Reconsolidation of appetitive memory and sleep: functional connectomics and plasticity

Introduzione: La dipendenza da cibo \ue8 un disturbo comportamentale caratterizzato da modelli maladattativi di consumo alimentare, in cui alimenti ricchi in zuccheri, sale e/o grassi possono indurre una dipendenza tale da essere paragonata ai disturbi relativi all\u2019abuso di sostanze. Alla base di questo processo vi \ue8 l\u2019associazione tra questi cibi altamente palatabili e la sensazione piacevole e rinforzante indotta dal loro consumo, che pu\uf2 essere codificata in una nuova memoria maladattativa sottostante il disturbo di dipendenza. Infatti, le nuove informazioni che riceviamo quotidianamente dall\u2019esterno vengono processate dal nostro cervello tramite un primo stadio di codifica e un secondo stadio di consolidamento, durante il quale vengono stabilizzate in una nuova memoria e integrate nella rete cerebrale di conoscenze preesistenti. Tuttavia, dopo il suo consolidamento, una memoria pu\uf2 essere destabilizzata e riportata ad uno stato di labilit\ue0 che ne permette la modifica e l\u2019eventuale integrazione con nuove informazioni. Infine, un nuovo processo di stabilizzazione chiamato riconsolidamento \ue8 necessario affinch\ue9 la traccia mnemonica aggiornata sia nuovamente stabilizzata. Da recenti studi, \ue8 noto come il sonno sia rilevante sia per il consolidamento che per il riconsolidamento della memoria. Tuttavia, mentre \ue8 chiaro come il consolidamento che avviene durante il sonno permetta la stabilizzazione a lungo termine delle tracce mnemoniche, non \ue8 ancora stato del tutto chiarito il ruolo del sonno nel processo di riconsolidamento. Scopo: Date queste premesse, e nota l\u2019importanza dell\u2019interazione tra amigdala basolaterale (BLA) e ippocampo nel riconsolidamento delle memorie appetitive, gli obiettivi della presente tesi erano: i) valutare come l\u2019amigdala BLA e ippocampo interagiscono in termini di potenziali locali durante la riattivazione della memoria strumentale effettuata o durante la fase di attivit\ue0 o durante la fase di inattivit\ue0 del ciclo circadiano dei roditori; ii) valutare come il richiamo della memoria effettuato durante la fase attiva o quella inattiva possa influenzare il successivo processo di riconsolidamento, e iii) trovare, in-vivo, un marker di riattivazione della memoria appetitiva. Metodi: Sono stati utilizzati 32 ratti maschi, ceppo Sprague Dawley, a cui sono stati impiantati due elettrodi profondi: uno in BLA e uno in ippocampo, per la registrazione dei potenziali locali. I ratti sono stati sottoposti ad un protocollo comportamentale in gabbia operante di auto-somministrazione di saccarosio, composto da quattro stadi: addestramento (i), in cui i ratti imparavano l\u2019associazione tra la pressione di una leva e l\u2019emissione di un pellet di saccarosio; astinenza (ii), durante la quale i soggetti non venivano esposti al contesto di addestramento; riattivazione o non riattivazione (iii) della memoria strumentale in gabbia operante, svolta o durante la fase di attivit\ue0, o durante la fase di inattivit\ue0; test di ricaduta (iv). I potenziali locali sono stati analizzati per lo stadio (iii) in modo da ottenere la potenza delle oscillazioni theta e gamma per i due elettrodi profondi; tali frequenze sono state scelte in quanto rilevanti per i processi mnemonici. Infatti, il richiamo della memoria \ue8 correlato alla sincronizzazione delle onde theta (4-12 Hz) tra BLA e altre aree cerebrali quali l\u2019area CA1 dell\u2019ippocampo, ed \ue8 inoltre correlato alle basse gamma (30-60 Hz) nell\u2019ippocampo. Infine, l\u2019accoppiamento tra le onde theta e gamma nell\u2019ippocampo \ue8 un noto metodo di comunicazione tra sotto-aree ippocampali nel corso dei processi di memoria. Risultati: I risultati hanno mostrato la presenza di una correlazione inversa tra la potenza delle basse gamma nell\u2019area CA1 ippocampale e il tasso di risposta durante lo stadio di richiamo della memoria nella fase di attivit\ue0, indipendentemente dal fatto che i soggetti stessero o meno premendo la leva. Le basse gamma potrebbero quindi rappresentare un marker di correlazione per il richiamo della memoria appetitiva. Inoltre, la potenza di basse e alte gamma ippocampali aumenta durante le epoche di pressione di leva quando il richiamo della memoria viene effettuato nella fase di inattivit\ue0, suggerendo che le onde gamma potrebbero essere dei marker correlazionali specifici per la componente strumentale del richiamo della memoria effettuato durante