Chronic Toxoplasma gondii infection is associated with decreased working memory performance in women / Infecção crônica por Toxoplasma gondii está associada à diminuição de desempenho da memória de trabalho em mulheres

Abstract Objective The present study sought to investigate changes in mood, inhibitory control, and working memory associated with T. gondii infection in a sample of Brazilian women. Method Twenty-eight female participants were equally distributed into two groups, according to the serology for chronic infection by T. gondii. The participants answered a Sociodemographic questionnaire, the CES-D, and performed Simon and N-Back tasks. Results Infected participants presented less accuracy and longer response time in N-Back tasks. No significant differences were found in the Simon task performance or in the depression levels. Conclusion Our findings suggest that chronic infection by T. gondii may result in impaired working memory and point out the importance of public policies aiming at preventing this infection.

Resumo Objetivo O presente estudo investigou alterações de humor, controle inibitório e memória de trabalho associadas à infecção por T. gondii em uma amostra de mulheres brasileiras. Método Vinte e oito participantes foram distribuídas igualmente em dois grupos de acordo com a sorologia para infecção crônica por T. gondii. As participantes responderam a um questionário sociodemográfico, à CES-D e realizaram as tarefas Simon e N-Back. Resultados As participantes infectadas apresentaram menor acurácia e maior tempo de resposta na tarefa N-Back. Nenhuma diferença significativa foi encontrada na tarefa Simon ou na escala de depressão. Conclusão Nossos achados sugerem que a infecção crônica por T. gondii pode resultar em comprometimento da memória de trabalho, e apontam para a importância de políticas públicas de prevenção dessa infecção.

Prediction of dyskinesia in Parkinson's disease patients using machine learning algorithms.

Dyskinesias are non preventable abnormal involuntary movements that represent the main challenge of the long term treatment of Parkinson's disease (PD) with the gold standard dopamine precursor levodopa. Applying machine learning techniques on the data extracted from the Parkinson's Progression Marker Initiative (PPMI, Michael J. Fox Foundation), this study was aimed to identify PD patients who are at high risk of developing dyskinesias. Data regarding clinical, behavioral and neurological features from 697 PD patients were included in our study. Our results show that the Random Forest was the classifier with the best and most consistent performance, reaching an area under the receiver operating characteristic (ROC) curve of up to 91.8% with only seven features. Information regarding the severity of the symptoms, the semantic verbal fluency, and the levodopa treatment were the most important for the prediction, and were further used to create a Decision Tree, whose rules may guide the pharmacological management of PD symptoms. Our results contribute to the identification of PD patients who are prone to develop dyskinesia, and may be considered in future clinical trials aiming at developing new therapeutic approaches for PD.

5-HT2AR and NMDAR psychedelics induce similar hyper-synchronous states in the rat cognitive-limbic cortex-basal ganglia system.

The profound changes in perception and cognition induced by psychedelic drugs are thought to act on several levels, including increased glutamatergic activity, altered functional connectivity and an aberrant increase in high-frequency oscillations. To bridge these different levels of observation, we have here performed large-scale multi-structure recordings in freely behaving rats treated with 5-HT2AR psychedelics (LSD, DOI) and NMDAR psychedelics (ketamine, PCP). While interneurons and principal cells showed disparate firing rate modulations for the two classes of psychedelics, the local field potentials revealed a shared pattern of synchronized high-frequency oscillations in the ventral striatum and several cortical areas. Remarkably, the phase differences between structures were close to zero, corresponding to <1 ms delays. Likely, this hypersynchrony has major effects on the integration of information across neuronal systems and we propose that it is a key contributor to changes in perception and cognition during psychedelic drug use. Potentially, similar mechanisms could induce hallucinations and delusions in psychotic disorders and would constitute promising targets for new antipsychotic treatments.

Systems-level analysis of local field potentials reveals differential effects of lysergic acid diethylamide and ketamine on neuronal activity and functional connectivity.

Psychedelic substances have in recent years attracted considerable interest as potential treatments for several psychiatric conditions, including depression, anxiety, and addiction. Imaging studies in humans point to a number of possible mechanisms underlying the acute effects of psychedelics, including changes in neuronal firing rates and excitability as well as alterations in functional connectivity between various brain nodes. In addition, animal studies using invasive recordings, have suggested synchronous high-frequency oscillations involving several brain regions as another key feature of the psychedelic brain state. To better understand how the imaging data might be related to high-resolution electrophysiological measurements, we have here analyzed the aperiodic part of the local field potential (LFP) in rodents treated with a classic psychedelic (LSD) or a dissociative anesthetic (ketamine). In addition, functional connectivity, as quantified by mutual information measures in the LFP time series, has been assessed with in and between different structures. Our data suggest that the altered brain states of LSD and ketamine are caused by different underlying mechanisms, where LFP power shifts indicate increased neuronal activity but reduced connectivity following ketamine, while LSD also leads to reduced connectivity but without an accompanying change in LFP broadband power.

