Regulation Of Locomotor Activity Research Articles

Genetically defined nucleus incertus neurons differ in connectivity and function.

The nucleus incertus (NI), a conserved hindbrain structure implicated in the stress response, arousal, and memory, is a major site for production of the neuropeptide relaxin-3. On the basis of goosecoid homeobox 2 (gsc2) expression, we identified a neuronal cluster that lies adjacent to relaxin 3a (rln3a) neurons in the zebrafish analogue of the NI. To delineate the characteristics of the gsc2 and rln3a NI neurons, we used CRISPR/Cas9 targeted integration to drive gene expression specifically in each neuronal group, and found that they differ in their efferent and afferent connectivity, spontaneous activity, and functional properties. gsc2 and rln3a NI neurons have widely divergent projection patterns and innervate distinct subregions of the midbrain interpeduncular nucleus (IPN). Whereas gsc2 neurons are activated more robustly by electric shock, rln3a neurons exhibit spontaneous fluctuations in calcium signaling and regulate locomotor activity. Our findings define heterogeneous neurons in the NI and provide new tools to probe its diverse functions.

Inhibitory medial zona incerta pathway drives exploratory behavior by inhibiting glutamatergic cuneiform neurons

The cuneiform nucleus (CnF) regulates locomotor activity, which is canonically viewed as being primarily involved in initiating locomotion and regulating speed. Recent research shows greater context dependency in the locomotor functions of this nucleus. Glutamatergic neurons, which contain vesicular glutamate transporter 2 (vGLUT2), regulate context-dependent locomotor speed in the CnF and play a role in defensive behavior. Here, we identify projections from the medial zona incerta (mZI) to CnF vGLUT2 neurons that promote exploratory behavior. Using fiber photometry recordings in male mice, we find that mZI gamma-aminobutyric acid (GABA) neurons increase activity during periods of exploration. Activation of mZI GABAergic neurons is associated with reduced spiking of CnF neurons. Additionally, activating both retrogradely labeled mZI-CnF GABAergic projection neurons and their terminals in the CnF increase exploratory behavior. Inhibiting CnF vGLUT2 neuronal activity also increases exploratory behavior. These findings provide evidence for the context-dependent dynamic regulation of CnF vGLUT2 neurons, with the mZI-CnF circuit shaping exploratory behavior.

Spatial distribution and circadian locomotor activity of invasive armored catfish (Loricariidae) in the freshwater and brackish water.

Invasive suckermouth armored catfish Pterygoplichthys spp. successfully spread during one decade into many river systems of Vietnam. Wide and rapid invasion of armored catfish might be associated with using brackish water in estuaries to spread from one river system to another. The first goal of our study was to assess the horizontal and vertical distribution of invasive fish in freshwater (Da Rang River) and in brackish water (Da Rang River estuary) associated with circadian rhythm. In the both sampling locations, fish were mainly caught at nighttime at the bottom and near the surface using the net traps and vertical nets. In estuary, fish were caught in the net traps with distance 2.0-7.5 m from the right or left banks where water was predominantly fresh. In freshwater of the Da Rang River, fish were often caught near the left bank with gravel and stone substrate. The second goal of our study was to experimentally evaluate the circadian (12 hours of the night and 12 hours of the day) rhythm of locomotor activity (LA) of fish. Fish from different freshwater locations (Am Chua canal and Da Rang River) had a similar diurnal dynamic of LA with mostly movements (77-83% of total diurnal LA) at nighttime (18:00-6:00, GMT+7) at the end of the wet season. Armored catfish from the brackish water location (Da Rang River estuary) also were mostly active (76% of total diurnal LA) overnight. However, fish from freshwater and brackish water had difference in the timing of behavioral activity. Fish LA from estuary was significantly lower than LA of fish from freshwater locations during 18:00 to 21:00 before low tide. The results of our field and experimental studies established that armored catfish in estuary moved in horizontal and vertical planes predominantly at nighttime. Tide level regulates locomotor activity of invasive fish and could influence on the possibility of their spreading through the estuary.