la fase di inattivit\ue0. Conclusioni e limitazioni: Per concludere, i risultati hanno mostrato l\u2019importanza delle frequenze basse gamma nel richiamo delle memorie appetitive, tuttavia non hanno mostrato alcuna differenza a livello delle onde theta, n\ue9 a livello della BLA. Di conseguenza, si conclude che il protocollo utilizzato nella presente tesi non ha mostrato una sensibilit\ue0 sufficientemente elevata nell\u2019evidenziare i cambiamenti ipotizzati a livello dei potenziali locali. Lo svolgimento di ulteriori esperimenti che andranno a determinare misure di connettomica quali coerenza e accoppiamento, sia intra- che inter- area, aiuter\ue0 a determinare se e come le due aree comunicano tra di loro.Introduction: Food addiction is a behavioural disorder in which individuals develop maladaptive patterns of food consumption. Particularly, food containing processed sugars, salt, fat etc. can be addictive, and refined food consumption behaviours may meet the criteria for substance use disorders. For these characteristics, food addiction can also be considered a memory disorder. Memories in the brain are processed as follows: new information is encoded and then long-term consolidated through a process allowing its integration into already existing knowledge networks. After a memory has been consolidated, it can be destabilized and brought back to a labile state, requiring a new re-stabilization process called reconsolidation. Memory consolidation is known to require sleep. In fact, sleep allows new memory traces to long-term stabilize. Sleep also seems to influence memory reconsolidation; however, its involvement in this process is not yet clear. Aim: Given these premises, the goals of the project were: to evaluate how basolateral amygdala (BLA) and hippocampus interact in terms of local field potentials (LFPs) when appetitive instrumental memory is retrieved either during active or inactive phase of rats circadian rhythm; to evaluate how retrieving the memory in the activity vs inactivity phase influences following memory reconsolidation; and to find an in vivo electrophysiological marker of appetitive memory retrieval. In fact, it has been shown that BLA and dorsal hippocampus interaction is crucial for appetitive memory reconsolidation. Methods: Thirty-two male Sprague Dawley rats were implanted with in-depth electrodes for LFPs recordings in BLA and dorsal hippocampal CA1 and subject to a behavioural protocol apt to induce appetitive memory retrieval. The behavioural procedure consisted of four stages: training (i), in which animals learned lever pressing \u2013 sucrose reward association; abstinence (ii), during which subjects were not exposed to the training context; memory retrieval or no retrieval (iii): instrumental memory reactivation or no reactivation, performed either during active or inactive phase; and relapse test (iv), during which sucrose-seeking behaviour was analysed. Theta and gamma oscillations powers were analysed during stage (iii). In fact, they are known to be involved in memory processes. Memory retrieval has been shown to correlate with theta (4-12 Hz) synchronization between BLA and other brain areas (such as hippocampal CA1) and with low gamma (30-60 Hz) in hippocampus. Particularly, theta-gamma cross-frequency coupling has been shown to be used as a mean of communication between hippocampal sub-areas during memory processing. Results: Results showed an inverse correlation between hippocampal CA1 low gamma power and reactivation rate of responding (either when rats were lever pressing or not) when reactivation was performed during the active phase. This suggests that low gamma may be a correlational marker of instrumental sucrose memory retrieval, independent of whether rats were lever-pressing or not. Moreover, hippocampal CA1 gamma bands increased when lever pressing during instrumental memory reactivation while in the inactive phase, suggesting that both low and high gamma bands may be correlational markers to actual instrumental responding retrieval during the inactive phase. Conclusions and limitations: In conclusion, results showed that low gamma is relevant in sucrose appetitive memory retrieval. However, no difference was observed in the theta frequency band, nor at the level of BLA. Therefore, the current protocol did not have the sensitivity to detect predicted changes in LFPs. Further experiments would help investigating if and how the two areas interact, by determining connectomics measures such as coherence and coupling within and between areas

