Dopaminergic Suppression of Synaptic Transmission in the Lateral Entorhinal Cortex
Figure 2
High concentrations of dopamine increase
paired-pulse facilitation. (a) Pairs of stimulation pulses with a 30 millisecond interpulse interval
were delivered before and after 5-minute bath application of 50 M
dopamine. Averaged traces at left show
responses recorded before (ACSF) and after (DA) dopamine from a representative
cell. Note the suppression of the
response to the first pulse and the large facilitation of the second response
following dopamine (dotted line). Traces
at right have been scaled to the amplitude of the first response in normal ACSF
to aid comparison. Group data are shown
on the right. (b) Paired-pulse
facilitation was also enhanced by 10 M dopamine. (c) In contrast, the low concentration of 1 M
dopamine does not affect paired-pulse ratio.
