Czupryn Artur, Skangiel-Kramska Jolanta
Department of Molecular and Cellular Neurobiology, The Nencki Institute of Experimental Biology, 3 Pasteur Street, 02-093 Warsaw, Poland.
Brain Res Bull. 2003 Aug 30;61(4):385-91. doi: 10.1016/s0361-9230(03)00140-0.
It has been previously demonstrated that in the mouse barrel cortex, synaptic zinc is regulated by sensory experience. In adult mice, cutting selected vibrissae produced a rapid but transient elevation of synaptic zinc in the corresponding barrels several hours later, whereas in 8 day-old animals this procedure did not affect synaptic zinc. In the present study, we wished to determine the postnatal age at which zinc-containing terminals gain the ability to respond rapidly to a restriction of sensory input. We therefore examined the effects of 1-day sensory deprivation starting at different postnatal ages. For this purpose we unilaterally trimmed all rows of vibrissae, except for row C, and we then visualized synaptic zinc in the barrel cortex 24h later. Up to postnatal day 15 such procedure had no effect on the level of synaptic zinc. However, beginning at postnatal day 16, 1-day sensory deprivation produced an increase in synaptic zinc within hollows of deprived rows of barrels as compared to non-deprived rows. These results show that during development there is a specific time-point after which zinc-containing circuits may respond rapidly to altered sensory inputs. A comparison of these findings with previous results obtained after chronic sensory deprivation suggests that a specific time window exists in development for persistent alterations in zinc-containing circuits.
先前的研究表明，在小鼠桶状皮层中，突触锌受感觉经验调控。在成年小鼠中，剪除特定触须会在数小时后使相应桶状区的突触锌迅速但短暂地升高，而在8日龄动物中，此操作不会影响突触锌。在本研究中，我们希望确定含锌终末获得对感觉输入受限快速做出反应能力的出生后年龄。因此，我们研究了从不同出生后年龄开始的1天感觉剥夺的影响。为此，我们单侧修剪除C排外的所有触须排，然后在24小时后观察桶状皮层中的突触锌。直至出生后第15天，此操作对突触锌水平无影响。然而，从出生后第16天开始，与未剥夺的排相比，1天感觉剥夺使剥夺排桶状区空洞内的突触锌增加。这些结果表明，在发育过程中存在一个特定的时间点，在此之后含锌回路可能对改变的感觉输入快速做出反应。将这些发现与先前慢性感觉剥夺后获得的结果进行比较表明，在发育过程中存在一个特定的时间窗口，用于含锌回路的持续改变。
