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1.
Behav Processes ; 210: 104903, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37286113

RESUMEN

Social preference tests can be used to analyze variables that influence and modify social behaviors, and to investigate effects of substances such as medications, drugs, and hormones. They may become important tools for finding a valid model to study neuropsychiatric changes and to study human neurodevelopmental processes that have been impaired by social events. While a preference for conspecifics has been shown for different species, social novelty has been used as a model for anxiety-like behavior in rodents. The goal of this research was to understand the roles of stimulus salience (numerousness) and novelty in social investigation and social novelty tests in zebrafish (Danio rerio Hamilton 1822). We used a sequential design, in which animals are exposed first to a social investigation test (with dichotomous presentation of novel conspecifics vs. empty tank) and then to a social novelty test (with dichotomous presentation of the already known conspecific and a novel conspecific). In experiment 1, animals were presented to either 1 or 3 (vs. an empty tank) conspecifics as stimuli. In experiment 2, animals were presented to 1 vs. 3 conspecifics as stimuli. In experiment 3, animals were observed in the social investigation and social novelty tests for 3 consecutive days. The results showed equivalence between 1 or 3 conspecifics in the social investigation and social novelty tests, although animals were able to discriminate between different shoal sizes. These preferences do not change with repeated test exposure, suggesting novelty to be a minor contributor to social investigation and social novelty in zebrafish.


Asunto(s)
Conducta Social , Pez Cebra , Animales , Humanos , Conducta Animal
2.
Neuropharmacology ; 237: 109620, 2023 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-37263575

RESUMEN

Increased activity in the insula has been consistently reported to be associated with anxiety and anxiety-related disorders. However, little is known on how the insula regulates anxiety. The present study aims at determining the role of the insula on the effects of glucocorticoids in anxiety. A combination of pharmacological manipulations, including blockade of adrenal GC synthesis by metyrapone and intra-insular microinjections of corticosterone, corticosterone-BSA, mineralocorticoid receptor (MR) antagonist spironolactone and glucocorticoid receptor (GR) antagonist mifepristone, were used to assess the short-term (5 min) effects of intra-insular corticosterone in two anxiety-like behaviors in male Sprague-Dawley rats. The elevated plus maze (EPM) and Novelty Suppressed Feeding (hyponeophagia) were utilized. We found that corticosterone in the insula is sufficient to prevent the anxiolytic effects corticosterone synthesis blockade in anxiety, and that intra-insular corticosterone has anxiolytic or anxiogenic effects depending on the amount of corticosterone microinjected and the arousal associated to the test, without affecting the HPA axis. Glucocorticoid anxiolytic effects in the insula are mediated by MRs, while its anxiogenic effects are dependent on a mifepristone-sensitive membrane-bound mechanism. Anxiety appears to be modulated at the insula through a competition between fast MR-dependent anxiolytic and membrane-associated anxiogenic signaling pathways that orchestrate the behavioral response to stress and determines the resulting level of anxiety.


Asunto(s)
Ansiolíticos , Glucocorticoides , Ratas , Animales , Masculino , Glucocorticoides/farmacología , Glucocorticoides/metabolismo , Corticosterona/metabolismo , Ansiolíticos/farmacología , Mifepristona/farmacología , Sistema Hipotálamo-Hipofisario/metabolismo , Ratas Sprague-Dawley , Receptores de Glucocorticoides/metabolismo , Sistema Hipófiso-Suprarrenal/metabolismo , Ansiedad/tratamiento farmacológico , Ansiedad/metabolismo , Antagonistas de Receptores de Mineralocorticoides/farmacología , Receptores de Mineralocorticoides/metabolismo
3.
Brain Topogr ; 36(5): 644-660, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37382838

