Chronic treatment with cocaine also increased the level of transcripts that include the Kal7-specific 3'-terminal exon (Figure 8). Inclusion of this 3'-terminal exon results in the production of transcripts encoding Kal7 or ΔKal7 and precludes the production of Kal8, Kal9 or Kal12. Since chronic cocaine treatment had no effect on the level of full-length Kalirin transcripts (Figure 8B), an increase in the splicing events that include the Kal7-specific 3'-terminal exon would be associated with diminished usage of other 3'-terminal exons. While usage of the Kal8- and Kal12-specific exons was unaltered, usage of the Kal9-specific 3'-terminal exon declined slightly.
