Actin filaments and microtubules in dendritic spines

Abstract

Dendritic spines are small protrusions emerging from their parent dendrites, and their morphological changes are involved in synaptic plasticity. These tiny structures are composed of thousands of different proteins belonging to several subfamilies such as membrane receptors, scaffold proteins, signal transduction proteins, and cytoskeletal proteins. Actin filaments in dendritic spines consist of double helix of actin protomers decorated with drebrin and ADF/cofilin, and the balance of the two is closely related to the actin dynamics, which may govern morphological and functional synaptic plasticity. During development, the accumulation of drebrinbinding type actin filaments is one of the initial events occurring at the nascent excitatory postsynaptic site, and plays a pivotal role in spine formation as well as small GTPases. It has been recently reported that microtubules transiently appear in dendritic spines in correlation with synaptic activity. Interestingly, it is suggested that microtubule dynamics might couple with actin dynamics. In this review, we will summarize the contribution of both actin filaments and microtubules to the formation and regulation of dendritic spines, and further discuss the role of cytoskeletal deregulation in neurological disorders.

Prosapip1-Dependent Synaptic Adaptations in the Nucleus Accumbens Drive Alcohol Intake, Seeking, and Reward

“…The consequence of mTORC1-dependent translation of CRMP-2 by alcohol is the induction of microtubules assembly (Liu et al, 2017). Microtubules are present in dendritic shafts and the infiltration of micro-tubules into dendritic spines is correlated with increased F-actin and spine enlargement (Shirao and González-Billault, 2013). Thus, we postulate that alcohol via the activation of mTORC1 in the NAc produces orchestrated alterations of both microtu-bules and actin dynamics at the spines that lead to changes in synaptic strength that alter the landscape of the neuronal structure in response to excessive alcohol use.…”

N‐methyl‐d‐aspartate receptor mediated calcium influx supports in vitro differentiation of normal mouse megakaryocytes but proliferation of leukemic cell lines

“…Our results suggest a link between NMDAR function and the cell cytoskeleton in megakaryocytes, as it is also known to occur in neurons. NMDARs interact with actin and microtubules to physically re‐shape neurons in response to neuronal firing,45, 46 including formation of cytoplasmic filopodia and dendritic spines 47, 48. There are also other examples of a similar link in non‐neuronal cells.…”

Plasticity-related Gene 5 Promotes Spine Formation in Murine Hippocampal Neurons

“…So far, PRG5 was related to induction of filopodia in different cell lines and to formation of neurites and branches in cortical immature neurons (15). Filopodia at early neuronal developmental stage neurons are just similar to those emerging from non-neuronal cells and do not show any morphological plasticity (33). Mature neurons have dendritic spines capable of morphological plasticity depending on synaptic activity, whereas immature neurons, cultured up to DIV7, have thin and long (filopodium-like) protrusions (12,13).…”