No abstract

To assess the possible role of trophic factors in lesion-induced plasticity, we have used a sensitive immunohistochemical technique to evaluate changes in nerve growth factor (NGF) staining in the hippocampal formation 3, 8, 16, and 30 days following entorhinal cortex lesions. Our results indicate that a band of NGF immunoreactivity appears in the outer molecular layer of the ipsilateral dentate gyrus following entorhinal ablation. The distribution of the NGF-immunoreactive band exactly coincides with the distribution of sprouting cholinergic terminals revealed by acetylcholinesterase histochemistry or NGF-receptor immunostaining. Increased NGF-immunoreactivity is detectable at 3 days postlesion, is most intense at 8 days, and decreases to near control levels by 30 days. Lesion-induced increases in NGF immunostaining also occur in animals in which septohippocampal fibers had been removed by prior destruction of the fimbria-fornix. Increases in NGF-immunoreactivity, however, are substantially reduced in animals receiving intraventricular injections of colchicine, which presumably blocks NGF release. These results indicate that 1) increases in NGF immunostaining, which occur following entorhinal lesions, precede any changes in cholinergic sprouting parameters and are greatest during the period of maximal cholinergic sprouting; 2) increased NGF-immunoreactivity is not due to NGF binding by septohippocampal fibers; and 3) increased NGF-immunoreactivity appears to depend on the release of NGF by neurons that produce it. We hypothesize that, following entorhinal lesions, NGF immunostaining within the hippocampal formation may represent NGF "anchored" within the tissue and that NGF accumulation by such a mechanism may direct the sprouting response of NGF-sensitive cholinergic neurons.

No abstract

No abstract

How many international students are reported for academic integrity violations (AIV), what are their demographics, and how do AIV sanctions affect their retention and/or graduation? Descriptive statistical analyses showed that the number of internationals reported for AIVs at an American West Coast public university increased almost six-fold between academic years 2009–10 and 2013–14. However, that number represented less than 7.5% of these students’ total enrollment. Among reported ones, undergraduates outnumbered graduate students, males outnumbered females, Chinese outnumbered other nationalities, Economics majors outnumbered other majors, and the most common AIV was exam misconduct. More than half who were reported and suspended for AIVs graduated and/or were retained. These findings’ administrative, policy, and theoretical implications are discussed.