Exploring the effects of COVID-19-related traumatic events on the mental health of university students in Brazil: A cross-sectional investigation.

University students are vulnerable to mental health issues during their academic lives. During the COVID-19 pandemic, university students faced mental distress due to lockdowns and the transition to e-learning. However, it is not known whether these students were also affected specifically by COVID-19-related traumatic events.

BDNF-dependent signaling in the olfactory bulb modulates social recognition memory in mice.

An operative olfactory bulb (OB) is critical to social recognition memory (SRM) in rodents, which involves identifying conspecifics. Furthermore, OB also allocates synaptic plasticity events related to olfactory memories in their intricate neural circuit. Here, we asked whether the OB is a target for brain-derived neurotrophic factor (BDNF), a well-known mediator of plasticity and memory.

Social recognition memory differences between mouse strains: On the effects of social isolation, adult neurogenesis, and environmental enrichment.

Remembering conspecifics is paramount for the establishment and maintenance of groups. Here we asked whether the variability in social behavior caused by different breeding strategies affects social recognition memory (SRM). We tested the hypothesis that the inbred Swiss and the outbred C57BL/6 mice behave differently on SRM.

The memory impairment by hypothyroidism in mice is dependent on time-of-day and sex.

Hypothyroidism is an endocrine-metabolic disorder, and as such it compromises a wide range of physiological functions. Memory deficits and, the most recently described, circadian rhythm disruption are among the impairments caused by thyroid dysfunctions. However, although highly likely, there is no evidence connecting these two effects of hypothyroidism.

Strategies adopted by undergraduate teaching assistants in physiology and biophysics education during the COVID-19 pandemic.

The COVID-19 pandemic affected almost all aspects of our lives, including the education sector and the way of teaching and learning. In March 2020, health authorities in Brazil imposed social isolation and the interruption of on-site activities in schools and universities. In this context, the Federal University of Minas Gerais (UFMG), one of the largest universities in Brazil and Latin America, developed an emergency remote learning (ERL) plan that allowed the return of classes in an online format and supported students to obtain access to equipment and internet network.

The effect of context variability on motor learning.

Although the practice schedule and variation in incidental context have been investigated together, it is not clear whether just variation in incidental context can beneficiate motor learning. Therefore, the present study aimed to investigate the effect of context variability on motor learning. We hypothesized the practice in a variable incidental context would enable learners to be more resistant to the effects of the contextual changes when compared to a constant incidental context practice.

On the novel mechanisms for social memory and the emerging role of neurogenesis.

Social memory (SM) is a key element in social cognition and it encompasses the neural representation of conspecifics, an essential information to guide behavior in a social context. Here we evaluate classical and cutting-edge studies on neurobiology of SM, using as a guiding principle behavioral tasks performed in adult rodents. Our review highlights the relevance of the hippocampus, especially the CA2 region, as a neural substrate for SM and suggest that neural ensembles in the olfactory bulb may also encode SM traces.

Early postnatal l-Dopa treatment causes behavioral alterations in female vs. male young adult Swiss mice.

Dopaminergic signaling and neurodevelopment alterations are associated with several neuropsychiatric disorders. Knockout mice for dopamine transporters (DAT) as well as site-specific knockout mice lacking dopaminergic D2 autoreceptors in dopaminergic neurons (DA-D2RKO) display behavioral alterations such as hyperlocomotion and abnormal prepulse inhibition. However, it is possible that dopaminergic imbalances may have different effects during varied neurodevelopmental windows.

Maturation of newborn neurons predicts social memory persistence in mice.

Memory transience is essential to gain cognitive flexibility. Recently, hippocampal neurogenesis is emerging as one of the mechanisms involved in the balance between persistence and forgetting. Social recognition memory (SRM) has its duration prolonged by neurogenesis.

Pro-neurogenic effect of fluoxetine in the olfactory bulb is concomitant to improvements in social memory and depressive-like behavior of socially isolated mice.

Although loneliness is a human experience, it can be estimated in laboratory animals deprived from physical contact with conspecifics. Rodents under social isolation (SI) tend to develop emotional distress and cognitive impairment. However, it is still to be determined whether those conditions present a common neural mechanism.

Molecular Mechanisms Associated with the Benefits of Variable Practice in Motor Learning.

Variable practice promotes a higher level of motor learning than constant practice. The glutamate receptors, -methyl-d-aspartate (NMDA) and alfa-amino-3-hydroxy-5-methyl-4-isoxazolepropionic (AMPA), have been associated with the changes in motor cortex that occur throughout the process of motor learning. Considering that, it is possible that variable practice is more associated with the NMDA and AMPA receptors than constant practice.

Social isolation impairs the persistence of social recognition memory by disturbing the glutamatergic tonus and the olfactory bulb-dorsal hippocampus coupling.

The absence of companion may jeopardize mental health in social animals. Here, we tested the hypothesis that social isolation impairs social recognition memory by altering the excitability and the dialog between the olfactory bulb (OB) and the dorsal hippocampus (dHIP). Adult male Swiss mice were kept grouped (GH) or isolated (SI) for 7 days.

Hippocampus and Prefrontal Cortex Modulation of Contextual Fear Memory Is Dissociated by Inhibiting De Novo Transcription During Late Consolidation.

To uncover the factors that dictate the persistence of a memory, it is critical to determine the molecular basis of consolidation. Here, we submitted male adult C57/BL6 mice to contextual fear conditioning using 1US (US: foot-shock, 0.7 mA, 2 s) or 5US, to generate recent (24 to 48 h) and remote (30 days) memories, respectively.

l-Dopa treatment during perinatal development leads to different behavioral alterations in female vs. male juvenile Swiss mice.