RESUMEN

Radiologists routinely analyze hippocampal asymmetries in magnetic resonance (MR) images as a biomarker for neurodegenerative conditions like epilepsy and Alzheimer's Disease. However, current clinical tools rely on either subjective evaluations, basic volume measurements, or disease-specific models that fail to capture more complex differences in normal shape. In this paper, we overcome these limitations by introducing NORHA, a novel NORmal Hippocampal Asymmetry deviation index that uses machine learning novelty detection to objectively quantify it from MR scans. NORHA is based on a One-Class Support Vector Machine model learned from a set of morphological features extracted from automatically segmented hippocampi of healthy subjects. Hence, in test time, the model automatically measures how far a new unseen sample falls with respect to the feature space of normal individuals. This avoids biases produced by standard classification models, which require being trained using diseased cases and therefore learning to characterize changes produced only by the ones. We evaluated our new index in multiple clinical use cases using public and private MRI datasets comprising control individuals and subjects with different levels of dementia or epilepsy. The index reported high values for subjects with unilateral atrophies and remained low for controls or individuals with mild or severe symmetric bilateral changes. It also showed high AUC values for discriminating individuals with hippocampal sclerosis, further emphasizing its ability to characterize unilateral abnormalities. Finally, a positive correlation between NORHA and the functional cognitive test CDR-SB was observed, highlighting its promising application as a biomarker for dementia.


Asunto(s)
Enfermedad de Alzheimer , Disfunción Cognitiva , Humanos , Hipocampo/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Enfermedad de Alzheimer/diagnóstico por imagen , Biomarcadores
4.
Artículo en Inglés | MEDLINE | ID: mdl-37068544

RESUMEN

Serotonin (5-HT) receptors have been implicated in social behavior in vertebrates. Zebrafish (Danio rerio) have been increasingly being used behavioral neuroscience to study the neurobiological correlates of behavior, including sociality. Nonetheless, the role of 5-HT2C receptors in different social functions were not yet studied in this species. Zebrafish were treated with the agonist MK-212 (2 mg/kg) or the antagonist RS-102221 (2 mg/kg) and tested in the social interaction and social novelty tests, conditional approach test, or mirror-induced aggressive displays. MK-212 increased preference for an unknown conspecific in the social investigation test, but also increased preference for the known conspecific in the social novelty test; RS-102221, on the other hand, decreased preference in the social investigation test but increased preference for the novel conspecific in the social novelty test. MK-212 also decreased predator inspection in the conditional approach test. While RS-102221 decreased time in the display zone in the mirror-induced aggressive display test, it increased display duration. Overall, these results demonstrate the complex role of 5-HT2C receptors in different social contexts in zebrafish, revealing a participation in social plasticity in vertebrates.


Asunto(s)
Receptor de Serotonina 5-HT2C , Pez Cebra , Animales , Pez Cebra/fisiología , Serotonina , Conducta Social , Conducta Animal/fisiología
5.
Front Syst Neurosci ; 17: 1103770, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36896148

RESUMEN

Long-term memory is achieved through a consolidation process where structural and molecular changes integrate information into a stable memory. However, environmental conditions constantly change, and organisms must adapt their behavior by updating their memories, providing dynamic flexibility for adaptive responses. Consequently, novel stimulation/experiences can be integrated during memory retrieval; where consolidated memories are updated by a dynamic process after the appearance of a prediction error or by the exposure to new information, generating edited memories. This review will discuss the neurobiological systems involved in memory updating including recognition memory and emotional memories. In this regard, we will review the salient and emotional experiences that promote the gradual shifting from displeasure to pleasure (or vice versa), leading to hedonic or aversive responses, throughout memory updating. Finally, we will discuss evidence regarding memory updating and its potential clinical implication in drug addiction, phobias, and post-traumatic stress disorder.