THU125 Altered Pro-opiomelanocortin (POMC) Neuron Function Characterizes Energy Expenditure Dysfunction And Increased Body Weight Linked To Fragile X Gene Mutation

Abstract Disclosure: R.E. Ruggiero-Ruff: None. P. Villa: None. S. Abu Hijleh: None. B. Avalos: None. N. DiPatrizio: None. D. Coss: None. Obesity is a world-wide epidemic that has become a major public health concern. Obesity increases the risk of cardiovascular disease, type 2 diabetes, stroke, and dementia. Children and adolescents with Fragile X syndrome (FXS), the most common cause of inherited intellectual disability, have higher rates of obesity compared to peers. FXS is caused by a mutation of the Fragile X messenger ribonucleoprotein gene (FMR1), which leads to the loss of FMRP, a ubiquitously expressed mRNA binding protein. Food intake and energy expenditure are regulated by orexigenic neuropeptide Y (NPY)/agouti-related protein (AgRP) and anorexigenic pro-opiomelanocortin (POMC) neurons from the hypothalamus. While our understanding of mechanisms of intellectual disability in FXS patients is beginning to emerge, the role of FMR1 gene in the hypothalamus is unknown. In this study, we used a knock-out (KO) mouse model to analyze if obesity in FXS patients stems from dysregulation of the hypothalamic circuitry regulating food intake and energy expenditure. Consistent with what is seen in the human population, KO males weigh more than their WT littermates. There were no differences in growth hormone or basal or fasting glucose levels. There was no difference in food intake, however KO males exhibited lower locomotor activity in the dark cycle, during their active phase. Since POMC neurons regulate energy expenditure in addition to food intake, we analyzed POMC neuron number, using immunohistochemistry. We determined fewer POMC neurons in KO male mice compared to WT. AgRP/NPY neurons modulate POMC neurons through GABAergic neuronal transmission. We determined that KO males have increased obligatory GABAa receptor subunit on POMC neurons. We also analyzed GABAa receptor and vesicular GABA transporter (VGAT) apposition on POMC neurons to identify synaptic receptors and indeed, KO males had significantly higher levels of GABAa-VGAT appositions, indicating increased synaptic input. In summary, our results suggest a role for FMR1 in the regulation of POMC neuronal activity in the regulation of locomotor activity and point to a role in modulating motor activity and energy expenditure in obese Fragile X patients. Presentation: Thursday, June 15, 2023

Optogenetic cleavage of the Miro GTPase reveals the direct consequences of real-time loss of function in Drosophila.

Miro GTPases control mitochondrial morphology, calcium homeostasis, and regulate mitochondrial distribution by mediating their attachment to the kinesin and dynein motor complex. It is not clear, however, how Miro proteins spatially and temporally integrate their function as acute disruption of protein function has not been performed. To address this issue, we have developed an optogenetic loss of function "Split-Miro" allele for precise control of Miro-dependent mitochondrial functions in Drosophila. Rapid optogenetic cleavage of Split-Miro leads to a striking rearrangement of the mitochondrial network, which is mediated by mitochondrial interaction with the microtubules. Unexpectedly, this treatment did not impact the ability of mitochondria to buffer calcium or their association with the endoplasmic reticulum. While Split-Miro overexpression is sufficient to augment mitochondrial motility, sustained photocleavage shows that Split-Miro is surprisingly dispensable to maintain elevated mitochondrial processivity. In adult fly neurons in vivo, Split-Miro photocleavage affects both mitochondrial trafficking and neuronal activity. Furthermore, functional replacement of endogenous Miro with Split-Miro identifies its essential role in the regulation of locomotor activity in adult flies, demonstrating the feasibility of tuning animal behaviour by real-time loss of protein function.

Burrow emergence rhythms of deep-water Mediterranean Norway lobsters (Nephrops norvegicus) revealed by acoustic telemetry

N. norvegicus supports one of the most commercially-important fisheries in the Mediterranean, and there is considerable interest in developing non-invasive sampling stock assessment methods. Currently, stock assessments are conducted via trawling or by UnderWater TeleVision (UWTV) surveys with limited capacity to provide direct population data due to the burrowing behavior of the species. Here, we used acoustic telemetry to characterize the burrow emergence and movement patterns of N. norvegicus in relation to internal tides and inertial currents in deep-sea habitats of the northwestern Mediterranean. We deployed acoustic tags on 25 adults between May and June 2019, and collected up to 4 months of detection data from each tag. Tagged lobsters spent approximately 12% of their time in door-keeping (i.e., detections at burrow entrance with no displacements) but differences existed among the different behavioral rhythms identified. We observed that mixed day-night, tidal and inertial rhythms in field settings were similar to those observed in laboratory tests. The presence of mixed day-night and tidal periodicity poses the question of why N. norvegicus exhibits flexible responses to environmental cues other than photoperiod. It is possible that tidal regulation of locomotor activity could reduce energy expenditure in relation to hydrodynamic drag. Inertial periodicity occurs in animals with no clear burrowing-oriented activity (always present on the seabed). Possibly, inertial-related movements are the result of a disruption of the biological clock. Our results are discussed in the context of how burrow emergence rhythms may bias UWTV surveys and how novel in situ monitoring approaches address these biases.

