Transfluthrin- and prallethrin-based insecticides elicit specific enzymatic antioxidant responses in different tissue of zebrafish.

Pyrethroids prallethrin (P-BI) and transfluthrin (T-BI) are among the most commonly used molecules with insecticide action. These molecules comprise different formulations of insecticides largely used in household, agricultural, and animal production fields. However, the increased use of these molecules has led to concerns regarding their safety in animals and humans.

Household based-pyrethroids on adult zebrafish (Danio rerio) exert behavioral and cholinergic changes in different brain regions.

Pyrethroid-based insecticides are largely used for mosquito control. These compounds have household and agricultural applications with different formulations. Two important compounds used as household insecticides are prallethrin and transfluthrin, both from the pyrethroid chemical group.

Pyriproxyfen Exposure Impairs Cognitive Parameters and Alters Cortisol Levels in Zebrafish.

Pyriproxyfen is one of the most used larvicides and insecticides; it acts as an analog of juvenile insect hormone (a growth regulator). It is highly toxic during all stages of mosquito development, suppresses metamorphosis, and interferes in insect reproduction and proliferation. Pyriproxyfen and its main metabolite have been shown to affect brain development in rodents.

Novel object recognition and object location tasks in zebrafish: Influence of habituation and NMDA receptor antagonism.

This study aims to establish a protocol for evaluating the object recognition memory and object location tasks in zebrafish. We evaluated novel the object recognition memory and analyzed the exploration time of the objects during training and testing. Zebrafish explored more the new object in comparison to the familiar object (61% of exploration time during test session).

Glyphosate and Roundup alter morphology and behavior in zebrafish.

Glyphosate has become the most widely used herbicide in the world, due to the wide scale adoption of transgenic glyphosate resistant crops after its introduction in 1996. Glyphosate may be used alone, but it is commonly applied as an active ingredient of the herbicide Roundup. This pesticide contains several adjuvants, which may promote an unknown toxicity.

Enhanced motivation to alcohol in transgenic mice expressing human α-synuclein.

α-Synuclein (αSYN) is the neuropathological hallmark protein of Parkinson's disease (PD) and related neurodegenerative disorders. Moreover, the gene encoding αSYN (SNCA) is a major genetic contributor to PD. Interestingly, independent genome-wide association studies also identified SNCA as the most important candidate gene for alcoholism.

Sex and the housing: Effects on behavior, cortisol levels and weight in zebrafish.

Studies with zebrafish use acclimatizing periods of at least one week immediately before the experiments. During this time, animals can be housed in sexually segregated conditions (only females or males in the tank) or in mixed-sex conditions (both sexes in the tank). The influence of sex and housing conditions regarding the presence of one or two sexes is largely unknown in zebrafish.

A phosphodiesterase 4-controlled switch between memory extinction and strengthening in the hippocampus.

Established fear-related memories can undergo phenomena such as extinction or reconsolidation when recalled. Extinction probably involves the creation of a new, competing memory trace that decreases fear expression, whereas reconsolidation can mediate memory maintenance, updating, or strengthening. The factors determining whether retrieval will initiate extinction, reconsolidation, or neither of these two processes include training intensity, duration of the retrieval session, and age of the memory.

Inhibition of protein synthesis or mTOR in the basolateral amygdala blocks retrieval-induced memory strengthening.

Fear memory retrieval can lead to either reconsolidation (accompanied or not by strengthening of the memory trace) or extinction. Here, we show that non-reinforced retrieval of inhibitory avoidance (IA) conditioning can induce memory strengthening assessed in a subsequent retention test trial. Infusion of the protein synthesis inhibitor cycloheximide or the mTOR inhibitor rapamycin into the rat basolateral complex of the amygdala (BLA) after a reactivation (retrieval) session impaired retrieval-induced strengthening.

Administration of the phosphodiesterase type 4 inhibitor rolipram into the amygdala at a specific time interval after learning increases recognition memory persistence.

Here we show that administration of the phosphodiesterase type 4 (PDE4) inhibitor rolipram into the basolateral complex of the amygdala (BLA) at a specific time interval after training enhances memory consolidation and induces memory persistence for novel object recognition (NOR) in rats. Intra-BLA infusion of rolipram immediately, 1.5 h, or 6 h after training had no effect on retention tested at 1, 7, and 14 d later.

Impairment of object recognition memory by rapamycin inhibition of mTOR in the amygdala or hippocampus around the time of learning or reactivation.

The role of the basolateral complex of the amygdala (BLA) in recognition memory remains poorly understood. The mammalian target of rapamycin (mTOR) in the BLA and other brain areas has been implicated in synaptic plasticity and memory. We have recently shown that mTOR signaling in both the BLA and the dorsal hippocampus (DH) is required for formation and reconsolidation of inhibitory avoidance, a fear-motivated memory task.

Inhibition of mTOR by rapamycin in the amygdala or hippocampus impairs formation and reconsolidation of inhibitory avoidance memory.

Mammalian target of rapamycin (mTOR), a central regulator of protein synthesis in neurons, has been implicated in synaptic plasticity and memory. Here we show that mTOR inhibition by rapamycin in the basolateral amygdala (BLA) or dorsal hippocampus (DH) impairs both formation and reconsolidation of memory for inhibitory avoidance (IA) in rats. Male Wistar rats received bilateral infusions of vehicle or rapamycin into the BLA or DH before or after IA training or retrieval.

