The Systemic Administration of the Histamine H1 Receptor Antagonist/Inverse Agonist Chlorpheniramine to Pregnant Rats Impairs the Development of Nigro-Striatal Dopaminergic Neurons

The dopaminergic and histaminergic systems are the first to appear during the development of the nervous system. Through the activation of H1 receptors (H1Rs), histamine increases neurogenesis of the cortical deep layers, while reducing the dopaminergic phenotype (cells immunoreactive to tyrosine hydroxylase, TH+) in embryo ventral mesencephalon. Although the function of histamine in neuronal differentiation has been studied, the role of H1Rs in neurogenesis has not been addressed. For this purpose, the H1R antagonist/inverse agonist chlorpheniramine was systemically administered (5 mg/kg, i.p.) to pregnant Wistar rats (gestational days 12–14, E12–14), and control and experimental embryos (E14 and E16) and pups (21-day-old) were evaluated for changes in nigro-striatal development. Western blot and immunohistochemistry determinations showed a significant increase in the dopaminergic markers’ TH and PITX3 in embryos from chlorpheniramine-treated rats at E16. Unexpectedly, 21-day-old pups from the chlorpheniramine-treated group, showed a significant reduction in TH immunoreactivity in the substantia nigra pars compacta and dorsal striatum. Furthermore, striatal dopamine content, evoked [3H]-dopamine release and methamphetamine-stimulated motor activity were significantly lower compared to the control group. These results indicate that H1R blockade at E14–E16 favors the differentiation of dopaminergic neurons, but hampers their migration, leading to a decrease in dopaminergic innervation of the striatum in post-natal life

Las Vallinas (Teverga, Asturias). An Iron Age and roman farmsteas in northern Spain

[ES] Los obstáculos para la prospección a lo largo del paisaje costero del Golfo de Vizcaya, las limitaciones estructurales y materiales de las unidades de asentamiento más pequeñas, y la falta de un control exhaustivo de las alteraciones actuales del terreno, han ocasionado un vacío en el conocimiento sobre la posible presencia de granjas o caseríos en espacios abiertos durante la Edad del Hierro en la región cantábrica. Presentamos por primera vez la existencia de estas granjas, con los hallazgos en Las Vallinas que confirman el uso agrícola del terreno. Al comparar la información de esta alquería con la de castros habitados de la misma época, aportamos una visión más amplia del desarrollo económico de los antiguos Astures desde finales de la Prehistoria hasta el inicio de la ocupación romana. El impacto de la romanización provocó una alteración sin precedentes de las antiguas estructuras sociales y económicas de los Astures en esta zona, dando lugar a una lenta y continua recuperación de la economía rural a partir de finales del siglo I d.C[EN] Obstacles to prospection along the coastal landscape of the Bay of Biscay, structural and material limitations in smaller settlement units, and a lack of comprehensive monitoring of current alterations to the terrain, have all left a dearth of knowledge about the possible presence of open Iron Age farms or hamlets in the Cantabrian region. Presented here for the first time, we demonstrate the existence of these farms with findings verifying agricultural land use at Las Vallinas. In comparing information from this farm with that from inhabited hillforts of the same period, we are also given a wider picture of the economic development of the ancient Astures from the end of prehistory to the beginning of Roman occupation. The impact of Romanization caused an unprecedented upheaval of the old social and economic structures of the Asturs in the area, instigating a slow and steady recovery of a rural economy from the late 1st century AD

Experimental Applications and Factors Involved in Validating Thermal Windows Using Infrared Thermography to Assess the Health and Thermostability of Laboratory Animals

Evaluating laboratory animals’ health and thermostability are fundamental components of all experimental designs. Alterations in either one of these parameters have been shown to trigger physiological changes that can compromise the welfare of the species and the replicability and robustness of the results obtained. Due to the nature and complexity of evaluating and managing the species involved in research protocols, non-invasive tools such as infrared thermography (IRT) have been adopted to quantify these parameters without altering them or inducing stress responses in the animals. IRT technology makes it possible to quantify changes in surface temperatures that are derived from alterations in blood flow that can result from inflammatory, stressful, or pathological processes; changes can be measured in diverse regions, called thermal windows, according to their specific characteristics. The principal body regions that were employed for this purpose in laboratory animals were the orbital zone (regio orbitalis), auricular pavilion (regio auricularis), tail (cauda), and the interscapular area (regio scapularis). However, depending on the species and certain external factors, the sensitivity and specificity of these windows are still subject to controversy due to contradictory results published in the available literature. For these reasons, the objectives of the present review are to discuss the neurophysiological mechanisms involved in vasomotor responses and thermogenesis via BAT in laboratory animals and to evaluate the scientific usefulness of IRT and the thermal windows that are currently used in research involving laboratory animals

Pirexia y cambios en la liberación de GABA y glutamato estriatales durante el déficit y la recuperación funcional motora en un modelo de lesión cerebral traumática grave