Levodopa-induced dyskinesia is preceded by increased levels of anxiety and motor impairment in Parkinson's disease patients.

Introduction: Dopamine replacement therapy with levodopa is the gold standard treatment of Parkinson's disease (PD); however long-term levodopa use is associated with abnormal involuntary movements known as levodopa-induced dyskinesia (LID) in most patients. LID is not preventable and represents the major limitation of PD treatment.Objective: This study was aimed to find clinical and behavioral features that could be used to identify, years in advance, PD patients that are at high risk of developing LID in the future. Method: Data from PD patients enrolled in The Parkinson's progression markers initiative (PPMI, Michael J. Fox Foundation) that developed dyskinesia during their participation in the study were compared with those who did not, and with healthy controls.Result: LID was preceded byhigher levels of trait anxiety and increased motor impairment in PD patients. Additionally, younger age at PD diagnosis, earlier need for dopaminergic therapy and higher initial levodopa dose, were associated with future development of dyskinesia.Conclusion: These findings suggest that easily detectable clinical and behavioral alterations may help to identify PD patients that are more susceptible to develop LID.

ß-carboline-independent antidepressant-like effect of the standardized extract of the barks of Mimosa tenuiflora (Willd) Poir. occurs via 5-HT2A/2C receptors in mice.

BACKGROUND: Depression is a psychiatric disorder with limited therapy options. Psychedelics are new antidepressant candidates, being the ayahuasca one of the most promising ones. A synergistic combination of N,N-dimethyltryptamine (DMT) and ß-carbolines allows ayahuasca antidepressant properties. Another psychedelic and DMT-containing beverage is the jurema wine used religiously by indigenous people from Northeastern Brazil. AIMS: To evaluate the antidepressant-like effect of standardized extract of Mimosa tenuiflora (SEMT), associated or not with harmine (ß-carboline), in behavioral models of depression. METHODS: The SEMT was submitted to (+) ESI-IT-LC/MS analysis for DMT quantification. To assess the antidepressant-like effect of SEMT, the open field (OFT), tail suspension (TST), and forced swim (FST) tests were performed. To verify the participation of serotonergic systems, the 5-hydroxytryptophan (5-HTP)-induced head twitch test was performed. RESULTS: The content of DMT found in SEMT was 24.74 ± 0.8 mg/g. Yuremamine was also identified. SEMT presented an antidepressant-like effect in mice submitted to the TST and FST, independent from harmine, with no significant alterations on the OFT. The sub-dose interaction between SEMT and ketamine also produced an anti-immobility effect in the TST, with no changes in the OFT. SEMT potentiated the head twitch behavior induced by 5-HTP and ketanserin prevented its antidepressant-like effect in the TST (p < 0.05). CONCLUSIONS: SEMT presented a harmine-independent antidepressant-like effect in mice submitted to the TST and FST. This effect occurs possibly via activation of serotonergic systems, particularly the 5-HT2A/2C receptors.

Effects of Transcranial Direct Current Stimulation on Memory of Elderly People with Mild Cognitive Impairment or Alzheimer's Disease: A Systematic Review.

Background: Transcranial direct current stimulation (tDCS) is one of the most studied non-invasive neuromodulation techniques, presenting itself as a promising technique for several pathologies, such as cognitive decline. Objectives: The aim of this study was to conduct a systematic review of the effects of tDCS on the memory of elderly people with mild cognitive impairment or Alzheimer's disease, in order to describe the main protocols used, and to investigate the therapeutic effectiveness of this technique. Data Sources and Methods: 869 studies reporting controlled clinical trials were found in the databases PubMed, Web of Science, Lilacs, PsycArticles and Scielo, from which 13 met the expected requirements and were included in the final analysis. Results: There was a great variability in the stimulation protocols used in the studies; and methodological weaknesses were observed, such as absence of sample size calculation, and of information on effect sizes. Positive effects of tDCS were observed only in five studies, and the combination of stimulation and cognitive training did not seem to potentiate the effects of tDCS. Conclusion: Although tDCS can be considered a technique with important therapeutic potential, more studies are needed to understand the acute effects of tDCS on memory of elderly people and the durability of these effects over time. Registration: PROSPERO (CRD-42020200573).