Effect of mangiferin, a naturally occurring glucoxylxanthone, on fear memory in rats.

Mangiferin (1,3,6,7-tetrahydroxy-2-[3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl] -xanthen-9-one, CAS 4773-96-0), a naturally occurring glucosylxanthone, is widely distributed in higher plants and a constituent of folk medicine. In the present study the effect of systemic administration of mangiferin on behavioural outcomes of neurological function in normal rats was investigated. A single intraperitoneal injection of mangiferin (10, 50 and 100 mg/kg body weight) immediately post-training produced an impairment of long-term memory for aversive training and a reduced freezing in a dose independent manner, when given immediately post-training.

Posttraining systemic administration of the histone deacetylase inhibitor sodium butyrate ameliorates aging-related memory decline in rats.

Here we show that a systemic injection of the histone deacetylase inhibitor (HDACi) sodium butyrate (NaB) ameliorated an aging-associated deficit in object recognition memory in rats when the injection was given immediately, but not 6h after training. NaB had no effect in younger rats with normal memory retention. The results indicate that HDACis can ameliorate aging-related memory impairments by influencing the early consolidation phase of memory formation.

Mangiferin, a naturally occurring glucoxilxanthone improves long-term object recognition memory in rats.

Mangiferin (2-beta-D-glucopyranosyl-1,3,6,7-tetrahydroxyxanthone) is a xanthone widely distributed in higher plants showing antioxidative, antiviral, anticancer, antidiabetic, immunomodulatory, hepatoprotective, and analgesic effects. In the present study, we have investigated the effects of systemic administration of mangiferin on behavioral outcomes of neurological function in normal rats. A single intraperitoneal injection of mangiferin (10, 50, or 100mg/kg body weight) enhanced novel object recognition (NOR) memory when given immediately post-training.

A Valepotriate Fraction of Valeriana glechomifolia Shows Sedative and Anxiolytic Properties and Impairs Recognition But Not Aversive Memory in Mice.

Plants of the genus Valeriana (Valerianaceae) are used in traditional medicine as a mild sedative, antispasmodic and tranquilizer in many countries. This study was undertaken to explore the neurobehavioral effects of systemic administration of a valepotriate extract fraction of known quantitative composition of Valeriana glechomifolia (endemic of southern Brazil) in mice. Adult animals were treated with a single intraperitoneal injection of valepotriate fraction (VF) in the concentrations of 1, 3 or 10 mg kg(-1), or with vehicle in the pre-training period before each behavioral test.

Systemic administration of doxorubicin impairs aversively motivated memory in rats.

There is growing clinical evidence of cognitive impairment in cancer patients treated with chemotherapy, especially in women treated with drug combinations for breast cancer. Clinical studies have a difficult task of defining which drugs individually are responsible for the cognitive changes and published papers evaluating single agents in experimental models are scanty. In the present study we have investigated the effect of single escalating doses of doxorubicin (DOX) on memory for inhibitory avoidance conditioning (IA) in rats.

Modulation of long-term memory for object recognition via HDAC inhibition.

Histone acetylation is a chromatin modification critically involved in gene regulation during many neural processes. The enzymes that regulate levels of histone acetylation are histone acetyltransferases (HATs), which activate gene expression and histone deacetylases (HDACs), that repress gene expression. Acetylation together with other histone and DNA modifications regulate transcription profiles for specific cellular functions.

Alterations in oxidative markers in the cerebellum and peripheral organs in MPS I mice.

Mucopolysaccharidosis type I is a lysosomal storage disease with alterations in several organs. Little is known about the pathways that lead to the pathology. Evidences point oxidative stress on lysosomal storage diseases and mucopolysaccharidosis type I.

An organic selenium compound attenuates apomorphine-induced stereotypy in mice.

Selenium compounds display neuroprotective activities mediated at least in part by their antioxidant actions. Oxidative damage has been implicated in psychiatric disorders including schizophrenia and bipolar disorder, and an alteration in expression of selenium-binding protein-1 (SELENBP-1) has been recently reported in both the blood and brain of schizophrenic patients. In the present study we examined the effects of the organic selenium compound 3'3-ditrifluoromethyldiphenyl diselenide [(F3CPhSe)2] on apomorphine-induced stereotypy in mice, an animal model of psychosis.

Long-term memory for aversive training is impaired in Idua(-/-) mice, a genetic model of mucopolysaccharidosis type I.

Mucopolysaccharidosis type I (MPS I) is a lysosomal storage disease that leads to neurodegeneration and neurological deficits, among other pathological and clinical consequences. The aim of the present study was to evaluate neurobehavioral parameters in a genetic mouse model of mucopolysaccharidosis type I (MPS I). During exploration of an open field, adult MPS I (Idua(-/-)) mice showed normal locomotion and anxiety but reduced number of rearings.

NMDA receptors mediate consolidation of contextual memory in the hippocampus after context preexposure.

Male Wistar rats received bilateral infusions of vehicle (VEH) or aminophosphonopentanoic acid (AP5), an N-metil-D-aspartate (NMDA) receptor antagonist, into the dorsal hippocampus immediately after inhibitory avoidance (IA) training. Intrahippocampal infusion of AP5 blocked 24 h IA retention. In the second experiment, animals were preexposed to the IA training context 24 h prior to training and received an infusion of either VEH or AP5 immediately after the preexposure trial and a second infusion of VEH or AP5 immediately after IA training.