Biological inquiry: a new course and assessment plan in response to the call to transform undergraduate biology.

We transformed our first-year curriculum in biology with a new course, Biological Inquiry, in which >50% of all incoming, first-year students enroll. The course replaced a traditional, content-driven course that relied on outdated approaches to teaching and learning. We diversified pedagogical practices by adopting guided inquiry in class and in labs, which are devoted to building authentic research skills through open-ended experiments.

Perinatal exposure to polychlorinated biphenyls Aroclor 1016 or 1254 did not alter brain catecholamines nor delayed alternation performance in Long-Evans rats.

Several reports have indicated that polychlorinated biphenyls (PCB) altered development of biogenic amine systems in the brain, impaired behavioral performances, and disrupted maturation of the thyroid axis. The current study examines whether these developmental effects of PCB are correlated. Timed-pregnant Long-Evans rats were gavaged with the PCB mixture Aroclor 1016 (A-1016, 10 mg/kg) from gestation day (GD) 6 to parturition.

Thyroxine replacement attenuates hypothyroxinemia, hearing loss, and motor deficits following developmental exposure to Aroclor 1254 in rats.

The nervous system is dependent upon thyroid hormones for normal development, and we previously reported that developmental Aroclor 1254 (A1254) exposure caused hypothyroxinemia, hearing loss and other behavioral changes in rats. (Goldey et al., 1995a; Herr et al.

Developmental exposure to Aroclor 1254 produces low-frequency alterations in adult rat brainstem auditory evoked responses.

Developmental exposure of Long-Evans rats to 0, 1, 4, or 8 mg/kg/day Aroclor 1254 (A1254) from Gestational Day 6 through Postnatal Day 21 produces an elevated behavioral threshold for a 1-kHz tone. Brainstem auditory evoked responses (BAERs) were assessed in a subset of these animals (about 1 year old) using filtered clicks at 1 (65 and 80 dB SPL), 4 (60 and 80 dB SPL), 16 (40 and 80 dB SPL), and 32 (40 and 80 dB SPL) kHz. Aroclor 1254 decreased BAER amplitudes at 1 and 4 kHz, but not at 16 or 32 kHz.

Developmental exposure to polychlorinated biphenyls (Aroclor 1254) reduces circulating thyroid hormone concentrations and causes hearing deficits in rats.

Developmental hypothyroidism causes growth deficits, motor dysfunction, and hearing disorders in humans and animals. Therefore, environmental toxicants, such as polychlorinated biphenyls (PCBs), may secondarily affect these endpoints via thyrotoxicity. In this study, Long-Evans rats were given Aroclor 1254 (po), at 0, 1, 4, or 8 mg/kg from Gestation Day 6 through Postnatal Day (PND) 21.