Mindfulness and relaxation: the effects of a program with university hospital workers / Mindfulness e relaxamento: efeitos de um programa com trabalhadores de um hospital universitário

Our study compared the effects of mindfulness and relaxation interventions on stress, quality of life, resilience, and mindfulness levels. A total of 29 workers, recruited at a university hospital in the northeastern region of Brazil and distributed in two groups: Mindfulness (89.5% female, age mean 37.5 ± 6.23 years old); and Relaxation (90.0% female, age mean 34.2 ± 8.66). After eight weeks of daily mindfulness or relaxation practices, both groups significantly reduced the perceived stress and stress at work, and increased their mindfulness and resilience levels, as well as the physical and psychological quality of life domains. Our results suggest that both interventions may be effective in the organizational environment, assisting in health promotion and increasing the ability of individuals to recover from an adversity (resilience).

Este estudo comparou os efeitos de intervenções baseadas em mindfulness e em relaxamento sobre níveis de estresse, qualidade de vida e resiliência. Participaram do estudo 29 trabalhadores de um hospital universitário do nordeste do Brasil, distribuídos em dois grupos: Mindfulness (89,5% mulheres, média de idade 37,5 ± 6,23); e Relaxamento (90,0% mulheres, média de idade 34,2 ± 8,66). Após oito semanas de práticas diárias dessas internveções, ambos os grupos reduziram significativamente o estresse percebido e aumentaram os níveis de mindfulness, de resiliência e os domínios físico e psicológico da qualidade de vida. Nossos resultados sugerem que elas podem ser eficazes no ambiente organizacional, auxiliando na promoção da saúde e aumentando a capacidade dos indivíduos de se recuperarem da adversidade (resiliência).

Cortical and striatal circuits together encode transitions in natural behavior.

In natural behavior, we fluidly change from one type of activity to another in a sequence of motor actions. Corticostriatal circuits are thought to have a particularly important role in the construction of action sequences, but neuronal coding of a sequential behavior consisting of different motor programs has not been investigated at the circuit level in corticostriatal networks, making the exact nature of this involvement elusive. Here, we show, by analyzing spontaneous self-grooming in rats, that neuronal modulation in motor cortex and dorsal striatum is strongly related to transitions between behaviors. Our data suggest that longer action sequences in rodent grooming behavior emerge from stepwise control of individual behavioral transitions, where future actions are encoded differently depending on current motor state. This state-dependent motor coding was found to differentiate between rare behavioral transitions and as opposed to more habitual sequencing of actions.

Oscillations in cortico-basal ganglia circuits: implications for Parkinson's disease and other neurologic and psychiatric conditions.

Cortico-basal ganglia circuits are thought to play a crucial role in the selection and control of motor behaviors and have also been implicated in the processing of motivational content and in higher cognitive functions. During the last two decades, electrophysiological recordings in basal ganglia circuits have shown that several disease conditions are associated with specific changes in the temporal patterns of neuronal activity. In particular, synchronized oscillations have been a frequent finding suggesting that excessive synchronization of neuronal activity may be a pathophysiological mechanism involved in a wide range of neurologic and psychiatric conditions. We here review the experimental support for this hypothesis primarily in relation to Parkinson's disease but also in relation to dystonia, essential tremor, epilepsy, and psychosis/schizophrenia.

Neurophysiological effects in cortico-basal ganglia-thalamic circuits of antidyskinetic treatment with 5-HT1A receptor biased agonists.

Recently, the biased and highly selective 5-HT1A agonists, NLX-112, F13714 and F15599, have been shown to alleviate dyskinesia in rodent and primate models of Parkinson's disease, while marginally interfering with antiparkinsonian effects of levodopa. To provide more detailed information on the processes underlying the alleviation of dyskinesia, we have here investigated changes in the spectral contents of local field potentials in cortico-basal ganglia-thalamic circuits following treatment with this novel group of 5-HT1A agonists or the prototypical agonist, 8-OH-DPAT. Dyskinetic symptoms were consistently associated with 80 Hz oscillations, which were efficaciously suppressed by all 5-HT1A agonists and reappeared upon co-administration of the antagonist, WAY100635. At the same time, the peak-frequency of fast 130 Hz gamma oscillations and their cross-frequency coupling to low-frequency delta oscillations were modified to a different extent by each of the 5-HT1A agonists. These findings suggest that the common antidyskinetic effects of these drugs may be chiefly attributable to a reversal of the brain state characterized by 80 Hz gamma oscillations, whereas the differential effects on fast gamma oscillations may reflect differences in pharmacological properties that might be of potential relevance for non-motor symptoms.