Synaptic scaling of corticostriatal circuits underlies hyperactivity in GABA Transporter-1 deficient mice

Homeostatic synaptic scaling entails adjustment of synaptic strength on a cell to prolonged changes of neuronal activity, which is postulated to participate in neuropsychiatric disorders invivo. Here, we find that sustained elevation in ambient GABA levels, by either genetic deletion or pharmacological blockade of GABA transporter-1 (GAT1), leads to synaptic scaling up of corticostriatal pathways, which underlies locomotor hyperactivity. Meanwhile, medium spinyneurons of the dorsal striatum exhibit an aberrant increase in excitatory synaptic transmission and corresponding structural changes in dendritic spines. Mechanistically, GAT1 deficiency dampens the expression and function of metabotropic glutamate receptors (mGluRs) and endocannabinoid (eCB)-dependent long-term depression of excitatory transmission. Conversely, restoring mGluR function in GAT1 deficient mice rescues excitatory transmission. Lastly, pharmacological potentiation of mGluR-eCB signaling or inhibition of homomeric-GluA1 AMPA receptors eliminates locomotor hyperactivity in the GAT1 deficient mice. Together, these results reveal a synaptic scaling mechanism in corticostriatal pathways that regulate locomotor activity.

Increased locomotor activity via regulation of GABAergic signalling in foxp2 mutant zebrafish\u2014implications for neurodevelopmental disorders

Recent advances in the genetics of neurodevelopmental disorders (NDDs) have identified the transcription factor FOXP2 as one of numerous risk genes, e.g. in autism spectrum disorders (ASD) and attention-deficit/hyperactivity disorder (ADHD). FOXP2 function is suggested to be involved in GABAergic signalling and numerous studies demonstrate that GABAergic function is altered in NDDs, thus disrupting the excitation/inhibition balance. Interestingly, GABAergic signalling components, including glutamate-decarboxylase 1 (Gad1) and GABA receptors, are putative transcriptional targets of FOXP2. However, the specific role of FOXP2 in the pathomechanism of NDDs remains elusive. Here we test the hypothesis that Foxp2 affects behavioural dimensions via GABAergic signalling using zebrafish as model organism. We demonstrate that foxp2 is expressed by a subset of GABAergic neurons located in brain regions involved in motor functions, including the subpallium, posterior tuberculum, thalamus and medulla oblongata. Using CRISPR/Cas9 gene-editing we generated a novel foxp2 zebrafish loss-of-function mutant that exhibits increased locomotor activity. Further, genetic and/or pharmacological disruption of Gad1 or GABA-A receptors causes increased locomotor activity, resembling the phenotype of foxp2 mutants. Application of muscimol, a GABA-A receptor agonist, rescues the hyperactive phenotype induced by the foxp2 loss-of-function. By reverse translation of the therapeutic effect on hyperactive behaviour exerted by methylphenidate, we note that application of methylphenidate evokes different responses in wildtype compared to foxp2 or gad1b loss-of-function animals. Together, our findings support the hypothesis that foxp2 regulates locomotor activity via GABAergic signalling. This provides one targetable mechanism, which may contribute to behavioural phenotypes commonly observed in NDDs.

Two Players in the Field: Hierarchical Model of Interaction between the Dopamine and Acetylcholine Signaling Systems in the Striatum.

