Developmental plasticity

About: Developmental plasticity is a research topic. Over the lifetime, 1721 publications have been published within this topic receiving 103438 citations.

AMPA Receptor Phosphorylation in Synaptic Plasticity: Insights from Knockin Mice

Abstract: Synaptic plasticity in the brain has been implicated to play a role in major brain functions, including learning and memory, developmental plasticity, recovery after injury and drug addiction. The current understanding of the mechanisms of synaptic plasticity derives from molecular and cellular analysis of long-term potentiation (LTP) and long-term depression (LTD). LTP and LTD are readily elicited from many brain regions with different induction and expression mechanisms. At least two different induction mechanisms for LTP and LTD exist, one that depends on activation of N-methyl-D-aspartate (NMDA) receptors and another that does not. The expression of NMDA receptor-dependent and receptor-independent LTP and LTD seem to have overlapping but different signalling mechanisms [1]. Most of the molecular details on NMDA receptor-dependent LTP and LTD have come from studies in the CA1 region of the hippocampus. At least in this region of the brain, regulation of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors seems to underlie post-synaptic changes associated with NMDA receptor-dependent LTP and LTD. Especially, evidence exists that changes in AMPA receptor phosphorylation is one of the mechanisms critical for the expression of NMDA receptor-dependent bidirectional synaptic plasticity.This review will summarize the recent findings from our work using gene “knockin” mice lacking specific phosphorylation sites on the GluR1 subunit of AMPA receptors, and discuss the implications of our results that elucidate the basic mechanisms of NMDA receptor-dependent synaptic plasticity.

Homeostasis and Learning through Spike-Timing Dependent Plasticity

Abstract: Synaptic plasticity is thought to be the neuronal correlate of learning. Moreover, modification of synapses contributes to the activity-dependent homeostatic maintenance of neurons and neural networks. In this chapter, we review theories of synaptic plasticity and show that both homeostatic control of activity and detection of correlations in the presynaptic input can arise from spike-timing dependent plasticity (STDP). Relations to classical rate-based Hebbian learning are discussed.

Exposure to sublethal concentrations of a pesticide or predator cues induces changes in brain architecture in larval amphibians

Abstract: Naturally occurring environmental factors shape developmental trajectories to produce variable phenotypes. Such developmental phenotypic plasticity can have important effects on fitness, and has been demonstrated for numerous behavioral and morphological traits. However, surprisingly few studies have examined developmental plasticity of the nervous system in response to naturally occurring environmental variation, despite accumulating evidence for neuroplasticity in a variety of organisms. Here, we asked whether the brain is developmentally plastic by exposing larval amphibians to natural and anthropogenic factors. Leopard frog tadpoles were exposed to predator cues, reduced food availability, or sublethal concentrations of the pesticide chlorpyrifos in semi-natural enclosures. Mass, growth, survival, activity, larval period, external morphology, brain mass, and brain morphology were measured in tadpoles and after metamorphosis. Tadpoles in the experimental treatments had lower masses than controls, although developmental rates and survival were similar. Tadpoles exposed to predator cues or a high dose of chlorpyrifos had altered body shapes compared to controls. In addition, brains from tadpoles exposed to predator cues or a low dose of chlorpyrifos were narrower and shorter in several dimensions compared to control tadpoles and tadpoles with low food availability. Interestingly, the changes in brain morphology present at the tadpole stage did not persist in the metamorphs. Our results show that brain morphology is a developmentally plastic trait that is responsive to ecologically relevant natural and anthropogenic factors. Whether these effects on brain morphology are linked to performance or fitness is unknown.

Epigenetics and developmental plasticity in orthopteroid insects.

Abstract: Developmental plasticity is a key driver of the extraordinary ecological success of insects. Epigenetic mechanisms provide an important link between the external stimuli that initiate polyphenisms, and the stable changes in gene expression that govern alternative insect morphs. We review the epigenetics of orthopteroid insects, focussing on recent research on locusts and termites, two groups which display high levels of phenotypic plasticity, and for which genome sequences have become available in recent years. We examine research on the potential role of DNA methylation, histone modifications, and non-coding RNAs in the regulation of gene expression in these insects. DNA methylation patterns in orthopteroids share a number of characteristics with those of hymenopteran insects, although methylation levels are much higher, and extend to introns and repeat elements. Future examinations of epigenetic mechanisms in these insects will benefit from comparison of tissues from aged-matched individuals from alternative morphs, and adequate biological replication.