PMC:2944628 / 1330-3062 JSONTXT

{"project":"TEST0","denotations":[{"id":"20877422-54-62-264424","span":{"begin":290,"end":294},"obj":"[\"15118105\"]"},{"id":"20877422-78-86-264425","span":{"begin":314,"end":318},"obj":"[\"16371948\"]"},{"id":"20877422-166-174-264426","span":{"begin":774,"end":778},"obj":"[\"14614143\"]"},{"id":"20877422-117-125-264427","span":{"begin":1077,"end":1081},"obj":"[\"12859354\"]"},{"id":"20877422-139-147-264428","span":{"begin":1099,"end":1103},"obj":"[\"12640670\"]"},{"id":"20877422-221-229-264429","span":{"begin":1403,"end":1407},"obj":"[\"16421862\"]"},{"id":"20877422-235-243-264430","span":{"begin":1503,"end":1507},"obj":"[\"18509506\"]"},{"id":"20877422-228-236-264431","span":{"begin":1526,"end":1530},"obj":"[\"18758458\"]"},{"id":"20877422-234-242-264432","span":{"begin":1551,"end":1555},"obj":"[\"19181621\"]"},{"id":"20877422-168-176-264434","span":{"begin":1726,"end":1730},"obj":"[\"20487030\"]"}],"text":"The functional role of adult neurogenesis in the hippocampal dentate gyrus remains controversial. Dentate gyrus as a whole is thought to be strongly related to cognitive decline in old age but the exact contribution of neurogenesis vs. other forms of plasticity is uncertain (Small et al., 2004; Burke and Barnes, 2006). There is convincing evidence that experimentally-induced decline in neurogenesis produces severe impairments in performance on some but not all memory tasks (Deng et al., 2010). Studies attempting to correlate natural decline of neurogenesis and memory with age have been controversial. In one such study, a sub-population of old (20 months) rats showed cognitive impairment in correlation with the number of adult-produced new neurons (Drapeau et al., 2003). Interestingly, old unimpaired rats performed nearly as well as the young (2 months) rats even though the former had only a fraction of the new neurons in comparison to the young. Other studies failed to demonstrate a relationship between neurogenesis and memory performance (Bizon and Gallagher, 2003; Merrill et al., 2003). Methodological reasons may account for these discrepancies between studies. For example, it would appear that spatial memory tasks may not be optimal for testing the influence of neurogenesis since many studies failed to demonstrate a clear cause-effect relationship in such tasks (Leuner et al., 2006) while others produced varied effects on either short-term or long-term memory (Dupret et al., 2008; Imayoshi et al., 2008; Jessberger et al., 2009). Species differences should also be considered since neurogenesis varies in its rate and physiological significance among species (Snyder et al., 2009a; Johnson et al., 2010)."}