6.
Sensors (Basel) ; 23(6)2023 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-36991619

RESUMEN

Novelty detection is a statistical method that verifies new or unknown data, determines whether these data are inliers (within the norm) or outliers (outside the norm), and can be used, for example, in developing classification strategies in machine learning systems for industrial applications. To this end, two types of energy that have evolved over time are solar photovoltaic and wind power generation. Some organizations around the world have developed energy quality standards to avoid known electric disturbances; however, their detection is still a challenge. In this work, several techniques for novelty detection are implemented to detect different electric anomalies (disturbances), which are k-nearest neighbors, Gaussian mixture models, one-class support vector machines, self-organizing maps, stacked autoencoders, and isolation forests. These techniques are applied to signals from real power quality environments of renewable energy systems such as solar photovoltaic and wind power generation. The power disturbances that will be analyzed are considered in the standard IEEE-1159, such as sag, oscillatory transient, flicker, and a condition outside the standard attributed to meteorological conditions. The contribution of the work consists of the development of a methodology based on six techniques for novelty detection of power disturbances, under known and unknown conditions, over real signals in the power quality assessment. The merit of the methodology is a set of techniques that allow to obtain the best performance of each one under different conditions, which constitutes an important contribution to the renewable energy systems.

7.
Clin Neurophysiol ; 145: 45-53, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36423366

RESUMEN

OBJECTIVE: Neurophysiological studies exploring involuntary attention have reported that electroencephalographic (EEG) measures can indicate impaired neural processing from initial stages of Parkinson's disease (PD). Since involuntary attention is regulated by right hemisphere networks and PD generally initiates its motor symptomatology unilaterally, whether involuntary attention is impaired depending on the onset side of PD remains unknown. METHODS: We compared the neurophysiological correlates of involuntary attention among a PD group with left-side onset (L-PD), a PD group with right-side onset (R-PD) symptomatology, and a healthy control group (HC). All participants performed an auditory involuntary attention task while a digital EEG was recorded. RESULTS: Our main finding was a reduction both in the P3a amplitude and evoked delta-theta phase alignment in the L-PD group compared to the HC. Further, there was a significant correlation between P3a amplitude and disease duration in the R-PD, but not in the L-PD group. Behaviorally, both clinical groups, and in particular L-PD, showed reduced orientation towards novel stimuli, and no reduction of distraction effects during the experiment. CONCLUSIONS: Our results indicate that involuntary attention is differentially impaired in patients with left side onset of symptoms. Involuntary attention impairment might be present from initial stages of left onset PD and become progressively compromised in patients with right onset PD. SIGNIFICANCE: The onset side of symptomatology should be considered for attentional impairment in PD.


Asunto(s)
Disfunción Cognitiva , Enfermedad de Parkinson , Humanos , Enfermedad de Parkinson/complicaciones , Enfermedad de Parkinson/diagnóstico , Electroencefalografía , Atención/fisiología , Neurofisiología
8.
Foods ; 11(23)2022 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-36496600

RESUMEN

Insects present great potential for the food industry due to their easier rearing conditions and high nutritional value, in comparison with traditional livestock. However, there is a lack of evaluation of the technological status of food products developed with edible insects. Therefore, this study aims to analyze the emergent technological and scientific applications of edible insects in the food industry through a prospective study of patent documents and research articles. Espacenet was used as a research tool, applying the terms Insect, Pupa, Larva, or Nymph and the codes A23L33 and A23V2002. A total of 1139 documents were found-341 were related to the study. Orbit® was used to evaluate technological domains and clusters of concepts. Scopus database research was performed to assess the prevalence of insect research, with the term "edible and insect*". The main insects used were silkworms, bees, beetles, mealworms, crickets, and cicadas. Protein isolates were the predominant technology, as they function as an ingredient in food products or supplements. A diverse application possibility for insects was found due to their nutritional composition. The insect market is expected to increase significantly in the next years, representing an opportunity to develop novel high-quality/sustainable products.