Tight interactions exist between dopamine and acetylcholine signaling in the striatum. Dopaminergic neurons express muscarinic and nicotinic receptors, and cholinergic interneurons express dopamine receptors. All neurons in the striatum are pacemakers. An increase in dopamine release is activated by stopping acetylcholine release. The coordinated timing or synchrony of the direct and indirect pathways is critical for refined movements. Changes in neurotransmitter ratios are considered a prominent factor in Parkinson’s disease. In general, drugs increase striatal dopamine release, and others can potentiate both dopamine and acetylcholine release. Both neurotransmitters and their receptors show diurnal variations. Recently, it was observed that reward function is modulated by the circadian system, and behavioral changes (hyperactivity and hypoactivity during the light and dark phases, respectively) are present in an animal model of Parkinson’s disease. The striatum is one of the key structures responsible for increased locomotion in the active (dark) period in mice lacking M4 muscarinic receptors. Thus, we propose here a hierarchical model of the interaction between dopamine and acetylcholine signaling systems in the striatum. The basis of this model is their functional morphology. The next highest mode of interaction between these two neurotransmitter systems is their interaction at the neurotransmitter/receptor/signaling level. Furthermore, these interactions contribute to locomotor activity regulation and reward behavior, and the topmost level of interaction represents their biological rhythmicity.

Health inequality and COVID-19: the culmination of two centuries of social murder.

<h3>ABSTRACT</h3> Miro GTPases control mitochondrial morphology, calcium homeostasis and regulate mitochondrial distribution by mediating their attachment to the kinesin and dynein motor complex. It is not clear, however, how Miro proteins spatially and temporally integrate their function as acute disruption of protein function has not been performed. To address this issue, we have developed an optogenetic loss of function ‘Split-Miro’ allele for precise control of Miro-dependent mitochondrial functions in <i>Drosophila</i>. Rapid optogenetic cleavage of Split-Miro leads to a striking rearrangement of the mitochondrial network, which is mediated by mitochondrial interaction with the microtubules. Unexpectedly, this treatment did not impact the ability of mitochondria to buffer calcium. While Split-Miro overexpression is sufficient to augment mitochondrial motility, sustained photocleavage shows Split-Miro is surprisingly dispensable to maintain elevated mitochondrial processivity. Furthermore, functional replacement of endogenous Miro with Split-Miro identifies its essential role in the regulation of locomotor activity in adult flies, demonstrating the feasibility of tuning animal behaviour by real-time loss of protein function.

2027-P: Dietary Cholesterol and Neuropeptide Agouti Related Peptide Act in Concert to Regulate Locomotor Activity

In an ever-changing environment where food availability is highly unpredictable, the ability to maintain energy homeostasis requires proper sensing of dietary macronutrients, and subsequent adaptive adjustments in feeding behavior. Cholesterol is an important macronutrient, but cytotoxic in excess. Thus, cholesterol metabolism is under tight homeostatic regulation. Cholesterol is a major precursor of bile acids. After a meal, bile acids are released into the intestine and stimulate the secretion of fibroblast growth factor 15/19 (FGF-15/19). FGF-15/19 is an enterokine known to specifically suppress Agouti-related protein (AgRP), a neuropeptide of the central melanocortin system (CMS) that increases with fasting and promotes feeding and locomotor activity. Studies show that the CMS plays a modulatory role in hepatic cholesterol metabolism. However, the effects of dietary cholesterol on feeding behavior and energy homeostasis have remained largely unexplored. In this study, we found, surprisingly, that dietary cholesterol modulates expression of AgRP. Specific removal of cholesterol from the diets of wild type mice under ad-lib conditions leads to increased hypothalamic Agrp, but not Npy, mRNA expression. Furthermore, these mice also have low intestinal fGF-15mRNA expression. Cholesterol deficiency also leads to increased locomotor activities, an effect that is AgRP dependent as locomotor activity in AgRP knockout mice is unaffected by alterations in dietary cholesterol content. In wild type mice, fasting induces increased locomotor activity, which is widely thought to be a proxy for food seeking behavior. Notably, we observe dietary cholesterol content has no effect on ad-libfood intake, suggesting food seeking behaviors may be uncoupled from food intake. Taken together, these results suggest a novel paradigm where dietary cholesterol can act as a peripheral nutrient signal that can ultimately affect locomotor activity and possibly food seeking behavior. Disclosure A. Huang: None. M.T. Maier: None. A. Xu: None.

Drosophila Temperature Preference Rhythms: An Innovative Model to Understand Body Temperature Rhythms.

