Correlates of Theta and Gamma Activity during Visuospatial Incidental/Intentional Encoding and Retrieval Indicate Differences in Processing in Young and Elderly Healthy Participants.

Incidental visuospatial learning acquired under incidental conditions is more vulnerable to aging than in the intentional case. The theta and gamma correlates of the coding and retrieval of episodic memory change during aging. Based on the vulnerability of incidental coding to aging, different theta and gamma correlates could occur under the incidental versus intentional coding and retrieval of visuospatial information. Theta and gamma EEG was recorded from the frontotemporal regions, and incidental/intentional visuospatial learning was evaluated in young (25-60 years old) and elderly (60-85 years old) participants. The EEG recorded during encoding and retrieval was compared between incidental low-demand, incidental high-demand, and intentional conditions through an ANCOVA considering the patient's gender, IQ, and years of schooling as covariates. Older adults exhibited worse performances, especially in place-object associations. After the intentional study, older participants showed a further increase in false-positive errors. Higher power at the theta and gamma bands was observed for frontotemporal derivations in older participants for both encoding and retrieval. Under retrieval, only young participants had lower power in terms of errors compared with correct responses. In conclusion, the different patterns of power and coherence support incidental and intentional visuospatial encoding and retrieval in young and elderly individuals. The correlates of power with behavior are sensitive to age and performance.

Septal medial/diagonal band of Broca citalopram infusion reduces place learning efficiency and alters septohippocampal theta learning-related activity in rats.

Increases in power and frequency of hippocampal theta activity have been related to efficient place learning and memory acquisition in hippocampal-dependent tests. The complex medial septum-diagonal band of Broca (MS/DBB) is the pacemaker of hippocampal theta activity, influenced by the ascending synchronizing system, and modulated by serotonergic raphe medial afferents, acting on cholinergic and GABAergic septal neurons. The suppression of hippocampal theta expression and the modulation of hippocampal learning and memory are attributed to serotonin. To simultaneously test these hypotheses, a daily local serotonin increase was induced by citalopram (CIT) infusion (100 µM, 0.88 µl, 0.2 µl/m) 15 min before training in the Morris water maze. The theta activity was recorded in the MS/DBB, dentate gyrus (DG) and CA1 of one group infused with artificial cerebrospinal liquid (ACL) and the other with CIT on Days 1-6 of training. After a probe trial (Day 7) and one resting day, the treatments were reversed (Days 8-11). The CIT MS/DBB infusion in the first 6 training days reduced the efficiency of spatial learning in association with reduced power in the DG, reduced MS/DBB-DG coherence, increased DG-CA1 coherence, and a lack of a negative correlation between MS/DBB power and swam distances. No effect of the CIT occurred once the information was acquired under ACL training. These results support a role of serotonin, in acting on the MS/DBB in the fine tuning of hippocampal learning and memory efficiency through the modulation of learning-related theta activity power and septohipocampal synchronization.

Correlation between intake of omega-3 fatty acids and depressive and anxiety symptoms during pregnancy / Correlación entre la ingesta de ácidos grasos omega-3 y los síntomas de depresión y ansiedad en el embarazo

Abstract: Introduction: Anxiety and depression during pregnancy are disabling disorders associated to complications during the pregnancy, delivery, and postpartum period, with a significant prevalence, between 9 and 20%, hence its importance. Nutritional factors, such as omega-3 fatty acids (ω-3FA) deficiency, have been related with both disorders during pregnancy, especially docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Objective: To evaluate the association between dietary intake of EPA and DHA, and anxiety symptoms (AS) and depressive symptoms (DS) in Mexican pregnant women. Method: The sample consisted of 151 women in the second trimester of pregnancy. Instruments included a Food Frequency Questionnaire, the Trait Anxiety Inventory, and the Edinburgh Postnatal Depression Scale. Results: A daily intake of DHA and EPA of 70 mg/d and 30 mg/d, respectively, was found. The prevalence of AS was 44.4%, and 17.9% for DS. We also found the correlation negatively moderate between dietary intake of DHA and EPA and AS (p = .003, p = .017) and DS (p = .001, p = .020) in the group of women who had a severely insufficient intake of ω-3FA. Discussion and conclusion: The statistical significance shows a negative correlation between variables and the dietary intake of ω-3FA explains in a very small percentage the variability of AS and DS, according to their coefficient of determination. These results suggest the need for an investigation of this relationship through interventional studies.

Resumen: Introducción: La prevalencia de ansiedad y depresión en el embarazo oscilaentre 9 y 20%. Poseen una gran importancia al ser trastornos incapacitantes asociados a complicaciones durante el embarazo, parto y postparto. Factores nutricionales, como la deficiencia de ácidos grasos omega-3 (AGω-3), se han relacionado con ambos trastornos durante el embarazo, especialmente el ácido docosahexaenoico (DHA) y el ácido eicosapentaenoico (EPA). Objetivo: Evaluar la asociación entre la ingesta dietética de EPA y DHA y los síntomas de ansiedad (SA) y depresión (DS) en mujeres embarazadas mexicanas. Método: Se entrevistó a 151 gestantes fueron entrevistadas en el segundo trimestre de embarazo. Los instrumentos de medición utilizados fueron: un Cuestionario de Frecuencia de Consumo de Alimentos, el Inventario de Ansiedad-Rasgo y la Escala de Depresión Postnatal de Edimburgo. Resultados: Se encontró una correlación negativa moderada entre la ingesta de DHA y EPA y los SA (p = .003, p = .017) y SD (p = .001, p = .020) en el grupo de mujeres con ingesta gravemente insuficiente. Se encontró una ingesta dietética diaria de DHA y EPA de 70 mg y 30 mg, respectivamente. La prevalencia de SA fue 44.4% y de SD, 17.9%. Discusión y conclusión: Aunque la significancia estadística mostró una correlación negativa entre variables, de acuerdo con el coeficiente de determinación, la ingesta dietética de AGω-3 explica en un escaso porcentaje la variabilidad de los SA y SD. Estos resultados sugieren la necesidad de investigar dicha relación por medio de estudios de intervención.