{"project":"2_test","denotations":[{"id":"20877422-15118105-38206136","span":{"begin":290,"end":294},"obj":"15118105"},{"id":"20877422-16371948-38206137","span":{"begin":314,"end":318},"obj":"16371948"},{"id":"20877422-14614143-38206138","span":{"begin":774,"end":778},"obj":"14614143"},{"id":"20877422-12859354-38206139","span":{"begin":1077,"end":1081},"obj":"12859354"},{"id":"20877422-12640670-38206140","span":{"begin":1099,"end":1103},"obj":"12640670"},{"id":"20877422-16421862-38206141","span":{"begin":1403,"end":1407},"obj":"16421862"},{"id":"20877422-18509506-38206142","span":{"begin":1503,"end":1507},"obj":"18509506"},{"id":"20877422-18758458-38206143","span":{"begin":1526,"end":1530},"obj":"18758458"},{"id":"20877422-19181621-38206144","span":{"begin":1551,"end":1555},"obj":"19181621"},{"id":"20877422-20487030-38206146","span":{"begin":1726,"end":1730},"obj":"20487030"}],"text":"The functional role of adult neurogenesis in the hippocampal dentate gyrus remains controversial. Dentate gyrus as a whole is thought to be strongly related to cognitive decline in old age but the exact contribution of neurogenesis vs. other forms of plasticity is uncertain (Small et al., 2004; Burke and Barnes, 2006). There is convincing evidence that experimentally-induced decline in neurogenesis produces severe impairments in performance on some but not all memory tasks (Deng et al., 2010). Studies attempting to correlate natural decline of neurogenesis and memory with age have been controversial. In one such study, a sub-population of old (20 months) rats showed cognitive impairment in correlation with the number of adult-produced new neurons (Drapeau et al., 2003). Interestingly, old unimpaired rats performed nearly as well as the young (2 months) rats even though the former had only a fraction of the new neurons in comparison to the young. Other studies failed to demonstrate a relationship between neurogenesis and memory performance (Bizon and Gallagher, 2003; Merrill et al., 2003). Methodological reasons may account for these discrepancies between studies. For example, it would appear that spatial memory tasks may not be optimal for testing the influence of neurogenesis since many studies failed to demonstrate a clear cause-effect relationship in such tasks (Leuner et al., 2006) while others produced varied effects on either short-term or long-term memory (Dupret et al., 2008; Imayoshi et al., 2008; Jessberger et al., 2009). Species differences should also be considered since neurogenesis varies in its rate and physiological significance among species (Snyder et al., 2009a; Johnson et al., 2010)."}

{"project":"0_colil","denotations":[{"id":"20877422-15118105-264424","span":{"begin":290,"end":294},"obj":"15118105"},{"id":"20877422-16371948-264425","span":{"begin":314,"end":318},"obj":"16371948"},{"id":"20877422-14614143-264426","span":{"begin":774,"end":778},"obj":"14614143"},{"id":"20877422-12859354-264427","span":{"begin":1077,"end":1081},"obj":"12859354"},{"id":"20877422-12640670-264428","span":{"begin":1099,"end":1103},"obj":"12640670"},{"id":"20877422-16421862-264429","span":{"begin":1403,"end":1407},"obj":"16421862"},{"id":"20877422-18509506-264430","span":{"begin":1503,"end":1507},"obj":"18509506"},{"id":"20877422-18758458-264431","span":{"begin":1526,"end":1530},"obj":"18758458"},{"id":"20877422-19181621-264432","span":{"begin":1551,"end":1555},"obj":"19181621"},{"id":"20877422-20487030-264434","span":{"begin":1726,"end":1730},"obj":"20487030"}],"text":"The functional role of adult neurogenesis in the hippocampal dentate gyrus remains controversial. Dentate gyrus as a whole is thought to be strongly related to cognitive decline in old age but the exact contribution of neurogenesis vs. other forms of plasticity is uncertain (Small et al., 2004; Burke and Barnes, 2006). There is convincing evidence that experimentally-induced decline in neurogenesis produces severe impairments in performance on some but not all memory tasks (Deng et al., 2010). Studies attempting to correlate natural decline of neurogenesis and memory with age have been controversial. In one such study, a sub-population of old (20 months) rats showed cognitive impairment in correlation with the number of adult-produced new neurons (Drapeau et al., 2003). Interestingly, old unimpaired rats performed nearly as well as the young (2 months) rats even though the former had only a fraction of the new neurons in comparison to the young. Other studies failed to demonstrate a relationship between neurogenesis and memory performance (Bizon and Gallagher, 2003; Merrill et al., 2003). Methodological reasons may account for these discrepancies between studies. For example, it would appear that spatial memory tasks may not be optimal for testing the influence of neurogenesis since many studies failed to demonstrate a clear cause-effect relationship in such tasks (Leuner et al., 2006) while others produced varied effects on either short-term or long-term memory (Dupret et al., 2008; Imayoshi et al., 2008; Jessberger et al., 2009). Species differences should also be considered since neurogenesis varies in its rate and physiological significance among species (Snyder et al., 2009a; Johnson et al., 2010)."}