Many types of specialized plasma membranes can separate cell from external environment: apical, basolateral, presynaptic and postsynaptic ones, membranes of flagella, cilia, microvillus, filopodia and lamellipodia, the sarcolemma of muscle cells, as well as specialized myelin and dendritic spine membranes of neurons.

This is where the majority of input to the neuron occurs via the dendritic spine.

Exposure to chronic stress leads to more profound working memory deficits and additional architectural changes in PFC, including dendritic atrophy and spine loss, which can be prevented by inhibition of protein kinase C signaling.

Evidence from mouse models shows that mGluR5 antagonists ( blockers ) can rescue dendritic spine abnormalities and seizures, as well as cognitive and behavioral problems, and may show promise in the treatment of FXS.

It also stimulates dendrite and dendritic spine development and regulates the continuing migration of neuroblasts generated in adult neurogenesis sites like subventricular and subgranular zones.

Reelin also plays an important role in the adult brain by modulating cortical pyramidal neuron dendritic spine expression density, the branching of dendrites, and the expression of long-term potentiation as its secretion is continued diffusely by the GABAegric cortical interneurons those origin is traced to the medial ganglionic eminence.

Considering the role of reelin in promoting dendritogenesis, suggestions were made that the localized dendritic spine deficit observed in schizophrenia could be in part connected with the downregulation of reelin.

* dendritic spine

A dendritic spine ( or spine ) is a small membranous protrusion from a neuron's dendrite that typically receives input from a single synapse of an axon.

Because dendritic spines are plastic structures whose lifespan is influenced by input activity, spine dynamics may play an important role in the maintenance of memory over a lifetime.

In youth, dendritic spine turnover is relatively high and produces a net loss of spines, with the rate of the elimination of spines surpassing the rate of the formation of spines.

Experience-induced changes in dendritic spine stability also point to spine turnover as a mechanism involved in the maintenance of long-term memories, though it is unclear how sensory experience affects neural circuitry.

In lab animals of all ages, environmental enrichment has been related to dendritic branching, spine density, and overall number of synapses.

Dendrites disintegrate and reassemble rapidly during ischemia — as with stroke, survivors showed an increase in dendritic spine turnover.

While a net loss of spines is observed in Alzheimer's disease and cases of mental retardation, cocaine and amphetamine use have been linked to increases in dendritic branching and spine density in the prefrontal cortex and the nucleus accumbens.

Despite experimental findings that suggest a role for dendritic spine dynamics in mediating learning and memory, the degree of structural plasticity ’ s importance remains debatable.

A dendritic spine has high input resistance, the resistance increases with smallness of headsize and narrowness of stemsize.

Because there is an impedance mismatch between the dendritic spine and the dendrite, it is necessary with active signal boosting.

Studies of dendritic spines, protruding structures on dendrites that physically grow and retract over the course of minutes or hours, have suggested a relationship between the electrical resistance of the spine and the effective synapse strength, due to their relationship with intracellular calcium transients.

Regardless of their identities, it is thought that they contribute to the increase in dendritic spine number, surface area, and postsynaptic sensitivity to neurotransmitter associated with L-LTP expression.

Activation of the second messenger pathway leads to increased levels of CaMKII and PKAII within the dendritic spine.

These protein kinases have been linked to growth in dendritic spine volume and LTP processes such as the addition of AMPA receptors to the plasma membrane and phosphorylation of ion channels for enhanced permeability.

Based on passive cable theory one can track how changes in a neuron ’ s dendritic morphology changes the membrane voltage at the soma, and thus how variation in dendrite architectures affects the overall output characteristics of the neuron.

Furthermore, a train of backpropagating action potentials artificially generated at the soma can induce a calcium action potential ( a dendritic spike ) at the dendritic initiation zone in certain types of neurons.

Neurons such as Purkinje cells in the cerebellum can have over 1000 dendritic branches, making connections with tens of thousands of other cells ; other neurons, such as the magnocellular neurons of the supraoptic nucleus, have only one or two dendrites, each of which receives thousands of synapses.

Jasper can be modified by the diffusion of minerals along discontinuities providing the appearance of vegetative growth, i. e., dendritic.

Stephen Smith and colleagues have shown that contact initiated by dendritic filopodia can develop into synapses.

Unmethylated CpG sites can be detected by Toll-Like Receptor 9 ( TLR 9 ) on plasmacytoid dendritic cells and B cells in humans.

MHC class II can be conditionally expressed by all cell types, but normally occurs only on professional antigen-presenting cells ( APCs ): macrophages, B cells, and especially dendritic cells ( DCs ).

It is known that the murine parasites can infect, survive and replicate within plasmacytoid dendritic cells of the spleen and that these infections may be productive.

Typically, rias have a dendritic, treelike outline although they can be straight and without significant branches.

The co-stimulation of the B cell can come from another antigen presenting cell, like a dendritic cell.

Dendritic spines can develop directly off of dendritic shafts or from dendritic filopodia.

Branched hairs can be dendritic ( tree-like ), tufted, or stellate ( star-shaped ).

Negative environmental influences have a direct effect on all areas of neurodevelopment: neurogenesis ( creation of new neurons ), apoptosis ( death and reabsorption of neurons ), migration ( of neurons to different regions of the brain ), synaptogenesis ( creation of synapses ), synaptic sculpturing ( determining the make-up of the synapse ), arborization ( the growth of dendritic connections, myelinzation ( protective covering of neurons ), and an enlargement of the brain's ventricles, which can cause cortical atrophy.

This activation is localized to spines with focal stimulation and is inactivated before spreading to adjacent spines or the shaft, indicating an important mechanism of LTP in that particular changes in protein activation can be localized or compartmentalized to enhance the responsivity of single dendritic spines.

After phagocytosis, macrophages and dendritic cells can also participate in antigen presentation, a process in which a phagocyte moves parts of the ingested material back to its surface.

The source of interferon-gamma can be CD4 < sup >+</ sup > T cells, CD8 < sup >+</ sup > T cells, natural killer cells, B cells, natural killer T cells, monocytes, macrophages, or dendritic cells.

Mature macrophages do not travel far from the site of infection, but dendritic cells can reach the body's lymph nodes where there are millions of lymphocytes.

But dendritic cells can also destroy or pacify lymphocytes if they recognize components of the host body ; this is necessary to prevent autoimmune reactions.

In addition, dendritic cells can influence the type of immune response produced ; when they travel to the lymphoid areas where T cells are held they can activate T cells, which then differentiate into cytotoxic T cells or helper T cells.