Polypeptoid polymers: Synthesis, characterization, and properties.

Polypeptoids, a class of peptidomimetic polymers, have emerged at the forefront of macromolecular and supramolecular science and engineering as the technological relevance of these polymers continues to be demonstrated. The chemical and structural diversity of polypeptoids have enabled access to and adjustment of a variety of physicochemical and biological properties (eg, solubility, charge characteristics, chain conformation, HLB, thermal processability, degradability, cytotoxicity and immunogenicity). These attributes have made this synthetic polymer platform a potential candidate for various biomedical and biotechnological applications.

Cationic Polypeptoids with Optimized Molecular Characteristics toward Efficient Nonviral Gene Delivery.

The rational design of gene vectors relies on the understanding of their structure-property relationship. Polypeptoids, which are structural isomers of natural polypeptides, hold great potential as gene delivery vectors due to their facile preparation, structural tunability, and most importantly, their desirable proteolytic stability. We herein designed a library of polypeptoids with different cationic side-chain terminal groups, degree of polymerizations (DPs), side-chain lengths, and incorporated aliphatic side chains, to unravel the structure-property relationships so that gene delivery efficiency can be maximized and cytotoxicity can be minimized.

YAC128 Huntington's disease transgenic mice show enhanced short-term hippocampal synaptic plasticity early in the course of the disease.

Huntington's disease (HD) is a progressive and fatal neurodegenerative disorder caused by a polyglutamine expansion in the gene encoding the protein huntingtin. The disease progresses over decades, but often patients develop cognitive impairments that precede the onset of the classical motor symptoms. Similar to the disease progression in humans, the yeast artificial chromosome (YAC) 128 HD mouse model also exhibits cognitive dysfunction that precedes the onset of the neuropathological and motor impairments characteristic of HD.

Hippocampal neurogenesis levels predict WATERMAZE search strategies in the aging brain.

The hippocampus plays a crucial role in the formation of spatial memories, and it is thought that adult hippocampal neurogenesis may participate in this form of learning. To better elucidate the relationship between neurogenesis and spatial learning, we examined both across the entire life span of mice. We found that cell proliferation, neuronal differentiation, and neurogenesis significantly decrease with age, and that there is an abrupt reduction in these processes early on, between 1.

Neurogenesis in Huntington's disease: can studying adult neurogenesis lead to the development of new therapeutic strategies?

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by an unstable expansion of CAG repeats in the HD gene. The symptoms include cognitive dysfunction and severe motor impairments. The neuropathology is characterized by neuronal loss mainly in the striatum and cortex, although other regions including the hippocampus are also affected.

Altered adult hippocampal neurogenesis in the YAC128 transgenic mouse model of Huntington disease.

Perturbations in neurogenesis in the adult brain have been implicated in impaired learning and memory. In the present study, we investigated which stages of the neurogenic process are affected in the transgenic YAC128 mouse model of Huntington disease (HD). Hippocampal neuronal proliferation was altered in the dentate gyrus (DG) of YAC128 mice as compared with wild-type (WT) littermate controls in early symptomatic to end-stage mice.

Characterization of the neurogenesis quiescent zone in the rodent brain: effects of age and exercise.

Although it is accepted that new neurons continue to be generated in the hippocampal dentate gyrus (DG) throughout adulthood, it has recently become apparent that this process is not homogeneous, and that a small region of the DG lacks neurogenesis. Here, we show that the relative area of this neurogenesis quiescent zone (NQZ) did not vary after the peak in hippocampal postnatal neurogenesis and until animals reached adulthood, although the ratio between its actual volume and the total volume of the DG doubled during this time. However, we were able to identify a few mitotic cells that reside within this subregion in early adolescent rats.

Running reduces stress and enhances cell genesis in aged mice.

Cell proliferation and neurogenesis are diminished in the aging mouse dentate gyrus. However, it is not known whether isolated or social living affects cell genesis and stress levels in old animals. To address this question, aged (17-18 months old) female C57Bl/6 mice were single or group housed, under sedentary or running conditions.