May 1, 2019
In the largest study of its kind, involving more than 50,000 subjects in 14 countries, researchers at the Icahn School of Medicine at Mount Sinai and more than 200 collaborating institutions have identified 20 new genetic associations with one of the most prevalent and elusive mental illnesses of... Read More
April 16, 2019
To the Editor:
I was pleased to see our research cited in the article about key lessons about education-technology research for educators ("The Best Ed-Tech Research: 5 Key... Read More
April 9, 2019
To the Editor:
A new analysis by the Education Week Research Center finds "charter high schools … make up an outsized share of the number of public schools persistently graduating less than half of their students" ("... Read More
March 8, 2019
People with Down syndrome are highly protected from most solid tumor cancers, and yet they are highly predisposed to certain blood cancers. Studying people with Down syndrome may lead to new cancer treatments that could benefit everyone.
ACCORDING T... Read More
March 4, 2019
ROCHESTER, Minn. — People who stop breathing during sleep may have higher accumulations of the toxic protein tau, a biological hallmark of Alzheimer's disease... Read More
January 14, 2019
Scientists have located an intriguing link between schizophrenia and the Epstein-Barr virus, a type of herpes virus. Now, they need to determine which way the risk lies.
... Read More
September 12, 2018
In the early 1900s, Edward Thorndike emerged as the educational leader of the day (Lagemann, 1989). As a behaviorist, he asserted that students should gain knowledge in ways (Thorndike, 1906). On the other hand, John Dewey, one of Thorndike's... Read More
August 9, 2018
Purkinje cells are a central part of the human cerebellum, the part of the brain that plays an important role in motor learning, fine motor control of the muscle, equilibrium and posture but also influences emotions, perception, memory and language.
Scientists from the Institute for V... Read More
July 16, 2018
DEEPER LEARNING... Read More
June 14, 2018
You've likely heard the s... Read More
Immediate and long-lasting cognitive consequences of adolescent chronic sleep restriction.
The present study investigated immediate and long-lasting cognitive effects of chronic sleep restriction (CSR) in adolescent rats. After 10 days of CSR produced by gentle handling, both hippocampal-dependent and non-hippocampal-dependent long-term memory abilities were tested using the object location task and the object recognition task, respectively. Testing occurred in adolescence and after a 4-week delay during which rats slept freely and matured to adulthood. Rats exposed to CSR showed impaired memory on the object location task during adolescence that persisted into adulthood. However, there was no effect of CSR on memory for the object recognition task at either time point. These resu...
Timing is everything: Developmental differences in the effect of chronic corticosterone exposure on extinction retention.
Adolescence is noted as a time of “storm and stress.” In this developmental stage both rodents and humans exhibit an impairment in the extinction of learned fear; however, this impairment can be alleviated, at least in rodents, by increasing the amount of extinction training given or by administering the partial NMDA receptor agonist D-Cycloserine. In the present study we explored whether the benefits of these treatments would be reduced by chronic exogenous corticosterone (a commonly studied stress-related hormone). In 2 experiments, adolescent rats were given pairings of a white noise and shock (acquisition) and then given extinction training (white noise presented alone). In Experimen...
Histone deacetylase inhibition differentially attenuates cue-induced reinstatement: An interaction of environment and acH3K9 expression in the dorsal striatum.
Substance use disorder is driven by complex gene-environment interactions. Epigenetic histone regulation is a significant contributor to several behavioral phenotypes of drug abuse. The primary epigenetic mechanisms that drive drug taking and drug seeking are still being investigated, and it is unclear how environmental conditions alter epigenetic histone acetylation to change behaviors geared toward drug reward. This study examined the effects of environmental condition on amphetamine self-administration, and whether drug-taking and drug-seeking behaviors could be influenced through inhibition of an epigenetic regulator, histone deacetylase (HDAC). Male rats reared for 30 days in enriched (...
Neuronal activation in orbitofrontal cortex subregions: Cfos expression following cue-induced reinstatement of cocaine-seeking behavior.
Cocaine-use disorders are characterized by repeated relapse to drug-seeking and drug-taking behavior following periods of abstinence. Former drug users display increased activation of the orbitofrontal cortex (OFC) in response to drug-related cues, and similar phenomena are also observed in rodent models of drug relapse. The lateral, but not medial, OFC functionally contributes to the maintenance of cue-drug associations; however, less is known about the role of the ventral OFC in this process. To examine the pattern of neuronal activation in OFC subregions in response to drug-associated cues, rats were trained to respond on a lever for a cocaine infusion paired with a complex cue (2-hr sess...
Bilateral postsubiculum lesions impair visual and nonvisual homing performance in rats.
Nearly all species rely on visual and nonvisual cues to guide navigation, and which ones they use depend on the environment and task demands. The postsubiculum (PoS) is a crucial brain region for the use of visual cues, but its role in the use of self-movement cues is less clear. We therefore evaluated rats’ navigational performance on a food-carrying task in light and in darkness in rats that had bilateral neurotoxic lesions of the PoS. Animals were trained postoperatively to exit a refuge and search for a food pellet, and carry it back to the refuge for consumption. In both light and darkness, control and PoS-lesioned rats made circuitous outward journeys as they searched for food. Howev...
Operant conditioning prevents cell death in the adult rat dentate gyrus.
Thousands of new neurons are produced each day in the dentate gyrus of the adult mammalian hippocampus. However, the majority of those cells die within weeks of their birth. The most effective way to prevent this cell death is through effortful and successful learning. Myriad studies have revealed that classical conditioning and spatial learning can prevent this cell death. However, little research has examined whether acquisition of an operant conditioning task with an appetitive reward also increases the number of surviving cells. Therefore, the current study was conducted to determine whether conditioning with an operant procedure would prevent the death of adult-born hippocampal cells. A...
Gonadal hormone fluctuations do not affect the expression or extinction of fear-potentiated startle in female rats.
Prior studies suggest that levels of ovarian hormones may affect learning and memory in rats, including studies of fear conditioning and extinction. We previously showed that female rats show reduced retention of extinction compared to males when measuring fear-potentiated startle, but not when measuring freezing behavior. One commonly reported observation in studies of freezing behavior is that rats with increased levels of estradiol during extinction learning show better retention of extinction than rats given extinction training when levels of estradiol are low. Here, we tested the hypothesis that fear extinction retention in a fear-potentiated startle paradigm in females is influenced by...
Development of an “object category recognition” task for mice: Involvement of muscarinic acetylcholine receptors.
Recent research suggests that rats are capable of object categorization-like processes. To study whether mice possess similar abilities, we developed a spontaneous one-trial object category recognition (OCR) task. Based on the spontaneous object recognition paradigm, mice discriminated between two otherwise equally novel objects, one from a novel category and one from a studied category. During the sample phase, mice were exposed to two different exemplars from the same category. After a retention delay, they explored a third (i.e., novel) object from that sampled category and an object from a novel category in a choice phase. Mice preferentially explored the novel category object, taken as ...
Aged rats with intact memory show distinctive recruitment in cortical regions relative to young adults in a cue mismatch task.
Similar to elderly humans, aged Long–Evans rats exhibit individual differences in performance on tasks that critically depend on the medial temporal lobe memory system. Although reduced memory performance is common, close to half of aged rats in this outbred rodent population perform within the range of young subjects, exhibiting a stable behavioral phenotype that may signal a resilience to memory decline. Increasing evidence from research on aging in the Long–Evans study population supports the existence of adaptive neural change rather than avoidance of detrimental effects of aging on the brain, indicating a malleability of brain function over the life span that may preserve optimal fu...