Regulation of physiological homeostasis, including energy balance, is thought to be modified by low levels of adult neurogenesis in the hypothalamus. Hormones such as oestradiol can influence both embryonic and adult hypothalamic neurogenic programs, demonstrating a sensitivity of hypothalamic neural progenitor cells to endogenous hormones. Previously we showed that gestational exposure to environmental levels of the xenoestrogen bisphenol A (BPA) changed neural progenitor cell behaviors in the embryo; however, we did not examine if these changes were permanent to affect adult neurogenesis.
View Article and Find Full Text PDFThe ability of the mammalian brain to maintain spatial representations of external or internal information for short periods of time has been associated with sustained neuronal spiking and reverberatory neural network activity in the medial entorhinal cortex. Here, we show that conditional genetic deletion of netrin-1 or the netrin receptor deleted-in-colorectal cancer (DCC) from forebrain excitatory neurons leads to deficits in short-term spatial memory. We then demonstrate that conditional deletion of either netrin-1 or DCC inhibits cholinergic persistent firing and show that cholinergic activation of muscarinic receptors expressed by entorhinal cortical neurons promotes persistent firing by recruiting DCC to the plasma membrane.
View Article and Find Full Text PDFRoad pavement condition assessment is essential for maintenance, asset management, and budgeting for pavement infrastructure. Countries allocate a substantial annual budget to maintain and improve local, regional, and national highways. Pavement condition is assessed by measuring several pavement characteristics such as roughness, surface skid resistance, pavement strength, deflection, and visual surface distresses.
View Article and Find Full Text PDFCritical physiological processes such as sleep and stress that underscore health are regulated by an intimate interplay between the endocrine and nervous systems. Here, we asked how fetal exposure to the endocrine disruptor found in common plastics, bisphenol A (BPA), causes lasting effects on adult animal behaviors. Adult mice exposed to low-dose BPA during gestation displayed notable disruption in circadian activity, social interactions, and associated neural hyperactivity, with some phenotypes maintained transgenerationally.
View Article and Find Full Text PDFJ Acquir Immune Defic Syndr Hum Retrovirol
November 1998
This study compared the baseline sociodemographic characteristics and HIV risk behaviors of two groups of out-of-treatment injection drug users (IDUs): 366 who concurrently smoked crack (smoking IDUs) and 212 who did not smoke crack (IDUs) in the past 30 days. Temporal trends in recent risk behaviors were also assessed for each drug user group over an 18-month period, January 1992 through June 1994. Baseline data were collected in South Philadelphia before the implementation of a multisite HIV intervention research project funded by the National Institute on Drug Abuse.
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