Changes in neuronal activity of cortico-basal ganglia-thalamic networks induced by acute dopaminergic manipulations in rats.

The basal ganglia are thought to be particularly sensitive to changes in dopaminergic tone, and the realization that reduced dopaminergic signaling causes pronounced motor dysfunction is the rationale behind dopamine replacement therapy in Parkinson's disease. It has, however, proven difficult to identify which neurophysiological changes that ultimately lead to motor dysfunctions. To clarify this, we have here recorded neuronal activity throughout the cortico-basal ganglia-thalamic circuits in freely behaving rats during periods of immobility following acute dopaminergic manipulations, involving both vesicular dopamine depletion and antagonism of D1 and D2 type dopamine receptors. Synchronized and rhythmic activities were detected in the form of betaband oscillations in local field potentials and as cortical entrainment of action potentials in several basal ganglia structures. Analyses of the temporal development of synchronized oscillations revealed a spread from cortex to gradually also include deeper structures. In addition, firing rate changes involving neurons in all parts of the network were observed. These changes were typically relatively balanced within each structure, resulting in negligible net rate changes. Animals treated with D1 receptor antagonist showed a rapid onset of hypokinesia that preceded most of the neurophysiological changes, with the exception of these balanced rate changes. Parallel rate changes in functionally coupled ensembles of neurons in different structures may therefore be the first step in a cascade of neurophysiological changes underlying motor symptoms in the parkinsonian state. We suggest that balanced rate changes in distributed networks are possible mechanism of disease that should be further investigated in conditions involving dopaminergic dysfunction.

Motor deficits and beta oscillations are dissociable in an alpha-synuclein model of Parkinson's disease.

Parkinson's disease (PD) is a neurodegenerative disorder characterised by progressive motor symptoms resulting from chronic loss of dopaminergic neurons in the nigrostriatal pathway. The over expression of the protein alpha-synuclein in the substantia nigra has been used to induce progressive dopaminergic neuronal loss and to reproduce key histopathological and temporal features of PD in animal models. However, the neurophysiological aspects of the alpha-synuclein PD model have been poorly characterised. Hereby, we performed chronic in vivo electrophysiological recordings in the corticostriatal circuit of rats injected with viral vector to over express alpha-synuclein in the right substantia nigra. Our model, previously shown to exhibit mild motor deficits, presented moderate dopaminergic cell loss but did not present prominent local field potential oscillations in the beta frequency range (11-30 Hz), considered a hallmark of PD, during the 9 weeks after onset of alpha-synuclein over expression. Spinal cord stimulation, a potential PD symptomatic therapy, was applied regularly from sixth to ninth week after alpha-synuclein over expression onset and had an inhibitory effect on the firing rate of corticostriatal neurons in both control and alpha-synuclein hemispheres. Dopamine synthesis inhibition at the end of the experiment resulted in severe parkinsonian symptoms such as akinesia and increased beta and high-frequency (>90 Hz) oscillations. These results suggest that the alpha-synuclein PD model with moderate level of dopaminergic depletion does not reproduce the prominent corticostriatal beta oscillatory activity associated to parkinsonian conditions.

Spinal cord stimulation improves forelimb use in an alpha-synuclein animal model of Parkinson's disease.

Neuromodulation by spinal cord stimulation has been proposed as a symptomatic treatment for Parkinson's disease. We tested the chronic effects of spinal cord stimulation in a progressive model of Parkinson's based on overexpression of alpha-synuclein in the substantia nigra. Adult Sprague Dawley rats received unilateral injections of adeno-associated virus serotype 6 (AAV6) in the substantia nigra to express alpha-synuclein. Locomotion and forepaw use of the rats were evaluated during the next 10 weeks. Starting on week 6, a group of AAV6-injected rats received spinal cord stimulation once a week. At the end of the experiment, tyrosine hydroxylase and alpha-synuclein immunostaining were performed. Rats with unilateral alpha-synuclein expression showed a significant decrease in the use of the contralateral forepaw, which was mildly but significantly reverted by spinal cord stimulation applied once a week from the 6th to the 10th week after the AAV6 injection. Long-term spinal cord stimulation proved to be effective to suppress or delay motor symptoms in a sustained and progressive model of Parkinson's and might become an alternative, less invasive neuromodulation option to treat this disease.

