کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4340353 1295790 2008 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Aging affects contrast response functions and adaptation of middle temporal visual area neurons in rhesus monkeys
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی علوم اعصاب (عمومی)
پیش نمایش صفحه اول مقاله
Aging affects contrast response functions and adaptation of middle temporal visual area neurons in rhesus monkeys
چکیده انگلیسی
In the present study we studied the effects of aging on the coding of contrast in area V1 (primary visual cortex) and MT (middle temporal visual area) of the macaque monkey using single-neuron in vivo electrophysiology. Our results show that both MT and V1 neurons in old monkeys are less sensitive to contrast than those in young monkeys. Generally, contrast sensitivity is affected by aging more severely in MT cells than in V1 cells. Specifically, MT cells were affected more severely than motion direction selective V1 cells. Particularly, we found that MT neurons in old monkeys exhibited enhanced maximum visual responses, higher levels of spontaneous activity and decreased signal-to-noise ratios. In addition, we also found age-related changes in neuronal adaptation to visual motion in MT. Compared with young animals, the contrast gain of MT neurons in old monkeys is less affected, but the response gain by adaptation of MT neurons is more affected. Our results suggest that there may be an anomalous visual processing in both the magnocellular and parvocellular pathways. The neural changes described here are consistent with an age-related degeneration of intracortical inhibition and could underlie some deficits in visual function during normal aging.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Neuroscience - Volume 156, Issue 3, 15 October 2008, Pages 748-757
نویسندگان
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