Fig. 3. Competition between uptake of AGMn³⁺Tf and Fe³⁺Tf and inhibition of uptake by chlorpromazine and dynasore using confocal microscopy.

Uptake of AGMn³⁺Tf into the cell interior as measured by green emission ocurring within regions of interest drawn just inside the plasma membrane of A. HT22 (hippocampal) neurons and B. STHdhQ7/Q7 (striatal) neurons measured using “Image J” software obtained from NIH. 0.2 μM AGMn³⁺Tf was added at time zero in each of these experiments and excess AGMn³⁺Tf washed away with a flow of fresh medium at time 1 min with the flow of medium continuing for 1 min. Movement of the AGMn³⁺Tf into the neurons was determined by measuring the average emission intensity per unit area using Image J software inside the regions of interest drawn around the inside of the cell membrane as shown in supplementary figure S5. In these experiments, the regions of interest were drawn around the inside of the plasma membrane of each cell within the field of view and the average emission intensity per unit area taken and averaged over all of the cells. Control: 0.2 μM Mn³⁺Tf no other additions (●): 80 μM Fe³⁺Tf (∎) was added and washed away before time zero; 30 μM chlorpromazine (◆) was added 10 min prior to time zero; 80 μM dynasore (▴) was added 10 min prior to zero time. The error bars represent ± 1 standard deviation of three independent measurements. The curves through the data points represent fits to the equation y = m₁ + m₂(1-e^−m3x) with each point weighted by its reliability and the values of m₁, m₂, and m₃ determined by the fit.