Binns KE; Salt TE; (1998) Experience-dependent changes in the importance of N-methyl-D- aspartate (NMDA) receptors for visual transmission in superior colliculus. Developmental Brain Research, 110: 241-248
The excitatory amino acid transmitter glutamate mediates visual activity in the superficial grey
layer (SGS) of superior colliculus. At eye opening N-methyl-D-aspartate receptors (NMDA-rs)
convey Little of the visual response, but with age their role in visual transmission increases to a
peak at P21, then falls to the lower adult level. Visual deprivation which begins before eye
opening causes NMDA-rs to assume a greater importance for visual transmission in SGS. Here
we explore the possibility that these experience- dependent changes in the role of NMDA-rs in
the SGS are limited by age. We find that the effects of visual deprivation on NMDA-r mediated
visual activity are recoverable even after extensive dark rearing. Also, a short episode of visual
experience is sufficient to allow the normal situation to be established and subsequent dark
rearing is ineffective. Four-day periods of visual experience beginning at P14 or P25 have the
same effect. Given that NMDA-rs take little part in visual transmission prior to P18, these data
prompt a reconsideration of the role of NMDA-r mediated sensory transmission in the
mechanisms by which early environmental experience influences the development of the visual
system.
![]() |
![]() |
![]() |
![]() |