Search results for " Plasticity"

Synaptopodin regulates denervation-induced homeostatic synaptic plasticity

2013

Synaptopodin (SP) is a marker and essential component of the spine apparatus (SA), an enigmatic cellular organelle composed of stacked smooth endoplasmic reticulum that has been linked to synaptic plasticity. However, SP/SA-mediated synaptic plasticity remains incompletely understood. To study the role of SP/SA in homeostatic synaptic plasticity we here used denervation-induced synaptic scaling of mouse dentate granule cells as a model system. This form of plasticity is of considerable interest in the context of neurological diseases that are associated with the loss of neurons and subsequent denervation of connected brain regions. In entorhino-hippocampal slice cultures prepared from SP-de…

A common thread for pain and memory synapses? Brain-derived neurotrophic factor and trkB receptors.

2003

Recent evidence indicates that trophic factors can exert fast effects on neurones and so alter synaptic plasticity. Here, we focus on brain-derived neurotrophic factor (BDNF), which exerts a modulatory action at hippocampal synapses that are involved in learning and memory, and at the first pain synapse between primary sensory neurones and dorsal horn neurones. Hippocampal and sensory neurones share some properties for the release of endogenous BDNF. In the Schaffer collateral pathway of the hippocampus, binding of BDNF to high-affinity trkB receptors is essential for the induction of long-term potentiation, a specific type of synaptic plasticity. However, the consequences of BDNF binding t…

Endocannabinoid signals in the control of emotion.

2008

The appropriate control of emotional responses evoked by environmental stimuli is an important innate mechanism for ensuring quality of life and even for survival. Inappropriate responses and decreased abilities to adjust to changed environmental situations can lead to psychiatric disorders, such as posttraumatic stress disorders, phobia and depression. Endocannabinoid signalling has emerged as one of the regulatory systems of the brain supporting appropriate emotional responses. As various components of the endocannabinoid system have become therapeutic targets, understanding the endocannabinoids’ mechanism of action is an important research topic for a rationalized drug design and optimal…

DOES ENVIRONMENTAL ROBUSTNESS PLAY A ROLE IN FLUCTUATING ENVIRONMENTS?

2013

Fluctuating environments are expected to select for individuals that have highest geometric fitness over the experienced environments. This leads to the prediction that genetically determined environmental robustness in fitness, and average fitness across environments should be positively genetically correlated to fitness in fluctuating environments. Because quantitative genetic experiments resolving these predictions are missing, we used a full-sib, half-sib breeding design to estimate genetic variance for egg-to-adult viability in Drosophila melanogaster exposed to two constant or fluctuating temperatures that were above the species' optimum temperature, during development. Viability in t…

Bet-hedging in diapausing egg hatching of temporary rotifer populations - A review of models and new insights

2014

Habitat unpredictability is a local adaptation factor shaping life-history traits in rotifer populations. It may select for the evolution of bet-hedging through risk-spreading strategies in diapausing egg hatching. This means that a fraction of diapausing eggs in wild populations do not hatch even when the conditions are favorable for population growth. Thus, there is a remaining fraction of viable diapausing eggs standing in the sediments for longer periods. According to theory, it is expected that the incidence of bet-hedging strategies for diapausing egg hatching will be higher in more uncertain habitats. Here, we review the major predictions derived from theoretical models applied to th…

From foes to friends: Viral infections expand the limits of host phenotypic plasticity

2020

Phenotypic plasticity enables organisms to survive in the face of unpredictable environmental stress. Intimately related to the notion of phenotypic plasticity is the concept of the reaction norm that places phenotypic plasticity in the context of a genotype-specific response to environmental gradients. Whether reaction norms themselves evolve and which factors might affect their shape has been the object of intense debates among evolutionary biologists along the years. Since their discovery, viruses have been considered as pathogens. However, new viromic techniques and a shift in conceptual paradigms are showing that viruses are mostly non-pathogenic ubiquitous entities. Recent studies hav…

Profiling the diversity of innate lymphoid cells

2015

Genome-wide transcriptional profiling of tissue-resident innate lymphoid cells (ILCs) has provided important insight not only into their developmental relationships and phenotypic plasticity but also into previously unknown functions.

Influence of temperature and photoperiod on embryonic development in the dragonflySympetrum striolatum(Odonata: Libellulidae)

2015

Temperature and photoperiod play major roles in insect ecology. Many insect species have fixed degree-days for embryogenesis, with minimum and maximum temperature thresholds for egg and larval development and hatching. Often, photoperiodic changes trigger the transfer into the next life-cycle stadium. However, it is not known whether this distinct pattern also exist in a species with a high level of phenotypic plasticity in life-history traits. In the present study, eggs of the dragonfly Sympetrum striolatum Charpentier (Odonata: Libellulidae) are reared under different constant and fluctuating temperatures and photoperiodic conditions in several laboratory and field experiments. In general…

The genetics of phenotypic plasticity in livestock in the era of climate change: a review

2020

Climate change has the potential to adversely affect the health of livestock, with consequences to animal welfare, greenhouse gas emissions, productivity, human health and livelihoods. Phenotypic plasticity is the ability of a genotype to produce different phenotypes, depending on environmental, biotic or abiotic conditions; it is a factor influencing and modifying the genes of animal and plant organisms, to adaptation to climate change. Among the various climate variables, heat stress has been reported to be the most detrimental factor to the economy of the livestock industry. There are a number of candidate genes that are associated with adaptation of ruminants, monogastric and poultry to…

2021

Interactions between organisms and their environments are central to how biological diversity arises and how natural populations and ecosystems respond to environmental change. These interactions involve processes by which phenotypes are affected by or respond to external conditions (e.g., via phenotypic plasticity or natural selection) as well as processes by which organisms reciprocally interact with the environment (e.g., via eco-evolutionary feedbacks). Organism-environment interactions can be highly dynamic and operate on different hierarchical levels, from genes and phenotypes to populations, communities, and ecosystems. Therefore, the study of organism-environment interactions requir…