BeppoSAX Observations of 1 Jy BL Lacertae Objects. I

We present new BeppoSAX observations of seven BL Lacertae objects selected from the 1 Jy sample plus one additional source. The collected data cover the energy range 0.1 - 10 keV (observer's frame), reaching ~ 50 keV for one source (BL Lac). All sources characterized by a peak in their multifrequency spectra at infrared/optical energies (i.e., of the LBL type) display a relatively flat (alpha_x ~ 0.9) X-ray spectrum, which we interpret as inverse Compton emission. Four objects (2/3 of the LBL) show some evidence for a low-energy steepening which is likely due to the synchrotron tail merging into the inverse Compton component around ~ 1 - 3 keV. If this were generally the case with LBL, it would explain why the 0.1 - 2.4 keV ROSAT spectra of our sources are systematically steeper than the BeppoSAX ones (by ~ 0.5 in alpha_x). The broad-band spectral energy distributions fully confirm this picture and a synchrotron inverse Compton model allows us to derive the physical parameters (intrinsic power, magnetic field, etc.) of our sources. Combining our results with those obtained by BeppoSAX on BL Lacs covering a wide range of synchrotron peak frequencies, we confirm and clarify the dependence of the X-ray spectral index on synchrotron peak frequency originally found in ROSAT data.Comment: 14 pages, 7 figures. Accepted for publication in MNRAS. Postscript file also available at http://icarus.stsci.edu/~padovani/xrayspectra_papers.htm

Exercise Combined with Electrotherapy Enhances Motor Function in an Adolescent with Spinal Muscular Atrophy Type III

Background. Electrotherapy is widely used in physical therapy to increase muscle mass, improve motor function, and assist physical activity in several neurologic conditions. However, concerning Spinal Muscular Atrophy (SMA), limited evidence exists on the role of electrotherapy as an adjunct for improving muscle strength and function. Case Report. An adolescent (13 y.o.) with SMA type III underwent an 18-week strengthening program divided into two stages. During Phase I (weeks: 1-8), a home-based program for quadriceps strengthening through neuromuscular electrical stimulation (NMES) was provided. In Phase II (weeks: 9-18), at-home NMES was combined with functional electrical stimulation (FES) assisting volitional cycling for a broader, systemic conditioning. The treatment improved patient's structural and functional motor outcomes (quadriceps circumference and strength, Tinetti scale, and Hammersmith scale) as well as independence in stair climbing. Clinical Rehabilitation Impact. The purpose of this report is to raise awareness of the potential role of electrotherapy to help improving motor performance in SMA patients and, secondly, to foster further research aimed at assessing the actual contribution this intervention may have as an add-on therapy to existing care

Influence of the brood rearing temperature on honey bee development and susceptibility to intoxication by pesticides

contribution to session IV Test methodolog

Comparison of Communication/Synchronization Models in Parallel Programming on Multi-Core Cluster

Taking into account the increase in use of the multi-core cluster architecture, in this paper we analyze the use of the various communication models (message passing, shared memory, their combination) to efficiently exploit the power of the architecture. Smith-Waterman algorithm, whose parallelization is based on a pipeline scheme due to problem data dependence, is used as test case to determine the similarity degree of two DNA sequences. Finally, future research lines are mentioned, aimed at optimizing the use of memory levels in the architecture.Red de Universidades con Carreras en Informática (RedUNCI

