Nature reviews. Neuroscience
-
The division of cortical visual processing into distinct dorsal and ventral streams is a key framework that has guided visual neuroscience. The characterization of the ventral stream as a 'What' pathway is relatively uncontroversial, but the nature of dorsal stream processing is less clear. ⋯ Here, we identify three pathways emerging from the dorsal stream that consist of projections to the prefrontal and premotor cortices, and a major projection to the medial temporal lobe that courses both directly and indirectly through the posterior cingulate and retrosplenial cortices. These three pathways support both conscious and non-conscious visuospatial processing, including spatial working memory, visually guided action and navigation, respectively.
-
Nat. Rev. Neurosci. · Feb 2011
ReviewAmyloid-β and tau--a toxic pas de deux in Alzheimer's disease.
Amyloid-β and tau are the two hallmark proteins in Alzheimer's disease. Although both amyloid-β and tau have been extensively studied individually with regard to their separate modes of toxicity, more recently new light has been shed on their possible interactions and synergistic effects in Alzheimer's disease. Here, we review novel findings that have shifted our understanding of the role of tau in the pathogenesis of Alzheimer's disease towards being a crucial partner of amyloid-β. As we gain a deeper understanding of the different cellular functions of tau, the focus shifts from the axon, where tau has a principal role as a microtubule-associated protein, to the dendrite, where it mediates amyloid-β toxicity.
-
Nat. Rev. Neurosci. · Dec 2010
Functions of Nogo proteins and their receptors in the nervous system.
The membrane protein Nogo-A was initially characterized as a CNS-specific inhibitor of axonal regeneration. Recent studies have uncovered regulatory roles of Nogo proteins and their receptors--in precursor migration, neurite growth and branching in the developing nervous system--as well as a growth-restricting function during CNS maturation. The function of Nogo in the adult CNS is now understood to be that of a negative regulator of neuronal growth, leading to stabilization of the CNS wiring at the expense of extensive plastic rearrangements and regeneration after injury. In addition, Nogo proteins interact with various intracellular components and may have roles in the regulation of endoplasmic reticulum (ER) structure, processing of amyloid precursor protein and cell survival.
-
Nat. Rev. Neurosci. · Aug 2010
ReviewSleep and circadian rhythm disruption in psychiatric and neurodegenerative disease.
Sleep and circadian rhythm disruption are frequently observed in patients with psychiatric disorders and neurodegenerative disease. The abnormal sleep that is experienced by these patients is largely assumed to be the product of medication or some other influence that is not well defined. ⋯ We propose that brain disorders and abnormal sleep have a common mechanistic origin and that many co-morbid pathologies that are found in brain disease arise from a destabilization of sleep mechanisms. The stabilization of sleep may be a means by which to reduce the symptoms of--and permit early intervention of--psychiatric and neurodegenerative disease.
-
Nat. Rev. Neurosci. · Jul 2010
ReviewA model for memory systems based on processing modes rather than consciousness.
Prominent models of human long-term memory distinguish between memory systems on the basis of whether learning and retrieval occur consciously or unconsciously. Episodic memory formation requires the rapid encoding of associations between different aspects of an event which, according to these models, depends on the hippocampus and on consciousness. ⋯ Consciousness seems to be a poor criterion for differentiating between declarative (or explicit) and non declarative (or implicit) types of memory. A new model is therefore required in which memory systems are distinguished based on the processing operations involved rather than by consciousness.