9.
Front Behav Neurosci ; 16: 963739, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36275849

RESUMEN

To survive, animals must recognize relevant stimuli and distinguish them from inconspicuous information. Usually, the properties of the stimuli, such as intensity, duration, frequency, and novelty, among others, determine the salience of the stimulus. However, previously learned experiences also facilitate the perception and processing of information to establish their salience. Here, we propose "perceptual salience" to define how memory mediates the integration of inconspicuous stimuli into a relevant memory trace without apparently altering the recognition of the physical attributes or valence, enabling the detection of stimuli changes in future encounters. The sense of familiarity is essential for successful recognition memory; in general, familiarization allows the transition of labeling a stimulus from the novel (salient) to the familiar (non-salient). The novel object recognition (NOR) and object location recognition (OLRM) memory paradigms represent experimental models of recognition memory that allow us to study the neurobiological mechanisms involved in episodic memory. The catecholaminergic system has been of vital interest due to its role in several aspects of recognition memory. This review will discuss the evidence that indicates changes in dopaminergic activity during exposure to novel objects or places, promoting the consolidation and persistence of memory. We will discuss the relationship between dopaminergic activity and perceptual salience of stimuli enabling learning and consolidation processes necessary for the novel-familiar transition. Finally, we will describe the effect of dopaminergic deregulation observed in some pathologies and its impact on recognition memory.

10.
Neuroimage ; 262: 119516, 2022 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-35931308

RESUMEN

Detection of novel stimuli that violate statistical regularities in the sensory scene is of paramount importance for the survival of biological organisms. Event-related potentials, phasic increases in pupil size, and evoked changes in oscillatory power have been proposed as markers of sensory novelty detection. However, how conscious access to novelty modulates these different brain responses is not well understood. Here, we studied the neural responses to sensory novelty in the auditory modality with and without conscious access. We identified individual thresholds for conscious auditory discrimination and presented to our participants sequences of tones, where the last stimulus could be another standard, a subthreshold target or a suprathreshold target. Participants were instructed to report whether the last tone of each sequence was the same or different from those preceding it. Results indicate that attentional orientation to behaviorally relevant stimuli and overt decision-making mechanisms, indexed by the P3 event-related response and reaction times, best predict whether a novel stimulus will be consciously accessed. Theta power and pupil size do not predict conscious access to novelty, but instead reflect information maintenance and unexpected sensory uncertainty. These results highlight the interplay between bottom-up and top-down mechanisms and how the brain weights neural responses to novelty and uncertainty during perception and goal-directed behavior.


Asunto(s)
Estado de Conciencia , Electroencefalografía , Estimulación Acústica , Atención/fisiología , Percepción Auditiva/fisiología , Estado de Conciencia/fisiología , Electroencefalografía/métodos , Potenciales Evocados/fisiología , Humanos
11.
J Exp Zool B Mol Dev Evol ; 338(5): 314-322, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-34985811

RESUMEN

Spiders constitute more than 49,000 described species distributed all over the world, and all ecological environments. Their order, Araneae, is defined by a set of characteristics with no parallel among their arachnid counterparts (e.g., spinnerets, silk glands, chelicerae that inoculate venom, among others). Changes in developmental pathways often underlie the evolution of morphological synapomorphies, and as such spiders are a promising model to study the role of developmental genes in the origin of evolutionary novelties. With that in mind, we investigated changes in the evolutionary regime of a set of six developmental genes, using spiders as our model. The genes were mainly chosen for their roles in spinneret ontogeny, yet they are pleiotropic, and it is likely that the origins of other unique morphological phenotypes are also linked to changes in their sequences. Our results indicate no great differences in the selective pressures on those genes when comparing spiders to other arachnids, but a few site-specific positive selection evidence were found in the Araneae lineage. These findings lead us to new insights on spider evolution that are to be further tested.


