those clinical attributes to the underlying molecular genetics of TCF4. In order to provide a molecular biological context for the loss of function of TCF4 in PTHS, the review will also present a brief overview of the basic biochemistry of TCF4-mediated regulation of cellular and neuronal gene expression. In the final section of this review, I will discuss and speculate upon possible roles for the TCF4 transcription factor in neuronal function and comment upon how understanding these roles may give new insights into the molecular neurobiology of human cognition.

The variation of N400 event-related potentials during language cognition of different paradigms in stroke patients / 中华物理医学与康复杂志

Objective To explore the cognition processes of language in stroke patients by characterizing the differences between the event-related potentials (ERPs) N400 evoked bypicture-word andsentence-wordparadigms.Methods Twenty patients with a single brain lesion resulting from a first episode of stroke were tested along with 20 normal controls.Their N400 ERPs were tested using pictures and sentences as activating stimuli and phrases composed of nouns and verbs as the target stimuli.The N400 potentials were recorded from electrodes located at Fz,Pz,T3 and T4 positions of the International 10-20 system.The N400 latencies and amplitudes and the behavioral responses of the experimental and control groups were compared.Results The latencies were longer and the amplitudes were lower in response to sentence activation than to picture activation.The differences in terms of amplitude were the greatest with N400 recorded from Pz.The responses to the target stimuli were not significantly different with regard to the types of stimuli and recording location.The average response time was longer and the error rate was higher in response to sentence activation than to picture activation.Conclusion Multiple accesses,activating stimuli and integrating processes are involved in language cognition.The brain is more sensitive and accurate in response to picture stimuli in language cognition.The response to sentence stimuli is slower,and the error rate is higher.This suggests that it is better to usc varied prime stimuli in teaching children languages.