Antecedentes: El traumatismo craneoencefálico es una de las principales causas de discapacidad en todo el mundo. Las afecciones después del traumatismo son tanto físicas como neurales, ocasionando respuestas como pirexia y alteración en la neurotransmisión. Objetivo: Evaluar los cambios de temperatura y en la neurotransmisión GABAérgica y glutamatérgica estriatal durante el déficit y la recuperación motora en un modelo de lesión cerebral traumática. Método: En ratas Wistar, se registraron la conducta motora y la temperatura durante 20 días tras una lesión, y con la técnica de microdiálisis cerebral se midieron los niveles de glutamato y de GABA estriatales. Resultados: El traumatismo produce un mayor déficit las primeras 24 horas (p 0.5). Produce un incremento en la temperatura mayormente los primeros 4 días (p 0.05) posterior a la lesión. Se presenta una reducción en los niveles de GABA y de glutamato al día 3, seguida de un restablecimiento durante el tiempo de la recuperación motora. Conclusiones: Los análisis de correlación sugieren que los cambios en la neurotransmisión GABAérgica y glutamatérgica estriatal, y el incremento de la temperatura, después de una lesión cerebral no están asociados con el déficit motor ni con la recuperación funcional motora

Histamine H3 receptor activation reduces the impairment in prepulse inhibition (PPI) of the acoustic startle response and Akt phosphorylation induced by MK-801 (dizocilpine), antagonist at N-Methyl-d-Aspartate (NMDA) receptors

We have investigated the effect of the local activation of histamine H3 receptors (H3Rs) in the rat prefrontal cortex (PFCx) on the impairment of pre-pulse inhibition (PPI) of the startle response induced by the systemic administration of MK-801, antagonist at glutamate N-Methyl-d-Aspartate (NMDA) receptors, and the possible functional interaction between H3Rs and MK-801 on PFCx dopaminergic transmission. Infusion of the H3R agonist RAMH (19.8 ng/1 μl) into the PFCx reduced or prevented the inhibition by MK-801 (0.15 mg/kg, ip) of PPI evoked by different auditory stimulus intensities (5, 10 and 15 dB), and the RAMH effect was blocked by the H3R antagonist/inverse agonist ciproxifan (30.6 ng/1 μl). MK-801 inhibited [3H]-dopamine uptake (−45.4 ± 2.1%) and release (−32.8 ± 2.6%) in PFCx synaptosomes or slices, respectively, and molecular modeling indicated that MK-801 binds to and blocks the rat and human dopamine transporters. However, H3R activation had no effect on the inhibitory action of MK-801 on dopamine uptake and release. In PFCx slices, MK-801 and the activation of H3Rs or dopamine D1 receptors (D1Rs) stimulated ERK-1/2 and Akt phosphorylation. The co-activation of D1Rs and H3Rs prevented ERK-1/2 and Akt phosphorylation, and H3R activation or D1R blockade prevented the effect of MK-801. In ex vivo experiments, the intracortical infusion of the D1R agonist SKF-81297 (37 ng/1 μl) or the H3R agonist RAMH increased Akt phosphorylation, prevented by D1R/H3R co-activation. These results indicate that MK-801 enhances dopaminergic transmission in the PFCx, and that H3R activation counteracts the post-synaptic actions of dopamine

Avaliação de Trichogramma spp. para o controle de Trichoplusia ni Evaluation of Trichogramma spp. for the control of Trichoplusia ni

O objetivo deste trabalho foi avaliar as características biológicas dos parasitoides Trichogramma acacioi, T. atopovirilia, T. marandobai, T. demoraesi, T. exiguum (duas linhagens) e T. pretiosum (seis linhagens), criados em ovos de Trichoplusia ni. O experimento foi conduzido em delineamento inteiramente casualizado, com 15 repetições. As características biológicas avaliadas foram: parasitismo, viabilidade, razão sexual e número de indivíduos por ovo. A percentagem de parasitismo variou entre 7,66 e 53%, com maior valor observado para a linhagem Tspd de Trichogramma pretiosum, e o menor para a linhagem Trecife de T. pretiosum. Não houve diferença significativa dessa espécie quanto à viabilidade, que ficou acima de 85%. A razão sexual variou de 0,75 a 1, e a linhagem Tspd apresentou o menor valor. O número de parasitoides por ovo variou entre 2,39 para T. marandobai (linhagem Tm1) e 1,34 para T. exiguum (linhagem Te1). A espécie que apresentou o melhor desempenho em laboratório foi T. pretiosum (Tspd), com os maiores valores observados na percentagem de parasitismo e na emergência.<br>The objective of this study was to evaluate the biological characteristics of the parasitoids Trichogramma acacioi, T. atopovirilia, T. marandobai, T. demoraesi, T. exiguum (two lines), and T. pretiosum (six lines), reared on eggs of Trichoplusia ni. The experiment was carried out in a completely randomized design, with 15 replicates. The biological characteristics evaluated were: parasitism, viability, sexual ratio and number of individuals per egg. The parasitism percentage varied between 7.66 and 53%, whith highest value observed for Trichogramma pretiosum Tspd line, and the lowest for the T. pretiosum Trecife line. There was no significant difference for the viability, which remained higher than 85%. The sex ratio varied from 0.75 to 1, and Tspd line showed the lowest value. The number of individuals per egg varied between 2.39 for T. marandobai (Tm1 line) and 1.34 for T. exiguum (Te1 line). T. pretiosum (Tspd line) was the species with the best performance in laboratory with the highest values observed in parasitism and in viability