Real-Time Measurements of Phasic Changes in Extracellular Dopamine Concentration in Freely Moving Rats by Fast-Scan Cyclic Voltammetry - Drugs of Abuse: Neurological Reviews and Protocols - page 448

Fig. 3. Extracellular dopamine transient in the nucleus accumbens core of a male rat
at investigation of another male. The voltammetric trace at the peak oxidation potential
for dopamine is shown at the top , and the arrows indicate the time points of the cyclic
voltammograms and video stills. Each point represents current from one voltammetric
scan, collected every 100 ms. The test rat (on the right in each video frame with
a tether) approaches the target rat ( left panel ) and at the point he makes contact
( middle panel ), there is a rapid but transient rise in the voltammetric signal. On further
interaction ( right panel ), there is no further change in the voltammetric signal. The
background-subtracted voltammograms indicate that the rise in the voltammetric signal
was due to an increase in dopamine concentration ( middle ), and that there was no
change in dopamine concentration either 2 s before ( left ; before initial contact)
or 2 s after ( right ; during further interaction) the transient. The concentration of
dopamine was estimated from in vitro post-experimental calibration of the carbon fi ber
microelectrode, and is shown in the scale bar.
tion of receptive females. Preliminary data suggest that similar responses occur
with presentation of males ( Fig. 3 ), suggesting a nonsexual role for this signal.
The transients tended to occur at the initial interaction with the target rat and
are followed by intense sniffi ng and often locomotion. These results and those