Occipital atrophy signature in prodromal Lewy bodies disease

Introduction: Dementia with Lewy bodies (DLB) is typically characterized by parietal, temporal, and occipital atrophy, but less is known about the newly defined prodromal phases. The objective of this study was to evaluate structural brain alterations in prodromal DLB (p-DLB) as compared to healthy controls (HC) and full-blown dementia (DLB-DEM). Methods: The study included 42 DLB patients (n = 20 p-DLB; n = 22 DLB-DEM) and 27 HC with a standardized neurological assessment and 3-tesla magnetic resonance imaging. Voxel-wise analyses on gray-matter and cortical thickness were implemented to evaluate differences between p-DLB, DLB-DEM, and HC. Results: p-DLB and DLB-DEM exhibited reduced occipital and posterior parieto-temporal volume and thickness, extending from prodromal to dementia stages. Occipital atrophy was more sensitive than insular atrophy in differentiating p-DLB and HC. Occipital atrophy correlated to frontotemporal structural damage increasing from p-DLB to DLB-DEM. Discussion: Occipital and posterior-temporal structural alterations are an early signature of the DLB continuum and correlate with a long-distance pattern of atrophy

Aportes metodológicos para la evaluación de la sustentabilidad en sistemas agrícolas hortícolas en el sureste de la provincia de Buenos Aires

La complejidad de los sistemas productivos puede ser estudiada a través de indicadores. En este trabajo se presenta una metodología tendiente a evaluar la sustentabilidad de sistemas agrícolas hortícolas a nivel de predios en el sureste de la Provincia de Buenos Aires. Para ello se pone a prueba su posible aplicación utilizando seis casos con modelos de producción convencionales y de transición agroecológica. Se indagan indicadores correspondientes a tres dimensiones: la económica, la ecológica y la socio-político-cultural. La aplicación de la metodología permitió caracterizar los predios según sus valores de sustentabilidad, variando la misma entre 3,3 y 2,3, y detectar los aspectos que inciden con mayor intensidad en su condición. Finalmente se sugiere la modificación de algunos indicadores y la incorporación de otros.The complexity of production systems can be studied through indicators. This paper presents a methodology aimed at assessing the sustainability of horticultural cropping systems at farm level in the southeast of the Province of Buenos Aires. For that purpose its possible application models using six cases with conventional production and agro-ecological transition. Economic, ecological and socio-political-cultural: indicators for three dimensions are investigated. The application of the methodology allowed characterizing the properties according to their values of sustainability, varying it between 3.3 and 2.3, and to identify areas that affect most strongly their condition. Finally modifying some indicators and incorporating other suggested.Eje: A1 Sistemas de producción de base agroecológica (Trabajos científicos)Facultad de Ciencias Agrarias y Forestale

Aportes metodológicos para la evaluación de la sustentabilidad en sistemas agrícolas hortícolas en el sureste de la provincia de Buenos Aires

La complejidad de los sistemas productivos puede ser estudiada a través de indicadores. En este trabajo se presenta una metodología tendiente a evaluar la sustentabilidad de sistemas agrícolas hortícolas a nivel de predios en el sureste de la Provincia de Buenos Aires. Para ello se pone a prueba su posible aplicación utilizando seis casos con modelos de producción convencionales y de transición agroecológica. Se indagan indicadores correspondientes a tres dimensiones: la económica, la ecológica y la socio-político-cultural. La aplicación de la metodología permitió caracterizar los predios según sus valores de sustentabilidad, variando la misma entre 3,3 y 2,3, y detectar los aspectos que inciden con mayor intensidad en su condición. Finalmente se sugiere la modificación de algunos indicadores y la incorporación de otros.The complexity of production systems can be studied through indicators. This paper presents a methodology aimed at assessing the sustainability of horticultural cropping systems at farm level in the southeast of the Province of Buenos Aires. For that purpose its possible application models using six cases with conventional production and agro-ecological transition. Economic, ecological and socio-political-cultural: indicators for three dimensions are investigated. The application of the methodology allowed characterizing the properties according to their values of sustainability, varying it between 3.3 and 2.3, and to identify areas that affect most strongly their condition. Finally modifying some indicators and incorporating other suggested.Eje: A1 Sistemas de producción de base agroecológica (Trabajos científicos)Facultad de Ciencias Agrarias y Forestale

Methodological proposal for the sustainability assessment in horticultural systems of the southeast of Buenos Aires

