To test dopamine transmission across adolescent development, dopamine release was evoked by MFB or PPT stimulation and measured with FSCV during non-survival surgeries in females and males during early adolescence (PND 30–35), late adolescence (PND 50–55) or adulthood (PND 120–125). Female adult rats from control and gelatin decision-making behavioral groups were also tested this way.
Rats were anesthetized with a 1.5 g/kg urethane (i.p.) and head-fixed in a Kopf stereotaxic instrument. The skull was exposed and burr holes were drilled targeting the NAcc (relative to bregma: 1.3 mm anterior and 1.3 mm lateral, MFB (relative to bregma: 4.6 mm posterior and 0.8 mm lateral), and PPT (relative to bregma: 8.0 mm posterior and 2.0 mm lateral). Another burr hole was drilled on the contralateral side for placement of the reference electrode (Ag/AgCl). A carbon-fiber microelectrode was centered above the NAcc burr hole and lowered 6.8–7.2 mm ventral from the top of the brain.
On completion of the experiment, current was passed through the voltammetry electrode to produce a lesion to aid histological identification of the recording location. Animals were then sacrificed using phenytoin/pentobarbital (Bethanasia) and their brains were harvested for histological analysis of the recording and stimulating electrode placement. On analysis of these data using one-way analysis of variance (ANOVA), there were no significant differences in electrode placement between experimental groups. Specifically, no differences were observed (p < 0.05) between working electrode placement in the NAcc (dorsal/ventral: F(1,61) group = 0.522; medial/lateral: F(1,60) group = 0.9984; anterior/posterior: F(1,61) group = 1.275), stimulating electrode placement MFB (dorsal/ventral: F(1,37) group = 0.7424; medial/lateral: F(1,37) group = 0.7336; anterior/posterior: F(1,37) group = 0.8156) or stimulating electrode PPT (dorsal/ventral: F1,44) group = 0.7081; medial/lateral: F(1,44) group = 1.315; anterior/posterior: F(1,44) group = 0.4166) between experimental groups.
Rats were anesthetized with a 1.5 g/kg urethane (i.p.) and head-fixed in a Kopf stereotaxic instrument. The skull was exposed and burr holes were drilled targeting the NAcc (relative to bregma: 1.3 mm anterior and 1.3 mm lateral, MFB (relative to bregma: 4.6 mm posterior and 0.8 mm lateral), and PPT (relative to bregma: 8.0 mm posterior and 2.0 mm lateral). Another burr hole was drilled on the contralateral side for placement of the reference electrode (Ag/AgCl). A carbon-fiber microelectrode was centered above the NAcc burr hole and lowered 6.8–7.2 mm ventral from the top of the brain.
On completion of the experiment, current was passed through the voltammetry electrode to produce a lesion to aid histological identification of the recording location. Animals were then sacrificed using phenytoin/pentobarbital (Bethanasia) and their brains were harvested for histological analysis of the recording and stimulating electrode placement. On analysis of these data using one-way analysis of variance (ANOVA), there were no significant differences in electrode placement between experimental groups. Specifically, no differences were observed (p < 0.05) between working electrode placement in the NAcc (dorsal/ventral: F(1,61) group = 0.522; medial/lateral: F(1,60) group = 0.9984; anterior/posterior: F(1,61) group = 1.275), stimulating electrode placement MFB (dorsal/ventral: F(1,37) group = 0.7424; medial/lateral: F(1,37) group = 0.7336; anterior/posterior: F(1,37) group = 0.8156) or stimulating electrode PPT (dorsal/ventral: F1,44) group = 0.7081; medial/lateral: F(1,44) group = 1.315; anterior/posterior: F(1,44) group = 0.4166) between experimental groups.
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