Systems-level neurophysiological state characteristics for drug evaluation in an animal model of levodopa-induced dyskinesia.

Disorders affecting the central nervous system have proven particularly hard to treat, and disappointingly few novel therapies have reached the clinics in recent decades. A better understanding of the physiological processes in the brain underlying various symptoms could therefore greatly improve the rate of progress in this field. We here show how systems-level descriptions of different brain states reliably can be obtained through a newly developed method based on large-scale recordings in distributed neural networks encompassing several different brain structures. Using this technology, we characterize the neurophysiological states associated with parkinsonism and levodopa-induced dyskinesia in a rodent model of Parkinson's disease together with pharmacological interventions aimed at reducing dyskinetic symptoms. Our results show that the obtained electrophysiological data add significant information to conventional behavioral evaluations and hereby elucidate the underlying effects of treatments in greater detail. Taken together, these results potentially open up for studies of neurophysiological mechanisms underlying symptoms in a wide range of neurological and psychiatric conditions that until now have been very hard to investigate in animal models of disease.

Attention, locomotor activity and developmental milestones in rats prenatally exposed to ethanol.

RATIONALE: Decline of attentional performance as a function of time engaged on a task and hyperactivity are features shared by children and adults with fetal alcohol syndrome or attentional deficit and hyperactivity disorders. OBJECTIVE: To investigate the effects of prenatal exposure to two doses of ethanol on developmental milestones, locomotor activity and attention. METHODS: Wistar rats born from dams exposed to one of four maternal treatments during pregnancy were used: A35 - liquid diet with 35% ethanol-derived calories; A10 - liquid diet with 10% ethanol-derived calories; control - ethanol-free liquid diet; chow - laboratory chow and water. RESULTS: A35 performed worse in grip strength than control and chow (postnatal day - 14, p<0.05) but not in negative geotaxis (postnatal days 7-10); A35 also showed more locomotor activity than control and A10 (p<0.05). Regarding attention, acquisition of the five choice reaction time task was similar between groups, but, the percentage of omission errors from A35 group was greater than other groups at baseline parameters, at shorter (2s) and longer (7s) inter-trial intervals and at a shorter stimulus duration (0.5s) (p<0.05). The percentage of omissions was larger in A35 as the blocks progressed in sessions with either longer or shorter inter-trial intervals (group×block p<0.05). Animals from A10 group did not show any impairment in the tasks performed. CONCLUSIONS: Our study demonstrates that as well as developmental impairments, prenatal ethanol can produce deficits associated with an increase in attentional demand in rodents, analogous to those observed in fetal alcohol syndrome and attentional deficit and hyperactivity disorders.

Parenthood in the context of maternal depression at the end of the infant's first year of life / Parentalidade no contexto da depressão materna no final do primeiro ano de vida do bebê

The present study investigated parenthood in the context of maternal depression, at the end of the first year of the infant's life. The participants of the study were 22 families, from different socioeconomic levels, divided into two groups, one with mothers who did not present indicators of depression (n=12) and another group with mothers who did (n=10), based on the Beck Depression Inventory. All the mothers were primiparous and lived with the child's father, the babies were approximately 12 months of age. The mothers and fathers participated in an interview that investigated several parenting aspects. Qualitative content analysis of the interviews indicated that, compared to the group without depression, the depressed mothers, as well as their husbands, reported more difficulties regarding division tasks, financial concerns, and divergences and conflicts in child care. These results corroborate other studies which emphasized that the presence of indicators of maternal depression can cause difficulties in parenting...

O presente estudo investigou a parentalidade no contexto de depressão materna, no final do primeiro ano de vida do bebê. Participaram do estudo 22 famílias de diferentes níveis socioeconômicos, distribuídas em dois grupos: um cujas mães (n=10) apresentavam indicadores de depressão, e outro cujas mães (n=12) não os apresentavam, segundo o Inventário Beck de Depressão. Todas eram primíparas e viviam com o pai do bebê, que tinha em torno de 12 meses de idade. Mães e pais responderam a uma entrevista que investigou diversos aspectos da parentalidade. Análise de conteúdo qualitativa das entrevistas indicou que, quando comparadas ao grupo sem depressão, tanto as mães deprimidas como seus maridos relataram maiores dificuldades quanto à divisão de tarefas, preocupações financeiras e divergências e conflitos nos cuidados do filho. Esses resultados corroboram outros estudos que destacaram que a presença de indicadores de depressão materna pode trazer dificuldades para a parentalidade...

