Cognitive tests on representative groups of freely behaving transgenic mice are shown to enable a quantitative characterization of reconnectable implantable fiber-optic neurointerfaces for optogenetic neurostimulation. A systematic analysis of such tests provides a robust quantitative measure for the cognitive effects induced by fiber-optic neurostimulation, validating the performance of fiber-optic neurointerfaces for long-term optogenetic brain stimulations and showing no statistically significant artifacts in the behavior of transgenic mice due to interface implantation.
Accumulation of c-Fos and Arc proteins in neurons in different regions of the hippocampus after single trial of contextual fear conditioning was studied by using immunohistochemical staining. We found that the dynamics of the c-Fos and Arc expression has a biphasic pattern: the first peak was observed in 15-30 min after learning and the second less pronounced peak in 1-3 h. Induction of Arc occurred earlier than c-Fos and the overall dynamics of the two waves slightly varied in the dentate gyrus and hippocampal CA1 and CA3 fields. The findings open the possibility of mapping the cognitive neural networks of the brain with higher temporal resolution and draw attention to fluctuations of hippocampal activity after a single brief episode of new experience.
The novel synthetic derivative of carnosine, (S)-6-hydroxy-2,5,7,8-tetramethylchroman-2-carbonyl-β-alanyl-L-histidine (S-Trolox™-Carnosine, STC) increases the resistance of rats to experimental acute hypobaric hypoxia (AHH) thus protecting brain from the oxidative damage. This effect is accompanied by better preservation of the acquired skills in Morris water maze possibly by increasing efficiency of the brain antioxidant system. In addition, STC caused an increase in life span of both male and female fruit fly Drosophila melanogaster whereas carnosine increased life span only in male fruit flies. The results indicate that development of the drug based on STC could be beneficial in neurology and gerontology.
In this study, we describe use of Cre-mediated recombination to obtain a
permanent genetic labeling of the brain neuronal networks activated during a
new experience in animals. This method utilizes bitransgenic Fos-Cre-eGFP mice
in which a green fluorescent protein is expressed upon tamoxifen-induced
Cre-recombination only in the cells where immediate early gene c-fos
expression takes place due to the new experience. We used the
classical fear conditioning model to show that ex vivo
microscopy of the eGFP protein in Fos-Cre-eGFP mice enables mapping of
the neurons of the various brain regions that undergo Cre-recombination during
acquisition of a new experience. We exposed the animals to the new environment
in brief sessions and demonstrated that double immunohistochemical staining
enables a characterization of the types of neocortical and hippocampal neurons
that undergo experience-dependent Cre-recombination. Notably, Fos-Cre-eGFP
labeled cells appeared to belong to excitatory pyramidal neurons rather than to
various types of inhibitory neurons. We also showed that a combination of
genetic Cre-eGFP labeling with immunohistochemical staining of the endogenous
c-Fos protein allows one to identify and compare the neuronal populations that
are activated during two different episodes of new experiences in the same
animal. This new approach can be used in a wide spectrum of tasks that require
imaging and a comparative analysis of cognitive neuronal networks.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.