Asunto(s)
Arácnidos , Arañas , Animales , Arácnidos/anatomía & histología , Arácnidos/genética , Genes del Desarrollo , Filogenia , Arañas/anatomía & histología , Arañas/genética
12.
Pensar mov ; 19(2)dic. 2021.
Artículo en Español | SaludCR, LILACS | ID: biblio-1386762

RESUMEN

Resumen Aragón-Vargas, L.F. (2021). Editorial: Originalidad y contexto. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 19(2), 1-4. En este editorial se reflexiona sobre el grado de originalidad que se debe exigir a los manuscritos que se reciben para publicación en las revistas académicas y, más específicamente, en Pensar en Movimiento.


Abstract Aragón-Vargas, L.F. (2021). Editorial: originality and context. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 19(2), 1-4.This editorial presents some reflections on how much originality should be required from those manuscripts submitted for publication in academic journals and, more specifically, in Pensar en Movimiento.


Resumo Aragón-Vargas, L.F. (2021). Editorial: Originalidade e contexto. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 19(2), 1-4. Neste editorial é feita uma reflexão sobre o grau de originalidade exigida dos manuscritos recebidos para publicação nas revistas acadêmicas e, mais especificamente, na Pensar en Movimiento.


Asunto(s)
Investigación , Informe de Investigación
13.
Front Behav Neurosci ; 15: 651263, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34803620

RESUMEN

Maternal separation has been shown to disrupt proper brain development and maturation, having profound consequences on the neuroendocrine systems in charge of the stress response, and has been shown to induce behavioral and cognitive abnormalities. At the behavioral level, maternal separation has been shown to increase offensive play-fighting in juvenile individuals and reduce social interest in adulthood. Since most of the studies that have evaluated the consequences of maternal separation on social behavior have focused on behavioral analysis, there is a need for a further understanding of the neuronal mechanisms underlying the changes in social behavior induced by maternal separation. Therefore, the aim of the present research was to assess the long-term effects of maternal separation on social interaction behavior and to assess the activity of several brain regions involved in the processing of social cues and reward upon social novelty exposure, using c-Fos immunohistochemistry as a marker of neuronal activity. Male Wistar rats were subjected to 4 h maternal separation during the neonatal period, 9:00 h-13:00 h from postnatal day 1 to 21, and exposed to social novelty during adulthood. After social novelty exposure, brains were fixed and coronal sections of the medial amygdala, lateral septum (LS), paraventricular nucleus of the hypothalamus, nucleus accumbens, and medial prefrontal cortex were obtained for c-Fos immunohistochemistry. Maternally separated rats spent less time investigating the novel peer, suggesting that maternal separation reduces social approach motivation. Furthermore, maternal separation reduced the number of c-Fos positive cells of the medial amygdala, paraventricular nucleus of the hypothalamus, LS, nucleus accumbens, and medial prefrontal cortex upon social novelty exposure. These findings suggest that maternal separation can reduce the plastic capacity of several brain nuclei, which constitute a physiological basis for the emergence of behavioral disorders presented later in life reported to be linked to early life adversity.

14.
FEMS Microbiol Ecol ; 97(9)2021 08 17.
Artículo en Inglés | MEDLINE | ID: mdl-34338764

RESUMEN

East African Great Lakes are old and unique natural resources heavily utilized by their bordering countries. In those lakes, ecosystem functioning is dominated by pelagic processes, where microorganisms are key components; however, protistan diversity is barely known. We investigated the community composition of small eukaryotes (<10 µm) in surface waters of four African Lakes (Kivu, Edward, Albert and Victoria) by sequencing the 18S rRNA gene. Moreover, in the meromictic Lake Kivu, two stations were vertically studied. We found high protistan diversity distributed in 779 operational taxonomic units (OTUs), spanning in 11 high-rank lineages, being Alveolata (31%), Opisthokonta (20%) and Stramenopiles (17%) the most represented supergroups. Surface protistan assemblages were associated with conductivity and productivity gradients, whereas depth had a strong effect on protistan community in Kivu, with higher contribution of heterotrophic organisms. Approximately 40% of OTUs had low similarity (<90%) with reported sequences in public databases; these were mostly coming from deep anoxic waters of Kivu, suggesting a high extent of novel diversity. We also detected several taxa so far considered exclusive of marine ecosystems. Our results unveiled a complex and largely undescribed protistan community, in which several lineages have adapted to different niches after crossing the salinity boundary.


