(C) 2011 Elsevier Ltd. All rights reserved.”
“Histone acetylation plays a critical role during long-term memory formation. Several studies have demonstrated that the histone acetyltransferase (HAT) CBP is required A1331852 during long-term memory formation, but the involvement of other HAT proteins has not been extensively investigated. The HATs CBP and p300 have at least
400 described interacting proteins including transcription factors known to play a role in long-term memory formation. Thus, CBP and p300 constitute likely candidates for transcriptional coactivators in memory formation. In this study, we took a loss-of-function approach to evaluate the role of p300 in long-term memory formation. We used conditional knock-out mice in which the deletion of p300 is restricted to the postnatal Selleck CA3 phase and to subregions of the forebrain. We found that p300 is required for the formation of long-term recognition memory and long-term contextual fear memory in the CA1 area of the hippocampus and cortical areas.”
“The vestibular system contributes to a wide range of functions, from postural and oculomotor reflexes to spatial representation and cognition. Vestibular
signals are important to maintain an internal, updated representation of the body position and movement in space. However, it is not clear to what extent they are also necessary to mentally simulate movement in situations that do not involve displacements of the body, as in mental imagery. The present study assessed how vestibular loss can affect object-based mental transformations (OMTs), i.e., imagined rotations or translations of objects relative to the environment. Participants performed one task of mental rotation of 3D-objects and two mental scanning tasks dealing with the ability to build and manipulate mental images that have metric
properties. Meniere’s disease patients were tested before unilateral vestibular neurotomy and during the recovery period (1 week and 1 month). CB-5083 nmr They were compared to healthy participants tested at similar time intervals and to bilateral vestibular-defective patients tested after the recovery period. Vestibular loss impaired all mental imagery tasks. Performance varied according to the extent of vestibular loss (bilateral patients were frequently the most impaired) and according to the time elapsed after unilateral vestibular neurotomy (deficits were stronger at the early stage after neurotomy and then gradually compensated). These findings indicate that vestibular signals are necessary to perform OMTs and provide the first demonstration of the critical role of vestibular signals in processing metric properties of mental representations. They suggest that vestibular loss disorganizes brain structures commonly involved in mental imagery, and more generally in mental representation. (C) 2011 Elsevier Ltd. All rights reserved.