Los indicadores de sustentabilidad aplicados a sistemas productivos agrícolas constituyen herramientas útiles para revertir situaciones críticas. No obstante, no existen metodologías de evaluación de la sustentabilidad de aplicación generalizada. El presente trabajo tiene como objetivo elaborar una propuesta metodológica tendiente a evaluar de manera preliminar la sustentabilidad en sistemas hortícolas del sudeste de la provincia de Buenos Aires y especialmente del periurbano productivo de la ciudad de Mar del Plata (partido de General Pueyrredon). Asumiendo un enfoque técnico-profesional y a partir de la integración de métodos inductivos y deductivos, estudios antecedentes, observaciones directas y entrevistas semiestructuradas a informantes clave, se definieron criterios, indicadores y categorías aplicables al área de estudio. Luego, se realizaron aplicaciones preliminares a dos casos del periurbano marplatense con tipos diferentes de producción: convencional y en transición agroecológica. Se espera con esta propuesta metodológica aportar un instrumento útil para identificar los aspectos críticos en el desarrollo de las actividades hortícolas en el periurbano marplatense y en la región, a fin de revertir situaciones de conflicto ambiental y contribuir con estrategias tendientes a la sustentabilidad.Sustainability indicators applied to agricultural production systems are useful tools to reverse critical situations. However, sustainability assessment methodologies are not widely applicable. The objective of this paper is to elaborate a methodological proposal to preliminarily assess sustainability in horticultural systems of the southeast of the province of Buenos Aires and especially of the productive periurban area of the city of Mar del Plata (General Pueyrredon district). Assuming a technicalprofessional approach and from the integration of inductive and deductive methods, background studies, direct observations and semi-structured interviews with key informants, criteria, indicators and categories applicable to the area of study were defined. Then, preliminary applications were made to two cases of the periurban area of Mar del Plata with different types of production: conventional and in agroecological transition. It is expected with this methodological proposal to provide a useful tool to identify the critical aspects in the development of horticultural activities in the periurban area of Mar del Plata and in the region, in order to revert situations of environmental conflict and contribute with strategies aimed at sustainability.Fil: Zulaica, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Arquitectura, Urbanismo y Diseño. Instituto de Hábitat y Medio Ambiente; ArgentinaFil: Manzoni, Manuel. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; ArgentinaFil: Kemelmajer, Yael. Ministerio de Agricultura Ganaderia y Pesca de la Nacion.; ArgentinaFil: Bisso, Victoria. Ministerio de Agricultura Ganaderia y Pesca de la Nacion.; ArgentinaFil: Padovani, Bárbara. Ministerio de Agricultura Ganaderia y Pesca de la Nacion.; ArgentinaFil: Lempereur, Claire. Provincia de Buenos Aires. Municipalidad de General Pueyrredon; ArgentinaFil: González Cilia, Carolina. Provincia de Buenos Aires. Municipalidad de General Pueyrredon; Argentin

Aportes metodológicos para la evaluación de la sustentabilidad en sistemas agrícolas hortícolas en el sureste de la provincia de Buenos Aires

La complejidad de los sistemas productivos puede ser estudiada a través de indicadores. En este trabajo se presenta una metodología tendiente a evaluar la sustentabilidad de sistemas agrícolas hortícolas a nivel de predios en el sureste de la Provincia de Buenos Aires. Para ello se pone a prueba su posible aplicación utilizando seis casos con modelos de producción convencionales y de transición agroecológica. Se indagan indicadores correspondientes a tres dimensiones: la económica, la ecológica y la socio-político-cultural. La aplicación de la metodología permitió caracterizar los predios según sus valores de sustentabilidad, variando la misma entre 3,3 y 2,3, y detectar los aspectos que inciden con mayor intensidad en su condición. Finalmente se sugiere la modificación de algunos indicadores y la incorporación de otros.The complexity of production systems can be studied through indicators. This paper presents a methodology aimed at assessing the sustainability of horticultural cropping systems at farm level in the southeast of the Province of Buenos Aires. For that purpose its possible application models using six cases with conventional production and agro-ecological transition. Economic, ecological and socio-political-cultural: indicators for three dimensions are investigated. The application of the methodology allowed characterizing the properties according to their values of sustainability, varying it between 3.3 and 2.3, and to identify areas that affect most strongly their condition. Finally modifying some indicators and incorporating other suggested.Eje: A1 Sistemas de producción de base agroecológica (Trabajos científicos)Facultad de Ciencias Agrarias y Forestale