Asunto(s)
Eucariontes , Estramenopilos , Biodiversidad , Ecosistema , Eucariontes/genética , Lagos , Filogenia , ARN Ribosómico 18S/genética , Estramenopilos/genética
15.
Neurosci Lett ; 757: 135997, 2021 07 13.
Artículo en Inglés | MEDLINE | ID: mdl-34058293

RESUMEN

Novelty seems to reduce the persistence of aversive memories and to modulate frustration responses, yet much less is known on how this treatment affects memories lacking hedonic or emotional content. The present study analyzed how a 5-min exposure to a novel open field modulated the expression of a spatial recognition memory. Experiment 1 indicated that male Wistar rats trained in a T-maze in which one goal arm is blocked exhibit, when tested 2 h later, preference for the novel arm. This recognition memory was impaired by the muscarinic cholinergic antagonist scopolamine. Postraining, but not pretraining, novelty exposure rescued the cognitive impairment induced by scopolamine (Experiment 2 and 3). Pretraining open field exposure alleviated the lack of memory expression, induced by imposing a 6 h delay between training and testing (Experiment 4). The study shows that a very brief exposure to novelty can improve expression of a spatial, recognition memory, a modulation that - in the case of the pretraining novelty exposure -- emerges even in spite of cholinergic blockade. The present results are consistent with research suggesting that novelty exposure can be an effective, non-pharmacological, treatment to modulate memory expression.


Asunto(s)
Aprendizaje por Laberinto/fisiología , Reconocimiento en Psicología/fisiología , Memoria Espacial/fisiología , Animales , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Modelos Animales , Ratas , Ratas Wistar , Reconocimiento en Psicología/efectos de los fármacos , Escopolamina/administración & dosificación , Memoria Espacial/efectos de los fármacos
16.
Neurobiol Learn Mem ; 181: 107437, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33831511

RESUMEN

The insular cortex (IC) has a crucial role in taste recognition memory, including conditioned taste aversion (CTA). CTA is a learning paradigm in which a novel taste stimulus (CS) is associated with gastric malaise (US), inducing aversion to the CS in future encounters. The role of the IC in CTA memory formation has been extensively studied. However, the functional significance of neurotransmitter release during the presentation of taste stimuli and gastric malaise-inducing agents remains unclear. Using microdialysis in free-moving animals, we evaluated simultaneous changes in glutamate, norepinephrine and dopamine release in response to the presentation of an innate appetitive or aversive gustatory novel stimulus, as well as after i.p. administration of isotonic or hypertonic gastric malaise-inducing solutions. Our results demonstrate that the presentation of novel stimuli, regardless of their innate valence, induces an elevation of norepinephrine and dopamine. Administration of a gastric malaise inducing agent (LiCl) promotes an elevation of glutamate regardless of its concentration. In comparison, norepinephrine release is related to the LiCl concentration and its equimolar NaCl control. Additionally, we evaluated their functional role on short and long-term taste aversion memory. Results indicate that the blockade of noradrenergic ß1,2 receptors in the IC spares CTA acquisition and memory consolidation. In contrast, blockade of dopamine D1/D5 receptors impaired CTA consolidation, whereas the NMDA receptor blockade impedes both acquisition and consolidation of CTA. These results suggest that dopaminergic and noradrenergic release are related to the salience of conditioned taste stimuli. However, only cortical D1/D5 dopaminergic activity, but not the noradrenergic ß1,2 activity, is involved in the acquisition and consolidation of taste memory formation. Additionally, glutamatergic activity signals visceral distress caused by LiCl administration and activates NMDA receptors necessary for the acquisition and consolidation of long-lasting taste aversion memory.