Human body temperature increases during wakefulness and decreases during sleep. The body temperature rhythm (BTR) is a robust output of the circadian clock and is fundamental for maintaining homeostasis, such as generating metabolic energy and sleep, as well as entraining peripheral clocks in mammals. However, the mechanisms that regulate BTR are largely unknown. Drosophila are ectotherms, and their body temperatures are close to ambient temperature; therefore, flies select a preferred environmental temperature to set their body temperature. We identified a novel circadian output, the temperature preference rhythm (TPR), in which the preferred temperature in flies increases during the day and decreases at night. TPR, thereby, produces a daily BTR. We found that fly TPR shares many features with mammalian BTR. We demonstrated that diuretic hormone 31 receptor (DH31R) mediates Drosophila TPR and that the closest mouse homolog of DH31R, calcitonin receptor (Calcr), is essential for mice BTR. Importantly, both TPR and BTR are regulated in a distinct manner from locomotor activity rhythms, and neither DH31R nor Calcr regulates locomotor activity rhythms. Our findings suggest that DH31R/Calcr is an ancient and specific mediator of BTR. Thus, understanding fly TPR will provide fundamental insights into the molecular and neural mechanisms that control BTR in mammals.

Kisspeptin Neurons in the Arcuate Nucleus of the Hypothalamus Orchestrate Circadian Rhythms and Metabolism

Successful reproduction in female mammals is precisely timed and must be able to withstand the metabolic demand of pregnancy and lactation. We show that kisspeptin-expressing neurons in the arcuate hypothalamus (Kiss1ARH) of female mice control thedaily timing of food intake, along with the circadian regulation of locomotor activity, sleep, and core body temperature. Toxin-induced silencing of Kiss1ARH neurons shifts wakefulness and food consumption to the light phase and induces weight gain. Toxin-silenced mice are less physically active and have attenuated temperature rhythms. Because the rhythm of the master clock in the suprachiasmatic nucleus (SCN) appears to be intact, we hypothesize that Kiss1ARH neurons signal to neurons downstream of the master clock to modulate the output of the SCN. We conclude that, in addition to their well-established role in regulating fertility, Kiss1ARH neurons are a critical component of the hypothalamic circadian oscillator network that times overt rhythms of physiology and behavior.

The clock components Period2, Cryptochrome1a, and Cryptochrome2a function in establishing light-dependent behavioral rhythms and/or total activity levels in zebrafish

The circadian clock generates behavioral rhythms to maximize an organism’s physiological efficiency. Light induces the formation of these rhythms by synchronizing cellular clocks. In zebrafish, the circadian clock components Period2 (zPER2) and Cryptochrome1a (zCRY1a) are light-inducible, however their physiological functions are unclear. Here, we investigated the roles of zPER2 and zCRY1a in regulating locomotor activity and behavioral rhythms. zPer2/zCry1a double knockout (DKO) zebrafish displayed defects in total locomotor activity and in forming behavioral rhythms when briefly exposed to light for 3-h. Exposing DKO zebrafish to 12-h light improved behavioral rhythm formation, but not total activity. Our data suggest that the light-inducible circadian clock regulator zCRY2a supports rhythmicity in DKO animals exposed to 12-h light. Single cell imaging analysis revealed that zPER2, zCRY1a, and zCRY2a function in synchronizing cellular clocks. Furthermore, microarray analysis of DKO zebrafish showed aberrant expression of genes involved regulating cellular metabolism, including ATP production. Overall, our results suggest that zPER2, zCRY1a and zCRY2a help to synchronize cellular clocks in a light-dependent manner, thus contributing to behavioral rhythm formation in zebrafish. Further, zPER2 and zCRY1a regulate total physical activity, likely via regulating cellular energy metabolism. Therefore, these circadian clock components regulate the rhythmicity and amount of locomotor behavior.

Carnosine restores aging-induced elevation of corticosterone status and brain regional amyloid-beta in relation to down regulation of locomotor activity

Carnosine restores aging-induced elevation of corticosterone status and brain regional amyloid-beta in relation to down regulation of locomotor activity

Molecular and circuit mechanisms mediating circadian clock output in the Drosophila brain.

A central question in the circadian biology field concerns the mechanisms that translate ~24-hr oscillations of the molecular clock into overt rhythms. Drosophila melanogaster is a powerful system that provided the first understanding of how molecular clocks are generated and is now illuminating the neural basis of circadian behavior. The identity of ~150 clock neurons in the Drosophila brain and their roles in shaping circadian rhythms of locomotor activity have been described before. This review summarizes mechanisms that transmit time-of-day signals from the clock, within the clock network as well as downstream of it. We also discuss the identification of functional multisynaptic circuits between clock neurons and output neurons that regulate locomotor activity.