Parenthood in the context of maternal depression at the end of the infant's first year of life / Parentalidade no contexto da depressão materna no final do primeiro ano de vida do bebê

The present study investigated parenthood in the context of maternal depression, at the end of the first year of the infant's life. The participants of the study were 22 families, from different socioeconomic levels, divided into two groups, one with mothers who did not present indicators of depression (n=12) and another group with mothers who did (n=10), based on the Beck Depression Inventory. All the mothers were primiparous and lived with the child's father, the babies were approximately 12 months of age. The mothers and fathers participated in an interview that investigated several parenting aspects. Qualitative content analysis of the interviews indicated that, compared to the group without depression, the depressed mothers, as well as their husbands, reported more difficulties regarding division tasks, financial concerns, and divergences and conflicts in child care. These results corroborate other studies which emphasized that the presence of indicators of maternal depression can cause difficulties in parenting.(AU)

O presente estudo investigou a parentalidade no contexto de depressão materna, no final do primeiro ano de vida do bebê. Participaram do estudo 22 famílias de diferentes níveis socioeconômicos, distribuídas em dois grupos: um cujas mães (n=10) apresentavam indicadores de depressão, e outro cujas mães (n=12) não os apresentavam, segundo o Inventário Beck de Depressão. Todas eram primíparas e viviam com o pai do bebê, que tinha em torno de 12 meses de idade. Mães e pais responderam a uma entrevista que investigou diversos aspectos da parentalidade. Análise de conteúdo qualitativa das entrevistas indicou que, quando comparadas ao grupo sem depressão, tanto as mães deprimidas como seus maridos relataram maiores dificuldades quanto à divisão de tarefas, preocupações financeiras e divergências e conflitos nos cuidados do filho. Esses resultados corroboram outros estudos que destacaram que a presença de indicadores de depressão materna pode trazer dificuldades para a parentalidade.(AU)

Prenatal alcohol exposure did not affect impulsivity in rats that performed delay or probability discounting tasks

Individuals who fall under the spectrum of the Fetal Alcohol Syndrome have a higher prevalence of several cognitive disturbances, including a greater probability of being diagnosed with attention-deficit hyperactivity disorder (ADHD). Some of these effects, such as hyperactivity and attentional impairments, are already well established in the literature. The assessment of impulsive choice, however, has received little attention in human and animal studies. In the present study, we attempted to investigate the effects of prenatal ethanol exposure on two tasks related to impulsive choice that have never been studied in this condition: delay and probability discounting. METHOD: Rats prenatally exposed to ethanol (liquid diets with 0 percent, 10 percent, or 35 percent ethanol-derived calories [EDC] or laboratory chow) were trained to respond for food in either delay (n = 21) or probability (n = 48) discounting tasks performed in computer-controlled operant conditioning chambers. RESULTS: Prenatal treatment failed to differentiate the rates at which the rats chose the larger reinforcer associated with delay - in a task in which 35 percent EDC was not tested - or risk, although the results suggest that further tests are warranted.

Prenatal alcohol exposure did not affect impulsivity in rats that performed delay or probability discounting tasks

Individuals who fall under the spectrum of the Fetal Alcohol Syndrome have a higher prevalence of several cognitive disturbances, including a greater probability of being diagnosed with attention-deficit hyperactivity disorder (ADHD). Some of these effects, such as hyperactivity and attentional impairments, are already well established in the literature. The assessment of impulsive choice, however, has received little attention in human and animal studies. In the present study, we attempted to investigate the effects of prenatal ethanol exposure on two tasks related to impulsive choice that have never been studied in this condition: delay and probability discounting. METHOD: Rats prenatally exposed to ethanol (liquid diets with 0 percent, 10 percent, or 35 percent ethanol-derived calories [EDC] or laboratory chow) were trained to respond for food in either delay (n = 21) or probability (n = 48) discounting tasks performed in computer-controlled operant conditioning chambers. RESULTS: Prenatal treatment failed to differentiate the rates at which the rats chose the larger reinforcer associated with delay - in a task in which 35 percent EDC was not tested - or risk, although the results suggest that further tests are warranted.(AU)