Asunto(s)
Reacción de Prevención/fisiología , Dopamina/metabolismo , Ácido Glutámico/metabolismo , Corteza Insular/metabolismo , Norepinefrina/metabolismo , Reconocimiento en Psicología/fisiología , Animales , Encéfalo/metabolismo , Corteza Cerebral/metabolismo , Inyecciones Intraperitoneales , Interocepción/fisiología , Cloruro de Litio/efectos adversos , Estimulación Física , Ratas , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D5/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Gusto
17.
Anim Cogn ; 24(1): 41-52, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32681199

RESUMEN

Yawning is a stereotypical behavior pattern commonly associated with other behaviors such as grooming, sleepiness, and arousal. Several differences in behavioral and neurochemical characteristics have been described in high-yawning (HY) and low-yawning (LY) sublines from Sprague-Dawley (SD) rats that support they had changes in the neural mechanism between sublines. Differences in behavior and neurochemistry observed in yawning sublines could also overlap in processes needed during taste learning, particularly during conditioned taste aversion (CTA) and its latent inhibition. Therefore, the aim of this study was to analyze taste memory differences, after familiarization to novel or highly sweet stimuli, between yawning sublines and compare them with outbred SD rats. First, we evaluated changes in appetitive response during long-term sugar consumption for 14 days. Then, we evaluated the latent inhibition of CTA strength induced by this long pre-exposure, and we also measured aversive memory extinction rate. The results showed that SD rats and the two sublines developed similar CTA for novel sugar and significantly stronger appetitive memory after long-term sugar exposure. However, after 14 days of sugar exposure, HY and LY sublines were unable to develop latent inhibition of CTA after two acquisition trials and had a slower aversive memory extinction rate than outbreed rats. Thus, the inability of the HY and LY sublines to develop latent inhibition of CTA after long-term sugar exposure could be related to the time/context processes involved in long-term appetitive re-learning, and in the strong inbreeding that characterizes the behavioral traits of these sublines, suggesting that inbreeding affects associative learning, particularly after long-term exposure to sweet stimuli which reflects high familiarization.


Asunto(s)
Gusto , Bostezo , Animales , Reacción de Prevención , Azúcares de la Dieta , Ratas , Ratas Sprague-Dawley , Azúcares
18.
Chem Biol Interact ; 332: 109281, 2020 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-33022268

RESUMEN

The development of fast-acting antidepressants is crucial considering that conventional antidepressants require a long period to elicit therapeutic effects. Creatine, an ergogenic guanidine-like compound, stands out as a candidate to exert fast antidepressant-like responses. The present study investigated whether a single dose of creatine elicits a fast response in mice submitted to the novelty-suppressed feeding (NSF) test, a paradigm that may assess depression-like and anxiety-like behaviors. Ketamine, an NMDA receptor antagonist that has rapid antidepressant effects, and conventional antidepressants were also tested. The involvement of the mTORC1 signaling pathway in the behavioral responses was also investigated. Biochemical analyses included hippocampal BDNF level (ELISA) and total and phospho-mTORC1 (Ser2448), PSD95 and synapsin immunocontent (Western Blotting). Creatine (10 mg/kg, p.o.) or ketamine (1 mg/kg, i.p.) reduced the latency to feed in the NSF test. Conversely, fluoxetine (10 mg/kg, p.o.), imipramine (1 mg/kg, p.o.) or bupropion (10 mg/kg, p.o.) did not alter this parameter. The administration of rapamycin (mTOR inhibitor, 0.2 nmol/site, i.c.v.) abolished the effects of creatine or ketamine in the NSF test. Creatine or ketamine-treated mice presented increased hippocampal BDNF level, an effect abolished by rapamycin. The hippocampal phospho-mTORC1 (Ser2448) immunocontent was increased by creatine, but not by ketamine. However, ketamine, but not creatine, increased PSD95 and synapsin immunocontent. Creatine and ketamine elicit a rapid response in the NSF test by a mechanism dependent on the mTORC1 signaling pathway.


