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Flipped instruction using online enrichment is a popular way to enhance active learning in the laboratory setting. Graduate student teaching assistants at University of California, Irvine flipped an upper division undergraduate neurobiology and behavior lab using the new online software platform “Rocketmix.” The following research study compares the impact of pre-lab online instruction (front flipping) and post-lab online instruction (back flipping) on student exam performance. We describe a novel method for unbiased categorization of exam questions by degree of difficulty. Multi-choice instruction encourages students to consider all distractors and discourages verbal cues and process of elimination techniques. Eighteen identical questions were evenly distributed across exam versions with multiple choice instruction (single answer) or a more challenging multi-choice instruction (more than one answer). Student performance on multiple choice questions were used to categorize the degree of difficulty of questions that were presented in multi-choice format. Our findings reveal that pre-lab instruction resulted in better student performance compared with post-lab instruction on questions of moderate difficulty. This effect was significant for both male and female students. Student survey data on the flipped lab format is provided, indicating that students appreciated the online instructional modules, finding them both informative and useful during lab exercises and exams.

Stress can exert long-lasting changes on the brain that contribute to vulnerability to mental illness, yet mechanisms underlying this long-term vulnerability are not well understood. We hypothesized that stress may alter the production of oligodendrocytes in the adult brain, providing a cellular and structural basis for stress-related disorders. We found that immobilization stress decreased neurogenesis and increased oligodendrogenesis in the dentate gyrus (DG) of the adult rat hippocampus, and that injections of the rat glucocorticoid stress hormone corticosterone (cort) were sufficient to replicate this effect. The DG contains a unique population of multipotent neural stem cells (NSCs) that give rise to adult newborn neurons, but oligodendrogenic potential has not been demonstrated in vivo. We used a nestin-CreER/YFP transgenic mouse line for lineage tracing and found that cort induces oligodendrogenesis from nestin-expressing NSCs in vivo. Using hippocampal NSCs cultured in vitro, we further showed that exposure to cort induced a pro-oligodendrogenic transcriptional program and resulted in an increase in oligodendrogenesis and decrease in neurogenesis, which was prevented by genetic blockade of glucocorticoid receptor (GR). Together, these results suggest a novel model in which stress may alter hippocampal function by promoting oligodendrogenesis, thereby altering the cellular composition and white matter structure.

Active teaching is increasingly accepted as a better option for higher education STEM courses than traditional lecture-based instruction. However, concerns remain regarding student preferences and the impact of increased course structure on teaching evaluations. Undergraduates in a non-majors neuropharmacology course were enrolled in an enriched blended course format, providing online case-based learning opportunities in a large lecture hall setting. Students working in small assigned groups solved weekly case studies developed to teach basic neuropharmacology concepts. All case study assignments were peer reviewed and content was further reinforced with a weekly online quiz. A comparison of scores on equivalent midterm and final exam questions revealed that students enrolled in the High-Structure course scored better than students from the previous year that took a more traditional Low-Structure lecture-based course. Student performance increased significantly for exam questions that required Bloom’s level understanding. When surveyed, students in the High-Structure course reported some regret for the lack of traditional lecture and revealed some disapproval towards the extra work required for active teaching and peer review. Yet, we saw no change in quantitative instructor evaluation between sections, challenging the idea that student resistance towards increased work lowers course evaluation scores. Future instructors using active learning strategies may benefit from revealing to students the value of increased course structure on performance outcomes compared with traditional lecture courses.

Glucocorticoids, the adrenal steroids released during stress, compromise the ability of neurons to survive neurological injury. In contrast, estrogen protects neurons against such injuries. We designed three genetic interventions to manipulate the actions of glucocorticoids, which reduced their deleterious effects in both in vitro and in vivo rat models. The most effective of these interventions created a chimeric receptor combining the ligand-binding domain of the glucocorticoid receptor and the DNA-binding domain of the estrogen receptor. Expression of this chimeric receptor reduced hippocampal lesion size after neurological damage by 63% and reversed the outcome of the stress response by rendering glucocorticoids protective rather than destructive. Our findings elucidate three principal steps in the neuronal stress-response pathway, all of which are amenable to therapeutic intervention.

Agonist-induced decrease in core body temperature has commonly been used as a measure of serotonin1A (5-HT(1A)) receptor sensitivity in mood disorder. The thermoregulatory basis for 5-HT(1A) receptor agonist-induced temperature responses in humans and rats remains unclear. Therefore, the influence of ambient temperature on 5-HT(1A) receptor-mediated decreases in core body temperature were measured in rat lines bred for high (HDS) or low (LDS) sensitivity to the selective 5-HT(1A) receptor agonist 8-hydroxy-dipropylaminotetralin (8-OH-DPAT). HDS and LDS rats were injected with either saline, 0.25 or 0.50 mg/kg 8-OH-DPAT at ambient temperatures of 10.5, 24, 30, or 37.5 degrees C, and core temperature was measured by radiotelemetry. For both lines, the thermic response to acute 8-OH-DPAT was greatest at 10.5 degrees C and decreased in magnitude as ambient temperature increased to 30 degrees C, consistent with hypothermia. HDS rats displayed a greater hypothermic response than LDS rats at 10.5, 24, and 30 degrees C. At 37.5 degrees C, LDS rats showed a lethal elevation of temperature in response to 0.50 mg/kg 8-OH-DPAT. All thermic responses to 8-OH-DPAT, including the lethality, were effectively blocked by pretreatment with the 5-HT(1A) receptor antagonist WAY100635, suggesting line differences in thermoregulatory circuits that are influenced by 5-HT(1A) receptor activation. Following repeated injection of 8-OH-DPAT, the magnitude of the hypothermic response decreased in both lines at 10.5 degrees C, but increased in HDS rats treated with 0.50 mg/kg 8-OH-DPAT at 30 and 37.5 degrees C. This pattern was reversed in HDS rats following 8-OH-DPAT challenge at 24 degrees C, suggesting that a compensatory thermoregulatory response accounts for changes in the hypothermic response to chronic 8-OH-DPAT.

Hippocampal function is essential for the acquisition, consolidation, and retrieval of spatial memory. High circulating levels of glucocorticoids (GCs), the adrenal steroid hormones secreted during stress, have been shown to impair both acquisition and retrieval and can either impair or enhance consolidation, depending on experimental conditions. In contrast, estrogen can enhance spatial memory performance and can block the deleterious effects of GCs on such performance. We therefore constructed a chimeric gene (“ER/GR”) containing the hormone-binding domain of the GC receptor and the DNA binding domain of the estrogen receptor; as a result, ER/GR transduces deleterious GC signals into beneficial estrogenic ones. We show here that acute immobilization stress, before acquisition and retrieval phases, increases latencies for male rats in a hidden platform version of the Morris water maze. This impairment is blocked by hippocampal expression of the ER/GR transgene. ER/GR expression also blocks decreases in platform crossings caused by acute stress, either after acquisition or before retrieval. Three days of stress before acquisition produces an estrogen-like enhancement of performance in ER/GR-treated rats. Moreover, ER/GR blocks the suppressive effects of GCs on expression of brain-derived neurotrophic factor (BDNF), a growth factor central to hippocampal-dependent cognition and plasticity, instead producing an estrogenic increase in BDNF expression. Thus, ER/GR expression enhances spatial memory performance and blocks the impairing effects of GCs on such performance.