Abnormalities in dendritic spines have long been associated with cognitive dysfunction and neurodevelopmental delay, whereas rapid changes in spine shape underlie synaptic plasticity. The key regulators of cytoskeletal reorganization in dendrites and spines are the Rho GTPases, which modify actin polymerization in response to synaptic signaling. Rho GTPase activity is modulated by multiple regu...

Cofilin and other Actin-regulating proteins are essential in regulating the shape of dendritic spines, which are sites of neuronal communications in the brain, and their malfunctions are implicated in neurodegeneration related to aging. The analysis of cofilin motility in dendritic spines using fluorescence video-microscopy may allow for the discovery of its effects on synaptic functions. To da...

The modulation of synaptic strength associated with learning is post-synaptically regulated by changes in density and shape of dendritic spines. The transcription factor CREB (cAMP response element binding protein) is required for memory formation and in vitro dendritic spine rearrangements, but its role in learning-induced remodeling of neurons remains elusive. Using transgenic mice conditiona...

Not only from our daily experience but from learning experiments in animals, we know that the establishment of long-lasting memory requires repeated practice. However, cellular backgrounds underlying this repetition-dependent consolidation of memory remain largely unclear. We reported previously using organotypic slice cultures of rodent hippocampus that the repeated inductions of LTP (long-ter...

Objective: Motor neurons (MNs) die in amyotrophic lateral sclerosis (ALS), a clinically heterogeneous neurodegenerative disease of unknown etiology. In human or rodent studies, MN loss is preceded by increased excitability. As increased neuronal excitability correlates with structural changes in dendritic arbors and spines, we have examined longitudinal changes in dendritic structure in vulnera...

Pozzo-Miller, Lucas D., Takafumi Inoue, and Diane Dieuliis Murphy. Estradiol increases spine density and NMDA-dependent Ca transients in spines of CA1 pyramidal neurons from hippocampal slices. J. Neurophysiol. 81: 1404–1411, 1999. To investigate the physiological consequences of the increase in spine density induced by estradiol in pyramidal neurons of the hippocampus, we performed simultaneou...

Changes in dendritic spine turnover are a major mechanism of experience-dependent plasticity in the adult neocortex. Dendritic spine plasticity may also contribute to functional recovery after stroke, but in that setting its expression may be complicated by alterations in local tissue perfusion, especially around the infarct. Using adult Thy-1 GFP-M mice, we simultaneously recorded long-term sp...

Dendrites and dendritic spine density regress extensively during aging in rats housed under standard conditions (SC), which can be ameliorated by housing in the enriched environment (EE). This event is particularly pronounced on neurons where high rates of plasticity are conceivable, such as on projection neurons of archicortical regions of dentate gyrus'. However, effects of EE on neocortical ...

The central circadian pacemaker, the suprachiasmatic nucleus (SCN), encodes day length information by mechanisms that are not well understood. Here, we report that genetic ablation of miR-132/212 alters entrainment to different day lengths and non-24 hr day-night cycles, as well as photoperiodic regulation of Period2 expression in the SCN. SCN neurons from miR-132/212-deficient mice have signif...

We recently reported that prolonged exposure to the glucocorticoid receptor (GR) ligand corticosterone impairs decision-making that is dependent on the predictive relationship between an action and its outcome (Gourley et al.; Proceedings of the National Academy of Sciences, 2012). Additionally, acute GR blockade, when paired with action-outcome conditioning, also blocks new learning. We then s...