Glutamate and AMPA enhanced internalization of AMPARs.
(A) Detection of internalization of AMPARs. In untreated
cultures, clear staining of GluR1 is seen on the surface, along the
edge of the cell body and dendrites (red), whereas the staining inside
the cell body is more homogeneous and weak (green). This distribution
is altered by incubation with glutamate: staining becomes weaker on the
surface, but stronger inside the cell body that occupies the
perinuclear region. (Scale bar: 10 μm.) (B)
Quantification of internalization of AMPARs. Ratio of the fluorescence
intensity inside the cell body vs. on the surface was calculated and
used as an index for internalization. The results were normalized to
the control group. In the groups treated with glutamate, a higher ratio
is obtained (for control, n = 19 cells from 6
experiments; for glutamate, n = 16 cells from 6
experiments). (C) A similar change is observed when AMPA
is applied (for control, n = 18 cells from 5
experiments; for AMPA, n = 19 cells from 5
experiments).