Increased Pass Rates in Introductory Biology: Benefits and Potential Costs of Implementing a Mathematics Prerequisite in a Community College Setting.

We explored the impacts of a mathematics prerequisite on student success in Introductory Biology, focusing on students historically underserved in science, technology, engineering, and mathematics (STEM). Specifically, we studied Introductory Biology student outcomes 5 years before and 6 years after adding the prerequisite. Students who had not previously passed Intermediate Algebra had a 54.91% chance of passing Introductory Biology, compared with a ​​69.25% chance for students who had passed this math course. Furthermore, we found a disproportionate benefit of passing the math course for Pell Grant recipients. When considering pre- versus post-prerequisite terms of Introductory Biology, we found pass rates were significantly higher after the mathematics prerequisite was required, but grades were not. After the mathematics prerequisite, enrollments in Introductory Biology temporarily decreased in comparison to a similar chemistry course and the college's overall enrollments, a potential cost to students. Pell Grant recipients and women took Introductory Biology at the same rate as before, and contrary to our hypothesis, we saw the proportion of persons excluded due to ethnicity or race (PEER) students enrolled in Introductory Biology was higher after the implementation. This study provides a model for assessing prerequisites in a local context and contributes evidence that mathematical prerequisites can benefit students.

The 5-HT1A receptor modulates the effects of cocaine on extracellular serotonin and dopamine levels in the nucleus accumbens.

The regulation of extracellular levels of serotonin (5-HT) and dopamine in response to cocaine by 5-HT1A receptors was examined using in vivo microdialysis and the 5-HT1A receptor antagonist 4-(2'-methoxy-)-phenyl-1-[2'-(N-2''-pyridinyl)-p-fluorobenzamido-]ethyl-piperazine (p-MPPF). Pretreatment with p-MPPF significantly augmented the increase in extracellular levels of both 5-HT and dopamine in the nucleus accumbens produced by systemic administration of cocaine. Levels of 5-HT or dopamine were unaffected by p-MPPF given alone. Extracellular levels of 5-HT and dopamine were increased dramatically by cocaine infused locally into the nucleus accumbens. Systemic injection of cocaine given during the cocaine infusion reduced 5-HT and dopamine levels, presumably by activating inhibitory 5-HT and dopamine autoreceptors outside of the locus of infusion. The reduction of 5-HT and dopamine levels by systemic cocaine during accumbal infusion was blocked by pretreatment with the 5-HT1A receptor antagonist p-MPPF. Taken together, these findings suggest that the 5-HT1A autoreceptor acts to modulate the effects of cocaine on both 5-HT and dopamine levels in the nucleus accumbens.