Overexpression of Calretinin Enhances Short-Term Synaptic Depression.

Analysis of the effects of various proteins on short-term synaptic plasticity is a difficult task, which may require the use of knockout animals. Here, we propose an alternative experimental approach for studying the roles of desired proteins in synaptic plasticity. We packed the Ca-binding protein calretinin and the fluorescent protein Venus into AAV and injected the concentrated viral suspension into the neocortex of newborn rats.

Hippocampal GluA1 expression in Gria1 mice only partially restores spatial memory performance deficits.

Spatial working memory (SWM) is an essential cognitive function important for survival in a competitive environment. In rodents SWM requires an intact hippocampus and SWM expression is impaired in mice lacking the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunit GluA1 (Gria1 mice). Here we used viral gene transfer to show that re-expression of GluA1 in the hippocampus can affect the behavioral performance of GluA1 deficient mice.

Hypertrophy and altered activity of the adrenal cortex in Homer 1 knockout mice.

Homer 1 gene products are involved in synaptic transmission and plasticity, and hence, distinct behavioral abnormalities, including anxiety- and depression-like behaviors, have been observed in Homer 1 knockout (KO) mice. Here we report that Homer 1 KO mice additionally exhibit a pronounced endocrine phenotype, displaying a profoundly increased adrenal gland weight and increased adrenal/body weight ratio. Histological examinations of Homer 1 deficient adrenal glands revealed an increased size of the adrenal cortex, especially the sizes of the zona fasciculata and zona glomerulosa.

p45NF-E2 represses Gcm1 in trophoblast cells to regulate syncytium formation, placental vascularization and embryonic growth.

Absence of the leucine zipper transcription factor p45NF-E2 results in thrombocytopenia, impaired placental vascularization and intrauterine growth restriction (IUGR) in mice. The mechanism underlying the p45NF-E2-dependent placental defect and IUGR remains unknown. Here, we show that the placental defect and IUGR of p45NF-E2 (Nfe2) null mouse embryos is unrelated to thrombocytopenia, establishing that embryonic platelets and platelet-released mediators are dispensable for placentation.

AMPA receptor signaling through BRAG2 and Arf6 critical for long-term synaptic depression.

Central nervous system synapses undergo activity-dependent alterations to support learning and memory. Long-term depression (LTD) reflects a sustained reduction of the synaptic AMPA receptor content based on targeted clathrin-mediated endocytosis. Here we report a current-independent form of AMPA receptor signaling, fundamental for LTD.