Alterations in dopaminergic signaling and neurodevelopment are associated with many neuropsychiatric disorders, such as attention deficit and hyperactivity disorder (ADHD), autism, and schizophrenia. Imbalances in dopamine levels during prenatal development are associated with behavioral alterations later in life, like hyperactivity and addiction, and it is possible that dopaminergic imbalances may have diverse effects during different neurodevelopmental windows. In this study, we investigate whether an increase in dopamine levels during the perinatal developmental window affects behavior of juvenile male and female Swiss mice.

Fast and slow-twitching muscles are differentially affected by reduced cholinergic transmission in mice deficient for VAChT: A mouse model for congenital myasthenia.

Congenital myasthenic syndromes (CMS) result from reduced cholinergic transmission at neuromuscular junctions (NMJs). While the etiology of CMS varies, the disease is characterized by muscle weakness. To date, it remains unknown if CMS causes long-term and irreversible changes to skeletal muscles.

Inhibiting constitutive neurogenesis compromises long-term social recognition memory.

Although the functional role for newborn neurons in neural circuits is still matter of investigation, there is no doubt that neurogenesis modulates learning and memory in rodents. In general, boosting neurogenesis before learning, using genetic-target tools or drugs, improves hippocampus-dependent memories. However, inhibiting neurogenesis may yield contradictory results depending on the type of memory evaluated.

Estradiol effect on short-term object memory under hypocholinergic condition.

Estrogens positively affect object recognition memory (ORM). However, whether this effect rely on acetylcholine is unknown. Here we investigated if 17β-estradiol (E2) would be able to recover ORM deficits in animals with decreased expression of the Vesicular Acetylcholine Transporter (VAChT KD).

Home-cage odors spatial cues elicit theta phase/gamma amplitude coupling between olfactory bulb and dorsal hippocampus.

The brain oscillations may play a critical role in synchronizing neuronal assemblies in order to establish appropriate sensory-motor integration. In fact, studies have demonstrated phase-amplitude coupling of distinct oscillatory rhythms during cognitive processes. Here we investigated whether olfacto-hippocampal coupling occurs when mice are detecting familiar odors located in a spatially restricted area of a new context.

Reduced Vesicular Acetylcholine Transporter favors antidepressant behaviors and modulates serotonin and dopamine in female mouse brain.

Depression is extremely harmful to modern society. Despite its complex spectrum of symptoms, previous studies have mostly focused on the monaminergic system in search of pharmacological targets. However, other neurotransmitter systems have also been linked to the pathophysiology of depression.

Ovarian Sex Hormones Modulate Compulsive, Affective and Cognitive Functions in A Non-Induced Mouse Model of Obsessive-Compulsive Disorder.

There is currently a lack of understanding of how surgical menopause can influence obsessions, compulsions and associated affective and cognitive functions in female obsessive-compulsive disorder (OCD) patients. Early menopause in women due to surgical removal of ovaries not only causes dramatic hormonal changes, but also may induce affective and cognitive disorders. Here, we tested if surgical removal of ovaries (ovariectomy, OVX), which mimics surgical menopause in humans, would result in exacerbation of compulsive, affective and cognitive behaviors in mice strains that exhibit a spontaneous compulsive-like phenotype.

Vesicular acetylcholine transporter knock down-mice are more susceptible to inflammation, c-Fos expression and sickness behavior induced by lipopolysaccharide.

In addition to the well-known functions as a neurotransmitter, acetylcholine (ACh) can modulate of the immune system. Nonetheless, how endogenous ACh release inflammatory responses is still not clear. To address this question, we took advantage of an animal model with a decreased ACh release due a reduction (knockdown) in vesicular acetylcholine transporter (VAChT) expression (VAChT-KD(HOM)).

Neurogenesis Inhibition Prevents Enriched Environment to Prolong and Strengthen Social Recognition Memory, But Not to Increase BDNF Expression.

Hippocampus-dependent memories, such as social recognition (SRM), are modulated by neurogenesis. However, the precise role of newborn neurons in social memory processing is still unknown. We showed previously that 1 week of enriched environment (EE) is sufficient to increase neurogenesis in the hippocampus (HIP) and the olfactory bulb (OB) of mice.

Angiotensin-(1-7)/Mas axis modulates fear memory and extinction in mice.

Inappropriate defense-alerting reaction to fear is a common feature of neuropsychiatric diseases. Therefore, impairments in brain circuits, as well as in molecular pathways underlying the neurovegetative adjustments to fear may play an essential role on developing neuropsychiatric disorders. Here we tested the hypothesis that interfering with angiotensin-(1-7) [Ang-(1-7)]/Mas receptor axis homeostasis, which appears to be essential to arterial pressure control, would affect fear memory and extinction.

Wistar audiogenic rats display abnormal behavioral traits associated with artificial selection for seizure susceptibility.

Accumulating evidence from different animal models has contributed to the understanding of the bidirectional comorbidity associations between the epileptic condition and behavioral abnormalities. A strain of animals inbred to enhance seizure predisposition to high-intensity sound stimulation, the Wistar audiogenic rat (WAR), underwent several behavioral tests: forced swim test (FST), open-field test (OFT), sucrose preference test (SPT), elevated plus maze (EPM), social preference (SP), marble burying test (MBT), inhibitory avoidance (IAT), and two-way active avoidance (TWAA). The choice of tests aimed to investigate the correlation between underlying circuits believed to be participating in both WAR's innate susceptibility to sound-triggered seizures and the neurobiological substrates associated with test performance.