Asunto(s)
Creatina/farmacología , Conducta Alimentaria , Ketamina/farmacología , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Transducción de Señal , Animales , Antidepresivos/farmacología , Conducta Animal/efectos de los fármacos , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Creatina/administración & dosificación , Homólogo 4 de la Proteína Discs Large/metabolismo , Femenino , Hipocampo/metabolismo , Ketamina/administración & dosificación , Ratones , Fosforilación/efectos de los fármacos , Sirolimus/farmacología , Sinapsinas/metabolismo
19.
J Fish Biol ; 97(1): 163-171, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32278332

RESUMEN

Dietary specialization on hard prey items, such as mollusks and crustaceans, is commonly observed in a diverse array of fish species. Many fish consume these types of prey by crushing the shell to consume the soft tissue within, but a few fishes extricate the soft tissue without breaking the shell using a method known as oral shelling. Oral shelling involves pulling a mollusc from its shell and it may be a way to subvert an otherwise insurmountable shell defence. However, the biomechanical requirements and potential adaptations for oral shelling are unknown. Here, we test the hypothesis that a novel nasal protrusion is an adaptation for oral shelling in the durophagous pupfish (Cyprinodon brontotheroides). We first demonstrate oral shelling in this species and then predict that a larger nasal protrusion would allow pupfish to consume larger snails. Durophagous pupfish are found within an endemic radiation of pupfish on San Salvador Island, Bahamas. We took advantage of closely related sympatric species and outgroups to test: (a) whether durophagous pupfish shell and consume more snails than other species, (b) if F1 and F2 durophagous hybrids consume similar amounts of snails as purebred durophagous pupfish, and (c) if nasal protrusion size in parental and hybrid populations increases the maximum size of consumed snails. We found that durophagous pupfish and their hybrids consumed the most snails, but did not find a strong association between nasal protrusion size and maximum snail size consumed within the parental or F2 hybrid population, suggesting that the size of their novel nasal protrusion does not provide a major benefit in oral shelling. Instead, we suggest that the nasal protrusion may increase feeding efficiency, act as a sensory organ, or is a sexually selected trait, and that a strong feeding preference may be most important for oral shelling.


Asunto(s)
Adaptación Fisiológica , Distribución Animal , Conducta Alimentaria/fisiología , Peces Killi/anatomía & histología , Peces Killi/fisiología , Animales , Bahamas , Simpatría
20.
Acta Psychol (Amst) ; 205: 103029, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32169633

RESUMEN

The detection and processing of novelty play a critical role in memory formation. The effect of novelty intervention in memory has been demonstrated with rodents in several lines of research; however, it has not been explored as extensively in humans. In this research, we evaluated the effect of novelty exposure on two types of emotional memory: visual (Study 1) and verbal (Study 2). Eighty healthy volunteers participated in both studies. First, all participants watched a video (session 1); seven days later (session 2), participants in the control group watched the same video and those in the experimental condition were exposed to a novel one. Immediately after exposure, all participants looked at 36 pictures (or listened to 36 words). Soon afterward, a two-task test was administered to evaluate memory (immediate free recall and recognition). A week later (session 3), the two-task test was run again (deferred free recall and recognition). Regarding emotional memory processing, the emotional information was more activating and better remembered than the neutral one, for both visual and verbal information. Regarding the novelty effect, the participants exposed to the novel video had better recall than the control on the deferred measures. Thus, our results provide evidence of the effect of novelty exposure on two different types of emotional memory, with great potentialities in clinical and educational settings.


Asunto(s)
Emociones , Conducta Exploratoria , Memoria a Corto Plazo , Recuerdo Mental , Reconocimiento en Psicología , Estimulación Acústica , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estimulación Luminosa , Proyectos de Investigación , Adulto Joven
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