Programación fetal / Fetal programming

El término Origen Temprano de las Enfermedades del Adulto explica la aparición temprana de las condiciones anormales cardiovasculares y metabólicas en la vida adulta, mayor riesgo de morbilidad y muerte asociados a factores ambientales, especialmente nutricionales, que actúan en las primeras etapas de la vida. Estas respuestas programadas dependen de la naturaleza del estímulo o noxa, del tiempo de exposición y del momento de ocurrencia de la noxa, pudiendo un solo genotipo original varios fenotipos y estarían condicionadas por criterios críticos en los cuales se desarrollarían cambios a largo plazo pudiendo ser reversibles o no. La Programación Fetal explica que respuestas adaptativas embrionarias y fetales en un ambiente subóptimo genera consecuencias adversas permanentes. La desnutrición, así como la sobrenutrición fetal aumenta el riesgo de desarrollar alteraciones en el peso y composición corporal fetal, y posteriormente obesidad, síndrome metabólico, incremento en la adiposidad, alteración en el metabolismo de la glucosa y / o insulina, alteración del metabolismo lipídico, alteraciones hepáticas y de las cifras tensionales. La impronta genómica es esencial para el desarrollo y defectos en la misma puede originar alteraciones de la identidad parental transmisibles a las siguientes generaciones. Esta programación fetal puede ser explicada por la epigenética, definida como la serie de alteraciones hereditarias de la expresión genética a través de modificaciones del ADN y las histonas centrales sin cambios en la secuencia de ADN. Estas modificaciones epigenéticas alteran la estructura y condensación de la cromatina, afectando la expresión del genotipo y fenotipo. Este artículo desarrolla los aspectos involucrados en la Programación Fetal y los posibles mecanismos sobre la misma(AU)

The term Early Origin of Adult Diseases explains the early onset of abnormal cardiovascular and metabolic conditions in adult life, increased risk of morbidity and death associated with environmental factors, especially nutritional factors, that act in the early stages of life. These programmed responses depend on the nature of the stimulus or noxa, the time of exposure and the moment of occurrence of the noxa, with a single original genotype being able to have several phenotypes and would be conditioned by critical criteria in which long-term changes could develop, reversibles or not. Fetal Programming explains that embryonic and fetal adaptive responses in a suboptimal environment generate permanent adverse consequences. Fetal malnutrition as overnutrition increases the risk of developing alterations in fetal body weight and composition, and subsequently obesity, metabolic syndrome, increased adiposity, impaired glucose and / or insulin metabolism, impaired lipid metabolism, liver disorders and altered blood pressure. The genomic imprint is essential for development and defects in it can cause alterations of the parental identity and are transmitted to the following generations. This fetal programming can be explained by epigenetics, defined as the series of inherited alterations of genetic expression through modifications of DNA and central histones without changes in the DNA sequence. These epigenetic modifications alter the structure and condensation of chromatin, affecting the expression of the genotype and phenotype. This article develops the aspects involved in Fetal Programming and the possible mechanisms on it(AU)

Agresividad, trastorno antisocial y violencia / Aggressiveness, antisocial upheaval and violence

La violencia interpersonal y colectiva es tan antigua como el hombre; en nuestra generación con la globalización, se observa un aumento de la exportación de la violencia y su incremento en todo el mundo. Los factores de su origen son múltiples: social, familiar, educativo, cultural, económico, biológico, etc. Los sociólogos y los neurocientíficos siguen estudiando intensamente las relaciones entre la conducta humana y la función cerebral. Por otra parte, es indispensable que la sociedad hondureña identifique las formas de violencia que se desarrollan en el entorno doméstico, familiar, laboral y escolar, incluyendo el maltrato a los animales. Esta revisión desarrolla los diferentes aspectos del origen, expresión y resultado de la violencia en la sociedad...

As bases neuroanatômicas do comportamento: histórico e contribuições recentes / Neuroanatomical basis of behavior: history and recent contributions

Tendo em vista as mais recentes contribuições, as áreas corticais límbicas - originalmente denominadas em conjunto de grande lobo límbico -, além dos giros do cíngulo e parahipocampal, são constituídas pelas regiões mais posteriores do córtex fronto-orbitário e pelo córtex insular. Em contraposição ao restante do córtex cerebral, que se projeta sobre os gânglios da base (particularmente sobre as porções mais dorsais e mais extensas do striatum, constituídas fundamentalmente pelo núcleo caudado e pelo putame), as áreas corticais límbicas se caracterizam por se projetarem principalmente sobre o hipotálamo e também sobre a porção mais ventral do striatum (principalmente sobre o núcleo accumbens). Uma vez que todo o striatum se projeta para o globo pálido - e este para o tálamo, que se projeta para o córtex cerebral, constituindo-se, assim, circuitos córtico-subcorticais reentrantes -, tem-se que, enquanto as alças relacionadas com o striatum e o pallidum dorsais são responsáveis por atividades e rotinas motoras, as alças relacionadas com o striatum e o pallidum ventrais caracterizam circuitos córtico-subcorticais reentrantes e segregados que se relacionam particularmente com funções comportamentais. A amígdala estendida (amígdala centromedial, componente dorsal ou estria terminal, componente ventral e núcleo da estria terminal), por sua vez, também recebe aferências de todas as áreas corticais límbicas, é particularmente modulada pelas áreas corticais pré-frontais e, ao invés de se projetar sobre o striatum, projeta-se diretamente sobre o hipotálamo e o tronco encefálico. Ao receber também conexões diretas do tálamo, a amígdala estendida pode ainda desencadear respostas principalmente autonômicas, de forma inespecífica, porém rápida, através da ativação de centros do tronco encefálico. Os sistemas macro-anatômicos fronto-basais, estriatal-palidal ventral e amígdala estendida, em conjunto com o núcleo basal de Meynert e com o sistema septo-banda...

