| 1. |
- Blomgren, Klas, 1963, et al.
(författare)
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Pathological apoptosis in the developing brain
- 2007
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Ingår i: Apoptosis. - : Springer Science and Business Media LLC. - 1360-8185 .- 1573-675X. ; 12:5, s. 993-1010
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Forskningsöversikt (refereegranskat)abstract
- More than half of the initially-formed neurons are deleted in certain brain regions during normal development. This process, whereby cells are discretely removed without interfering with the further development of remaining cells, is called programmed cell death (PCD). The term apoptosis is used to describe certain morphological manifestations of PCD. Many of the effectors of this developmental cell death program are highly expressed in the developing brain, making it more susceptible to accidental activation of the death machinery, e.g. following hypoxia-ischemia or irradiation. Recent evidence suggests, however, that activation and regulation of cell death mechanisms under pathological conditions do not exactly mirror physiological, developmentally regulated PCD. It may be argued that the conditions after e.g. ischemia are not even compatible with the execution of PCD as we know it. Under pathological conditions cells are exposed to various stressors, including energy failure, oxidative stress and unbalanced ion fluxes. This results in parallel triggering and potential overshooting of several different cell death pathways, which then interact with one another and result in complex patterns of biochemical manifestations and cellular morphological features. These types of cell death are here called "pathological apoptosis," where classical hallmarks of PCD, like pyknosis, nuclear condensation and caspase-3 activation, are combined with non-PCD features of cell death. Here we review our current knowledge of the mechanisms involved, with special focus on the potential for therapeutic intervention tailored to the needs of the developing brain.
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| 2. |
- Groc, L., et al.
(författare)
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AMPA signalling in nascent glutamatergic synapses: there and not there!
- 2006
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Ingår i: Trends in neurosciences. - : Elsevier BV. - 0166-2236. ; 29:3, s. 132-9
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Forskningsöversikt (refereegranskat)abstract
- Nascent glutamatergic synapses are thought to be equipped with only NMDA receptors and to mature in a stepwise fashion when AMPA receptors are acquired later, through specific patterns of activity. We review recent data suggesting that AMPA receptors are in fact present in the nascent synapse but in a labile state. The nascent synapse can easily switch between AMPA-signalling and AMPA-silent states in a manner not requiring activation of NMDA receptors or metabotropic glutamate receptors. NMDA receptor activation by correlated presynaptic and postsynaptic activity can switch the nascent synapse to a mature, more stable state, in which AMPA receptor signalling is modified only through conventional plasticity processes. Thus, the AMPA receptor silence of nascent glutamatergic synapses depends on the synaptic activation history rather than on the nascent state itself.
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