Effects of long-lasting social isolation and re-socialization on cognitive performance and brain activity: a longitudinal study in Octodon degus.

Social isolation is considered a stressful situation that results in increased physiological reactivity to novel stimuli, altered behaviour, and impaired brain function. Here, we investigated the effects of long-term social isolation on working memory, spatial learning/memory, hippocampal synaptic transmission, and synaptic proteins in the brain of adult female and male Octodon degus. The strong similarity between degus and humans in social, metabolic, biochemical, and cognitive aspects, makes it a unique animal model that can be highly applicable for further social, emotional, cognitive, and aging studies.

Induction of hypothyroidism during early postnatal stages triggers a decrease in cognitive performance by decreasing hippocampal synaptic plasticity.

Thyroid hormones are vital in the control of multiple body functions, including the correct performance of the brain. Multiple diseases are associated with thyroid gland functioning, including hypothyroidism. To date, little is known regarding the effects of the establishment of this condition at a young age on brain function.

Andrographolide recovers cognitive impairment in a natural model of Alzheimer's disease (Octodon degus).

The social species Octodon degus (degu) is the only wild-type South American rodent that develops Alzheimer's-like pathology with age. Here, we evaluated the ability of a natural product (Andrographolide, ANDRO), a diterpene of the labdane family obtained from the Asian plant Andrographis paniculata, to recover the cognitive decline in this long-lived animal model. We administered ANDRO to aged degus (56-month old) for 3 months.

Wnt-5a-regulated miR-101b controls COX2 expression in hippocampal neurons.

Background: Wnt-5a is a member of the WNT family of secreted lipoglycoproteins, whose expression increases during development; moreover, Wnt-5a plays a key role in synaptic structure and function in the adult nervous system. However, the mechanism underlying these effects is still elusive. MicroRNAs (miRNAs) are a family of small non-coding RNAs that control the gene expression of their targets through hybridization with complementary sequences in the 3' UTR, thereby inhibiting the translation of the target proteins.

ATP induces NO production in hippocampal neurons by P2X(7) receptor activation independent of glutamate signaling.

To assess the putative role of adenosine triphosphate (ATP) upon nitric oxide (NO) production in the hippocampus, we used as a model both rat hippocampal slices and isolated hippocampal neurons in culture, lacking glial cells. In hippocampal slices, additions of exogenous ATP or 2'(3')-O-(4-Benzoylbenzoyl) ATP (Bz-ATP) elicited concentration-dependent NO production, which increased linearly within the first 15 min and plateaued thereafter; agonist EC50 values were 50 and 15 µM, respectively. The NO increase evoked by ATP was antagonized in a concentration-dependent manner by Coomassie brilliant blue G (BBG) or by N(ω)-propyl-L-arginine, suggesting the involvement of P2X7Rs and neuronal NOS, respectively.

Neurosteroids differentially modulate P2X ATP-gated channels through non-genomic interactions.

As neuroactive steroids modulate several ionotropic receptors, we assessed whether the ATP-gated currents elicited by P2X(4) receptors are modulated by these compounds. We transfected HEK293 cells or injected Xenopus laevis oocytes with the cDNA coding for rat P2X(4) receptor. Application of 0.