Considering the most recent contributions, the limbic cortical areas, originally known as the greater limbic lobe, besides the cingulated and the parahippocampal gyri also includes the insula and the posterior orbital cortex. In contrast to the nonlimbic cortical areas that project to the basal ganglia (particularly over the dorsal aspects of the striatum, constituted by the caudate nucleus and by the putamen), the limbic cortical areas are characterized by projecting to the hypothalamus and also to the ventral striatum (particularly to the nucleus accumbens). Once all the striatum projects to the globus pallidus which projects to the thalamus and then to the cortex, generating cortical-subcortical reentrant circuits, while the dorsal striatum and pallidum related cortico-subcortical loops are involved with motor activities, the ventral cortical-striatal-pallidal system is particularly related with behavior functions. The extended amygdala (central medial amygdala, stria terminalis or dorsal component, ventral component, and bed nucleus of stria terminalis) receives inputs primarily from the limbic cortical areas, is particularly modulated by the prefrontal cortex, and receives also direct connections from the thalamus that enables the amygdala to generate nonspecific and quick responses through its projections to the hypothalamus and to the brainstem. The ventral striatal-pallidal and the extended amygdala are then two basal forebrain macro-anatomical systems, that together with the basal nucleus of Meynert and with the septal-diagonal band system, constitute the main structures that are particularly connected with the limbic cortical areas, and that altogether project to the hypothalamus and to the brainstem which give rise to the autonomic, endocrine and somatosensory components of the emotional experiences, and that regulate the basic activities of drinking, eating, and related to the sexual behavior.

Enkephalinergic involvement in substantia nigra in the modulation of hypothalamically-induced predatory attack behavior.

The present study was carried out in five cats which did not attack the rats spontaneously. Predatory attack on an anaesthetized rat was elicited by electrical stimulation of lateral hypothalamus at a mean current strength of 650 microA. The attack was accompanied by minimal affective display and culminated in neck biting. Microinfusions of DAME (delta-alanine methionine enkephaline) in 500 ng dose in substantia nigra facilitated the predatory attack and there was a significant reduction in the threshold current strength for affective display as well as somatomotor components. Microinfusions of naloxone, an opioid antagonist in 1.0 microg dose when DAME effect was at its peak reversed the facilitatory effects and the threshold returned to the control levels within 10 minutes of naloxone infusion at the same locus. Microinfusions of naloxone alone in similar dosage completely blocked the predatory attack response as indicated by an increase in the threshold current strength for somatomotor as well as affective display components. The somatomotor were completely inhibited and could not be elicited even when the current strength was increased to 1000 microA. Control injections of saline in similar volumes (0.5 microl) failed to produce any response Microinfusions of naloxone in lower dose (250 ng) failed to produce any blocking effect. These findings indicate that hypothalamically elicited predatory attack is facilitated by enkephalinergic mechanisms operating at the midbrain level.

Electrical and chemical stimulation of the same hypothalamic loci in relation to agressive behaviour in cats: a comparison study.

Chemitrodes which permit electrical and chemical stimulation of the same hypothalamic loci were implanted in anterior hypothalamic and preoptic regions. These sites were stimulated electrically using biphasic square wave pulse (1 ms, 60 Hz) at a current strength ranging from 150-800 microA to evoke an aggressive response. At lower current strength of 150-200 micro A, defence response, a sort of non-specific response can be elicited from these regions. Increasing the current strength to 400 microA led to the recruitment of affective and somatic components and changed the response pattern either to affective attack or flight. The loci producing affective attack response were localized more laterally and ventrally while the loci producing flight response were located in the dorsomedial regions of the hypothalamus. In this response the animal made a goal-directed attempt to escape through an escape route. Increasing the current strength to 500 microA in the dorsomedial regions changed the flight response to violent flight, which involved vigorous running with unsheathed claws and attacking objects if obstructed. Similar increase in current strength at loci producing affective attack only led to a decrease in the latency of response and made the attack more vigorous. Microinfusion of carbachol in graded doses of 2-15 microgram at all these loci produced a profound affective display. At lower doses of 2 and 5 microgram, only some components of affective display like alertness, pupillary dilation and ear flatness were exhibited. Increasing the dose to 10 micrograms and 15 micrograms led to the recruitment of other affective components like piloerection, salivation, hissing and baring of teeth. Microinfusion of carbachol at all loci producing affective attack on electrical stimulation produced a prononced affective display while microinfusion of carbachol at loci producing flight response led to the development of defence posture. At six loci a typical flight response was obtained while violent flight was never exhibited at any of these sites. Microinfusion of atropine (10 microgram in 1.0 microliter saline) at these loci completely blocked the carbachol induced response. Both somatomotor and affective components were completely inhibited. However, the responses obtained on electrical stimulation were not totally blocked following atropine infusion and some of the somatomotor and affective components could be elicited with higher current strength. These studies indicate the involvement of cholinoceptive mechanisms in the elicitation of hypothalamically induced aggresive behaviour. Microinfustion of hexamethonium bromide, a nicotinic blocker in 50 micrograms doses did not affect the aggressive response.