NonA and CPX Link the Circadian Clockwork to Locomotor Activity in Drosophila

Drosophila NonA and its mammalian ortholog NONO are members of the Drosophila behavior and human splicing (DBHS) family. NONO also has a strong circadian connection: it associates with the circadian repressor protein PERIOD (PER) and contributes to circadian timekeeping. Here, we investigate NonA, which is required for proper levels of evening locomotor activity as well as a normal free-running period in Drosophila. NonA is associated with the positive transcription factor CLOCK/CYCLE (CLK/CYC), interacts directly with complexin (cpx) pre-mRNA, and upregulates gene expression, including the gene cpx. Downregulation of cpx expression in circadian neurons phenocopies NonA downregulation, whereas cpx overexpression rescues the nonA RNAi phenotypes, indicating that cpx is an important NonA target gene. As the cpx protein contributes to proper neurotransmitter and neuropeptide release in response to calcium, these results and others indicate that this control is important for the normal circadian regulation of locomotor activity.

Regulation of Locomotor activity in fed, fasted, and food-restricted mice lacking tissue-type plasminogen activator

BackgroundCircadian rhythms of physiology and behavior are driven by a circadian clock located in the suprachiasmatic nucleus of the hypothalamus. This clock is synchronized to environmental day/night cycles by photic input, which is dependent on the presence of mature brain-derived neurotrophic factor (BDNF) in the SCN. Mature BDNF is produced by the enzyme plasmin, which is converted from plasminogen by the enzyme tissue-type plasminogen activator (tPA). In this study, we evaluate circadian function in mice lacking functional tPA.ResultstPA−/− mice have normal circadian periods, but show decreased nocturnal wheel-running activity. This difference is eliminated or reversed on the second day of a 48-h fast. Similarly, when placed on daily cycles of restricted food availability the genotypic difference in total wheel-running activity disappears, and tPA−/− mice show equivalent amounts of food anticipatory activity to wild type mice.ConclusionsThese data suggest that tPA regulates nocturnal wheel-running activity, and that tPA differentially affects SCN-driven nocturnal activity rhythms and activity driven by fasting or temporal food restriction.

M(4) muscarinic receptors and locomotor activity regulation.

M(4) muscarinic receptors (M(4) MR) represent a subfamily of G-protein coupled receptors serving a substantial role in spontaneous locomotor activity regulation, cognition and modulation of cholinergic system. With increasing body of literature discussing the role of M(4) MR some controversies arose. Thus, we try here to summarize the current evidence regarding the M(4) MR, with the special focus on their role in Locomotor activity control. We review the molecular function of M(4) MR in specific brain areas implicated in locomotor regulation, and shortly in other CNS processes that could be connected to locomotor activity. We also focus on brain areas implicated in locomotor activity biorhythm changes like suprachiasmatic nucleus, subparaventricular zone posterior hypothalamic area, striatum and thalamus. Gender-related aspects and differences in locomotor activity in males and females are discussed further.

Behavioral impairments following repeated intranasal glyphosate-based herbicide administration in mice

Inhalation or intranasal (IN) administration of neurotoxicants could constitute a route of toxin delivery to the brain. Pesticides have been proposed as the main environmental factor associated with the etiology of neurodegenerative disorders. In Argentina, the area used for glyphosate (Gly)-resistant crops are sprayed annually with ~200 million liters of Gly-based herbicides (Gly-BHs). Gly residues are often found in the environment, and considering the frequency and amount of its applications, it is probable that the inhalation of Gly-BHs occurs. The present study investigates the neurobehavioral effects of repeated IN administration of Gly-BH in male CF-1 mice (~2mg/nostrils/day) three days a week, during four weeks (50mg/kg/day). Locomotor activity and anxiety levels were studied by the Open Field (OF) test. Anxiety was also analyzed through the plus maze (PM) test. Novel Object Recognition (NOR) test was used for recognition memory analysis. Repeated IN Gly-BH administration in mice decreased the ambulatory activity. Moreover, Gly-BH treated mice showed a pronounced increase in thigmotaxis, compared to control group, indicating higher anxiety levels. The anxiogenic behavior in Gly-BH treated mice was then confirmed by PM test. The recognition memory was significantly impaired after 6h in the Gly-BH treated group. No differences were observed between both groups when the NOR test was performed 24h after. The present study reveals that repeated IN exposure to Gly-BH in mice affects the central nervous system probably altering neurotransmission pathways that participate or regulate locomotor activity, anxiety and memory.