Journal of undergraduate neuroscience education : JUNE : a publication of FUN, Faculty for Undergraduate Neuroscience, 2014
The University of New England's Center for Excellence in the Neurosciences has developed a su... more The University of New England's Center for Excellence in the Neurosciences has developed a successful and growing K-12 outreach program that incorporates undergraduate and graduate/professional students. The program has several goals, including raising awareness about fundamental issues in neuroscience, supplementing science education in area schools and enhancing undergraduate and graduate/professional students' academic knowledge and skill set. The outreach curriculum is centered on core neuroscience themes including: Brain Safety, Neuroanatomy, Drugs of Abuse and Addiction, Neurological and Psychiatric Disorders, and Cognition and Brain Function. For each theme, lesson plans were developed based upon interactive, small-group activities. Additionally, we've organized our themes in a "Grow-up, Grow-out" approach. Grow-up refers to returning to a common theme, increasing in complexity as we revisit students from early elementary through high school. Grow-out re...
Although contextual fear conditioning emerges later in development than explicit-cue fear conditi... more Although contextual fear conditioning emerges later in development than explicit-cue fear conditioning, little is known about the stimulus parameters and biological substrates required at early ages. The authors adapted methods for investigating hippocampus function in adult rodents to identify determinants of contextual fear conditioning in developing rats. Experiment 1 examined the duration of exposure required by weanling rats at postnatal day (PND) 23 to demonstrate contextual fear conditioning. This experiment demonstrated that 30 s of context exposure is sufficient to support conditioning. Furthermore, preexposure enhanced conditioning to an immediate footshock, the context preexposure facilitation effect (CPFE), but had no effect on contextual conditioning to a delayed shock. Experiment 2 demonstrated that N-methyl-D-aspartate (NMDA) receptor inactivation during preexposure impairs contextual learning at PND 23. Thus, the conjuctive representations underlying the CPFE are NMDA-dependent as early as PND23 in the rat.
Emotional events often lead to particularly strong memory formation. Corticosterone, the final pr... more Emotional events often lead to particularly strong memory formation. Corticosterone, the final product of hypothalamic-pituitary-adrenal (HPA)-axis activation, has been suggested to play a critical role in this effect. Although a great deal of work has implicated the amygdala as a necessary structure for the effects of corticosterone, other studies have suggested a critical role for the hippocampus in determining the involvement of corticosterone. The current experiments examined this question by disrupting corticosterone synthesis with administration of metyrapone (25 or 100 mg/kg) prior to training in either dorsal hippocampus-independent delay fear conditioning or dorsal hippocampus-dependent trace fear conditioning. Metyrapone administration 2 hrs prior to training significantly attenuated corticosterone secretion during training, but these effects were transient as corticosterone levels were similar to control subjects following the test session. As hypothesized, only trace fear conditioning was impaired. This suggests that only fear conditioning tasks that are dependent on the dorsal hippocampus require HPA-axis activation in order to be learned.
Journal of undergraduate neuroscience education : JUNE : a publication of FUN, Faculty for Undergraduate Neuroscience, 2014
The University of New England's Center for Excellence in the Neurosciences has developed a su... more The University of New England's Center for Excellence in the Neurosciences has developed a successful and growing K-12 outreach program that incorporates undergraduate and graduate/professional students. The program has several goals, including raising awareness about fundamental issues in neuroscience, supplementing science education in area schools and enhancing undergraduate and graduate/professional students' academic knowledge and skill set. The outreach curriculum is centered on core neuroscience themes including: Brain Safety, Neuroanatomy, Drugs of Abuse and Addiction, Neurological and Psychiatric Disorders, and Cognition and Brain Function. For each theme, lesson plans were developed based upon interactive, small-group activities. Additionally, we've organized our themes in a "Grow-up, Grow-out" approach. Grow-up refers to returning to a common theme, increasing in complexity as we revisit students from early elementary through high school. Grow-out re...
Although contextual fear conditioning emerges later in development than explicit-cue fear conditi... more Although contextual fear conditioning emerges later in development than explicit-cue fear conditioning, little is known about the stimulus parameters and biological substrates required at early ages. The authors adapted methods for investigating hippocampus function in adult rodents to identify determinants of contextual fear conditioning in developing rats. Experiment 1 examined the duration of exposure required by weanling rats at postnatal day (PND) 23 to demonstrate contextual fear conditioning. This experiment demonstrated that 30 s of context exposure is sufficient to support conditioning. Furthermore, preexposure enhanced conditioning to an immediate footshock, the context preexposure facilitation effect (CPFE), but had no effect on contextual conditioning to a delayed shock. Experiment 2 demonstrated that N-methyl-D-aspartate (NMDA) receptor inactivation during preexposure impairs contextual learning at PND 23. Thus, the conjuctive representations underlying the CPFE are NMDA-dependent as early as PND23 in the rat.
Emotional events often lead to particularly strong memory formation. Corticosterone, the final pr... more Emotional events often lead to particularly strong memory formation. Corticosterone, the final product of hypothalamic-pituitary-adrenal (HPA)-axis activation, has been suggested to play a critical role in this effect. Although a great deal of work has implicated the amygdala as a necessary structure for the effects of corticosterone, other studies have suggested a critical role for the hippocampus in determining the involvement of corticosterone. The current experiments examined this question by disrupting corticosterone synthesis with administration of metyrapone (25 or 100 mg/kg) prior to training in either dorsal hippocampus-independent delay fear conditioning or dorsal hippocampus-dependent trace fear conditioning. Metyrapone administration 2 hrs prior to training significantly attenuated corticosterone secretion during training, but these effects were transient as corticosterone levels were similar to control subjects following the test session. As hypothesized, only trace fear conditioning was impaired. This suggests that only fear conditioning tasks that are dependent on the dorsal hippocampus require HPA-axis activation in order to be learned.
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