Table 1.

d-amphetamine activation of ERK1/2 in striatal neurons in wild type, Drd1a- and DARPP-32 KO mice.

STRIATAL REGION	Wild type	drd1a-KO	p value ** <0.01	Wild type	DARPP32-KO	p value ** <0.01<n.s.
dorsal lateral	5.2	6.0	0.268	4.7	5.5	n.s.0.268
dorsal medial	19.7	21.3	0.322	18.7	21.0	n.s.0.294
accumbens	55.8	19.3	**0.0011	47.3	18.5	**0.0011

Counts of neurons showing phospho-ERK1/2 in different regions of the striatum and nucleus accumbens from animals in treatment groups described in this study. Treatment groups with d-amphetamine (10 mg/kg, ip) included wild type and drd1a- and DARPP-32-knockout animals. Cell counts are the average from 6 animals per treatment group (n=6) measured in a 100 um² area in each region. Wilcoxon ranks sums test show that there is only a significant reduction (** p value <0.01) in amphetamine-induction of phospho-ERK1/2 neurons in the nucleus accumbens in both drd1a-KO and DARPP-32 KO animals compared to wild type.