Feds Invest $10 Million Into Research for Severe Learning Disabilities
September 6, 2013

Developing strategies to help elementary students with the most severe learning disabilities is the focus of a new research project to be based at Vanderbilt University in Nashville, Tenn.
The National Center for Special Education Research awarded a 5-y...
Read More
Page 7 of 7
1 5 6 7
A role for neurogenesis in probabilistic reward learning.
Rewards are often unreliable and optimal choice requires behavioral flexibility and learning about the probabilistic nature of uncertain rewards. Probabilistic learning occurs over multiple trials, often without conscious knowledge, and is traditionally associated with striatal function. While the hippocampus is classically recognized for its role in memory for individual experiences, recent work indicates that it is also involved in probabilistic forms of learning but little is known about the features that support such learning. We hypothesized that adult neurogenesis may be involved, because adult-born neurons contribute to both learning and reward-related behaviors. To test this, we used...
Read Article
Partial integration of the components of value in anterior cingulate cortex.
Evaluation often involves integrating multiple determinants of value, such as the different possible outcomes in risky choice. A brain region can be placed either before or after a presumed evaluation stage by measuring how responses of its neurons depend on multiple determinants of value. A brain region could also, in principle, show partial integration, which would indicate that it occupies a middle position between (preevaluative) nonintegration and (postevaluative) full integration. Existing mathematical techniques cannot distinguish full from partial integration and therefore risk misidentifying regional function. Here we use a new Bayesian regression-based approach to analyze responses...
Read Article
Chemogenetic inhibition of dopaminergic projections to the nucleus accumbens has sexually dimorphic effects in the rat gambling task.
Women and men can differ in their propensity to take risks and develop impulse control and addiction disorders. Sexual dimorphisms in behavioral control by the mesolimbic dopaminergic reward system may underlie these phenomena, given its sensitivity to gonadal hormones. However, this is hard to test experimentally using humans. Using the rat gambling task (rGT), we investigated what impact acute inhibition of accumbal dopamine had on decision-making and impulsivity in animals of both sexes. We expressed an inhibitory designer receptor exclusively activated by designer drugs (hM4D[Gi]) in the accumbal dopaminergic efferents of female and male transgenic (Tg) rats, engineered to selectively ex...
Read Article
Acute NMDA receptor antagonism impairs working memory performance but not attention in rats—Implications for the NMDAr hypofunction theory of schizophrenia.
Cognitive deficits in schizophrenia, which include impairments in working memory and attention, represent some of the most disabling symptoms of this complex psychiatric condition, and lack effective treatments. NMDA receptor (NMDAr) hypofunction is a strong candidate mechanism underlying schizophrenia pathophysiology, and has been modeled preclinically using acute administration of NMDAr antagonists to rodents to investigate biological mechanisms underpinning cognitive dysfunction. However, whether and how NMDAr hypofunction specifically influences all affected cognitive domains is unclear. Here we studied the effects of the NMDAr antagonist MK-801 (dizocilpine) on tasks of attention and wo...
Read Article
Context-dependent odor learning requires the anterior olfactory nucleus.
Learning to associate the context in which a stimulus occurs is an important aspect of animal learning. We propose that the association of an olfactory stimulus with its multisensory context is mediated by projections from ventral hippocampus (vHC) networks to the anterior olfactory nucleus (AON). Using a contextually cued olfactory discrimination task, rats were trained to associate 2 olfactory stimuli with different responses depending on visuospatial context. Temporary lesions of the AON or vHC impaired performance on this task. In contrast, such lesions did not impair performance on a noncontextual olfactory discrimination task. Moreover, vHC lesions also impaired performance on an analo...
Read Article
Investigation of the cortical activity during episodic future thinking in schizophrenia: A functional near-infrared spectroscopy study.
Episodic future thinking (EFT) refers to mental simulation of possible future events, a process that mostly depends on episodic memory (EM). EFT impairment in schizophrenia was proposed to disturb continuity in self-functioning. Schizophrenia patients are also impaired in EM as well as executive functions (EFs). In the present study, we aimed to clarify the relationship between EFT and memory functions in schizophrenia by assessing (a) whether a group of individuals with schizophrenia (schizophrenia group [SG]) who have relatively intact long-term memory functions differ from healthy controls (control group [CG]) in terms of EFT performance, and (b) whether such difference is biologically re...
Read Article
Gestational exposure to a ketogenic diet increases sociability in CD-1 mice.
Postnatal administration of high-fat, low-carbohydrate ketogenic diets (KDs) is an established and effective treatment option for refractory epilepsy, with more recently identified therapeutic potential across a wide range of preclinical models of neurological and psychiatric disorders. However, the impact of gestational exposure to a KD (GKD) on offspring development remains unclear. Previous work has found that GKD exposure reduces depression- and anxiety-like behaviors in CD-1 mice, whereas postnatal KD improves sociability in several different rodent models of autism. Here we examined how sociability is impacted by GKD. Given that the neuropeptide oxytocin positively regulates affect, an...
Read Article