Structural and functional plasticity of dendritic spines – root or result of behavior?

Abstract

Dendritic spines are multifunctional integrative units of the nervous system and are highly diverse and dynamic in nature. Both internal and external stimuli influence dendritic spine density and morphology on the order of minutes. It is clear that the structural plasticity of dendritic spines is related to changes in synaptic efficacy, learning and memory, and other cognitive processes. However, it is currently unclear whether structural changes in dendritic spines are primary instigators of changes in specific behaviors, a consequence of behavioral changes, or both. In this review, we first review the basic structure and function of dendritic spines in the brain, as well as laboratory methods to characterize and quantify morphological changes in dendritic spines. We then discuss the existing literature on the temporal and functional relationship between changes in dendritic spines in specific brain regions and changes in specific behaviors mediated by those regions. Although technological advancements have allowed us to better understand the functional relevance of structural changes in dendritic spines that are influenced by environmental stimuli, the role of spine dynamics as an underlying driver or consequence of behavior still remains elusive. We conclude that while it is likely that structural changes in dendritic spines are both instigators and results of behavioral changes, improved research tools and methods are needed to experimentally and directly manipulate spine dynamics in order to more empirically delineate the relationship between spine structure and behavior.

Rac1 is a downstream effector of PKCα in structural synaptic plasticity

“…1b,c). This structural plasticity is associated with an increase in the functional strength of the stimulated spine (Gipson and Olive, 2017;Matsuzaki et al, 2004). Consistent with previous work, hippocampal CA1 neurons from PKCα knockout mice showed a deficit in sLTP regardless of sensor expression ( Fig.…”

Neurotoxicity in Preclinical Models of Occupational Exposure to Organophosphorus Compounds

“…Changes in hippocampal neuron numbers were not apparent at either the 1-week or 3-month time points. It is well known that morphological plasticity of both axons and dendrites are critical for the behaviors discussed above (Leuner and Gould, 2010; Marsden, 2013; Gipson and Olive, 2016). Therefore, it is possible that these changes could also occur in occupational OP exposures and contribute to neurobehavioral deficits.…”

Geometric principles of second messenger dynamics in dendritic spines

“…We next investigated the effect of the shape of the spine and the spine apparatus. This is particularly relevant since dendritic spines are known to have distinct shapes and their shape is associated with function [22,30,31]. Because the shape of the spine is a result of many different geometric properties, we focused specifically on curvature by modeling the spine shapes as different ellipsoidal shells.…”

“…Changes in dendritic spine shape and density are symptomatic of several neuropathologies and neurodegenerative diseases such as Alzheimer's, Parkinson's, and drug addiction [25][26][27][28][29]. Thus, it is believed that the morphology of spines is closely related to their function: in fact, reciprocal changes between the structure and function of spines impact both local and global integration of signals within dendrites [22,[30][31][32]. Recently, Ramirez et al [33] proposed that a combination of the geometry of dendritic spines and a characteristic propagation of Cdc42 induce localization of the protein in a timescale longer than the one estimated from the diffusion timescale alone.…”