Dendritic spine

Neurodegeneration. Figure 3 Illustration of synaptic (neuritic) apoptosis. A pyramidal neuron is depicted with cortical afferents synapsing on its dendrites. Localized apoptotic mechanisms lead to the release of cytochrome c from the mitochondria and an increase in the concentration of activated caspase-3 in a presynaptic terminal that is synapsing on a dendritic spine. Increased caspase-3 activity results in a localized breakdown of this nerve terminal and its synapse. Subsequently, the postsynaptic dendritic spine retracts and disappears (Figure modified from Glantz et al. [5] [3]). 

Saez ET, Pehar M, Vargas MR, Barbeito L, Maccioni RB (2006) Production of nerve growth factor by beta-amyloid-stimulated astrocytes induces p75NTR-dependent tau hyperphosphorylation in cultured hippocampal neurons. J Neurosci Res 84 1098-1106 Sala C, Roussignol G, Meldolesi J, Fagni L (2005) Key role of the postsynaptic density scaffold proteins Shank and Homer in the functional architecture of Ca homeostasis at dendritic spines in hippocampal neurons. J Neurosci 25 4587 592 Santello M, Volterra A (2008) Synaptic modulation by astrocytes via Ca(2-l-)-dependent glutamate release. Neuroscience 158 253-9... 

Fig. 5.12 (a) Synaptic types along dendritic spines of M/T and GC units uni-, and bi-directional junctions, (b) Transmitter systems at a reciprocal synapse, Mitral-Granule cell junction. [Glu, glutamate (R, receptor) GABA, y-aminobutyric acid (R, receptor) E, intracellular effector and aAR, alpha-adrenergic receptor.]. (From Hayashi et al., 1993.)... 

Decreased numbers of dendritic spines and malformed spines in brain parietal cortex were observed at postnatal day 30 in rat pups whose mothers were administered 256-480 mg lead/kg/day as lead acetate in drinking water during gestation and lactation (Murray et al. 1978). PbB levels were not reported. 

Ouimet, C.C., daCruz, E., Silva, E.F., Greengard, P. The alpha and gamma 1 isoforms of protein phosphatase 1 are highly and specifically concentrated in dendritic spines. Proc. Natl. Acad. Sci. U.S.A. 92 3396, 1995. 

Nakayama AY, Luo L. Small GTPases Rac and Rhoin the maintenance of dendritic spines and branches in hippocampal pyramidal neuronsi. J Neurosci 2000 20 5329-5338. 

To perform its unique functional role each neuron must regulate a host of intracellular activities, that occur in axons and dendrites distant from the cell nucleus. For example, axonal guidance during development, or remodeling of dendritic spines in response to local input, each involves many different complex control systems that are highly localized and largely autonomous. [ 1 ]. 

Smiley, J. F., Levey, A. I., Ciliax, B. J. and Goldman-Rakic, P. S. D1 dopamine receptor immunoreactivity in human and monkey cerebral cortex predominant and extrasynaptic localization in dendritic spines. Proc. Natl Acad. Sci. U.S.A. 91 5720-5724,1994. 

DENDRITIC SPINES ARE MOTILE, CHANGING THEIR SHAPE AND SIZE IN RESPONSE TO SYNAPTIC ACTIVITY WITHIN MINUTES 286... 

The NR2 subunit of the NMDA receptor binds to PDZ domains of PSD95 with its cytoplasmic C-terminus. PSD95 also binds a-actinin, which again binds to filamentous actin (F-actin), a main cytoskeletal protein in dendritic spines. In this manner PSD95 anchors the NMDA receptor to the cytoskeleton of the dendritic spine. 

Hering, H., Lin, C. C. and Sheng, M. Lipid rafts in the maintenance of synapses, dendritic spines, and surface AMPA receptor stability. /. Neurosci. 23 3262-3271, 2003. 

Sala, C., Piech, V., Wilson, N. R. et al. Regulation of dendritic spine morphology and synaptic function by Shank and Homer. Neuron 31 115-130, 2001. 

Passafaro, M., Nakagawa, T., Sala, C. and Sheng, M. Induction of dendritic spines by an extracellular domain of AMPA receptor subunit GluR2. Nature 424 677-681, 2003. 

The adult brain is endowed with nuclear as well as cytosolic and membrane T3 receptors that have been visualized by autoradiography and studied biochemically [30-33]. Both neurons and neuropil are labeled by [ 1251]T3, and the labeling is selective across brain regions. Functionally, one of the most prominent features of neural action of thyroid hormone in adulthood is subsensitivity to norepinephrine as a result of a hypothyroid state [27], These changes may be reflections of loss of dendritic spines in at least some neurons of the adultbrain. Clinically, thyroid hormone deficiency increases the probability of depressive illness, whereas thyroid excess increases the probability of mania (Ch. 52) in susceptible individuals [27],... 

Persistent adaptations may involve changes in the structure of dendrites and dendritic spines 924... 

Lujan, R., Nusser, Z., Roberts, J. D., Shigemoto, R and Somogyi, P. (1996) Perisynaptic location of metabotropic glutamate receptors mGluRl and mGluR5 on dendrites and dendritic spines in the rat hippocampus. Eur. J. Neurosci. 8,1488-1500. 

Wallhauser, E. and Scheich, H. (1987) Auditory imprinting leads to differential 2-deoxy-glucose uptake and dendritic spine loss in the chick rostral forebrain. Develop. Brain Res. 31, 29-44. 

Ji, Y., Gong, Y., Gan, W., Beach, T., Holtzman, D.M., Wisniewski, T. (2003) Apolipoprotein E isoform-specific regulation of dendritic spine morphology in apolipoprotein E mice and Alzheimer s disease patients. Neuroscience, 122, 305-315. 

Dendritic spine a small sac of membrane that protrudes from the dendrites of some cells and receives synaptic input. 

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