Long-term effects of neonatal basal forebrain cholinergic lesions on radial maze learning and impulsivity in rats

Enhancing cognition through pharmacological and environmental interventions: Examples from preclinical models of neurodevelopmental disorders

In this review we discuss the role of environmental and pharmacological treatments to enhance cognition with special regards to neurodevelopmental related disorders and aging. How the environment influences brain structure and function, and the interactions between rearing conditions and gene expression, are fundamental questions that are still poorly understood. We propose a model that can explain some of the discrepancies in findings for effects of environmental enrichment on outcome measures. Evidence of a direct causal correlation of nootropics and treatments that enhanced cognition also will be presented, and possible molecular mechanisms that include neurotrophin signaling and downstream pathways underlying these processes are discussed. Finally we review recent findings achieved with a wide set of behavioral and cognitive tasks that have translational validity to humans, and should be useful for future work on devising appropriate therapies. As will be discussed, the collective findings suggest that a combinational therapeutic approach of environmental enrichment and nootropics could be particularly successful for improving learning and memory in both developmental disorders and normal aging.

Perinatal 192 IgG-Saporin as Neuroteratogen

The immunotoxin 192 IgG-saporin selectively destroys basal forebrain cholinergic neurons that provide cholinergic input to the hippocampus, entire cortical mantle, amygdala, and olfactory bulb. Perinatal immunotoxic lesions by 192 IgG-saporin induce long-lasting cholinergic depletion mimicking a number of developmental disorders reported in humans. The perinatal injection of 192 IgG-saporin induces several brain modifications, which are observed in neocortex and hippocampus at short and long term. These plastic changes involve both structural (alterations in brain volume, neuronal morphology, and neurogenesis) and molecular (modulations of the levels of neurotransmitters and other proteins related to neurodegeneration) levels. Moreover, the perinatal injection of 192 IgG-saporin may interact with the brain plastic capacity to react to other injuries. Perinatal 192 IgG-saporin lesions allowed investigating the role of the basal forebrain cholinergic system in modulating behavioral functions in developing as well as adult rats. After perinatal cholinergic depletion, rats display reduced ultrasonic vocalizations as neonates, learning and exploratory deficits as juveniles, altered discriminative abilities, impulsive and perseverative behaviors, and memory deficits as adults. Overall, these findings underline the importance of cholinergic system integrity for the development of specific structural and functional features.

A framework for understanding and advancing intertemporal choice research using rodent models

Intertemporal choices are common and consequential to private and public life. Thus, there is considerable interest in understanding the neural basis of intertemporal decision making. In this minireview, we briefly describe conceptual and psychological perspectives on intertemporal choice and then provide a comprehensive evaluation of the neural structures and signals that comprise the underlying cortico-limbic-striatal circuit. Even though great advances have been made, our understanding of the neurobiology of intertemporal choice is still in its infancy because of the complex and dynamic nature of this form of decision making. We close by briefly discussing recommendations for the future study of intertemporal choice research.

Biological activities of ribosome-inactivating proteins and their possible applications as antimicrobial, anticancer, and anti-pest agents and in neuroscience research

Ribosome-inactivating proteins (RIPs) are enzymes which depurinate ribosomal RNA (rRNA), thus impeding the process of translation resulting in inhibition of protein synthesis. They are produced by various organisms including plants, fungi and bacteria. RIPs from plants are linked to plant defense due to their antiviral, antifungal, antibacterial, and insecticidal activities in which they can be applied in agriculture to combat microbial pathogens and pests. Their anticancer, antiviral, embryotoxic, and abortifacient properties may find medicinal applications. Besides, conjugation of RIPs with antibodies or other carriers to form immunotoxins has been found useful to research in neuroscience and anticancer therapy.