Psychophysical studies suggest that lateral extrastriate visual cortical areas in cats may mediate the sparing of vision largely by network reorganization following lesions of early visual cortical areas. To date, how...Psychophysical studies suggest that lateral extrastriate visual cortical areas in cats may mediate the sparing of vision largely by network reorganization following lesions of early visual cortical areas. To date, however, there is little direct physiological evidence to support this hypothesis. Using in vivo single-anit recording techniques, we examined the response of neurons in areas 19, 21, and 20 to different types of visual stimulation in cats with or without acute bilateral lesions in areas 17 and 18. Our results showed that, relative to the controls, acute lesions inactivated the response of 99.3% of neurons to moving gratings and 93% of neurons to flickering square stimuli＇in areas 19, 21, and 20. These results indicated that acute lesions of primary visual areas in adult eats may impair most visual abilities. Sparing of vision in cats with neonatal lesions in early visual cortical areas may result largely from a postoperative reorganization of visual pathways from subcortical nucleus to extrastriate visual cortical areas.展开更多
Two new taraxastane-type triterpenes. 3 beta. 21 beta -dihydroxyl-20(30)-en-taraxastane 1 and 3 beta. 30-dihydroxy-20(21)-en-taraxastane 2. were isolated from Saussurea petrovii. Their structures were elucidated by sp...Two new taraxastane-type triterpenes. 3 beta. 21 beta -dihydroxyl-20(30)-en-taraxastane 1 and 3 beta. 30-dihydroxy-20(21)-en-taraxastane 2. were isolated from Saussurea petrovii. Their structures were elucidated by spectral methods (EIMS. IR. 1D and 2DNMR).展开更多
基金National Natural Science Foundation of China (31171082)Natural Science Foundation of Anhui Province (070413138)Key Research Foundation of Anhui Province Education Department (KJ2009A167)
文摘Psychophysical studies suggest that lateral extrastriate visual cortical areas in cats may mediate the sparing of vision largely by network reorganization following lesions of early visual cortical areas. To date, however, there is little direct physiological evidence to support this hypothesis. Using in vivo single-anit recording techniques, we examined the response of neurons in areas 19, 21, and 20 to different types of visual stimulation in cats with or without acute bilateral lesions in areas 17 and 18. Our results showed that, relative to the controls, acute lesions inactivated the response of 99.3% of neurons to moving gratings and 93% of neurons to flickering square stimuli＇in areas 19, 21, and 20. These results indicated that acute lesions of primary visual areas in adult eats may impair most visual abilities. Sparing of vision in cats with neonatal lesions in early visual cortical areas may result largely from a postoperative reorganization of visual pathways from subcortical nucleus to extrastriate visual cortical areas.
基金the Department of Science and Technology of China for financial support (Grant No. G1998051113).
文摘Two new taraxastane-type triterpenes. 3 beta. 21 beta -dihydroxyl-20(30)-en-taraxastane 1 and 3 beta. 30-dihydroxy-20(21)-en-taraxastane 2. were isolated from Saussurea petrovii. Their structures were elucidated by spectral methods (EIMS. IR. 1D and 2DNMR).
