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Effetto delle cure materne e dello stress cronico da separazione materna sulla plasticità neuronale
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Changes on neuronal plasticity in physiological (pregnancy and postpartum) and stressed conditions
No full textNeural plasticity, also known as neuroplasticity is the capability of neurons to changes the structure, function and organization of neurons in response to new experiences. It specifically refers to strengthening or weakening nerve connections or adding new nerve cells based on environmental stimuli. These processes are responsible for physiological changes, learning and the formation of appropriate responses to external event. Neural plasticity is among the most important aspects of the field of modern neuroscience and its study is leading to a better understanding of brain development. In this work the neuroplasticity, in particularly the BDNF and Arc proteins levels, density of dendritic spines and neurogenesis, was studied after different conditions, such as during pregnancy and after delivery or after a prolonged stress, such as maternal separation and social isolation. Our studies have shown an increase in BDNF and Arc proteins levels, density of dendritic spines and neurogenesis during pregnancy and after delivery, in constrast was observed a reduction of BDNF and Arc proteins levels, density of dendritic spines and neurogenesis after a prolonged stress. These results demonstrate that physiological changes or social environments can have significant effects on neuronal plasticity
Maternal separation alters neuronal spine density and neurogenesis in the hippocampus of pups and mother
No full textThe vulnerability of the hippocampus to the negative effects of stress, particularly when experienced early in life, is one of the key translational neuroscience discoveries of the 20th century. Indeed, the quality of perinatal environment and postnatal experience has been shown to predict vulnerability to psychopathologies and cognitive function in the adult. The proposed study aims to improve the knowledge of the adaptive allostatic changes elicited by adverse experiences during lifetime. We focus on adverse experiences that involve mother-infant relationship disruption.
In the present study the mothers was separated for three hours a day from their pups after delivery. The amount of BDNF, Activity–Regulated Cytoskeletal protein (Arc), dendritic spines and neurogenesis was measured in hippocampus of female rats at the weaning and in the hippocampus of pups at 21, 30 and 60 days after birth. All these parameters were markedly decreased in the in hippocampus of mother or pups, respect to the amount found in the mother or pups bred in normal conditions. The motherhood-induced increase the neuronal plasticity as well as the reversal by pups separation suggest a crucial role of these proteins in the regulation of rat maternal care
Regulation of the endocannabinoid receptor CB1 level and synaptic plasticity in prefrontal cortex of food restricted rats
No full textEndocannabinoids (eCB) regulates appetite and feeding behavior acting on different brain areas including the prefrontal cortex (PFC). To further investigate the role of the eCBs in the feeding behavior we evaluated the expression level and localization of the CB1 in neurons of the PFC of rats exposed to food restriction (FR, food availability to a 2-h period daily for 3 weeks) by immunohistochemistry and electrophysiological studies. The amount of CB1 receptor immunostaining was significantly decreased 1h before food presentation, compared to controls; such reduction was still observed during the consumatory phase, but it was no longer apparent 1 h after food removal. Given that in the PFC CB1 are predominantly expressed by a specific subtype of perisomatic GABAergic interneurons, the CCK-containing basket cells, and that their axon target the perisomatic region of pyramidal neurons, we therefore analyzed the changes in CB1 density induced by FR in CCK-positive neurons as well as their co-localization with GAD65 at presynaptic GABAergic terminals. Double immunostaining for CB1 and CCK resulted decreased during the anticipatory phase, 1 h before food presentation, did not change during the consumatory phase, returning to control values 1 h after food removal. Co-localization density of CB1 and GAD65 was very similar to that observed for CB1 and CCK, resulting significantly reduced during the anticipatory and consumatory phase, respectively, but not longer altered 1 h after food removal. We next analyzed the basal properties of GABAA receptor–mediated sIPSCs recorded in voltage clamped (–65 mV) pyramidal neurons in slices of the PFC obtained from FR and control rats.
Moreover we next analyzed the basal properties of GABAA receptor–mediated sIPSCs recorded in voltage-clamped (–65 mV) pyramidal neurons in slices of the PFC obtained from FR and control
rats. These electrophysiological studies have shown that CB1 agonist WIN 55,212-2 reduced the frequency of GABA-induced sIPSCs in PFC pyramidal neurons of control rats, with this effect
being diminished in FR rats during the anticipatory phase before food presentation. Together our data indicate that FR induced changes in the expression level of CB1 receptor in rats may alter the
activity of excitatory synapses suggesting that feeding restriction may exert an effective action strong impact on PFC synaptic plasticity
Effect of maternal care and chronic stress of maternal separation on neuronal plasticity in the rat hippocampus
No full textLiposomes as a carrier for delivery of PGE1: studies in the diabetics rat
No full textThe microangiopathy is the first step of every vascular disease in diabetic patients. Numerous treatment strategies have been developed in an attempt to control diabetics vascular diseases and in particular to speed the healing process, including the use of topical growth factors, living human skin equivalents, hyperbaric oxygen, electrical stimulation. Prostaglandins are cyclic, oxygenated fatty acids that exert different functions in many organs. Recently diabetic patients have been treated with PGE1 delivered by liposome, made with phosphatidylcholine and Poly-L-lysine, containing carnitine, with good clinical results. The ability of the liposome to antagonize the effects of the damage induced by diabetes was tested in diabetic rats. The diabetes in the rats was induced by streptozotocin injection (70 mg/Kg), and then 1μg/kg of liposome was injected ip. twice a week, for three months. The glycemia was checked three times a week and 1 UI insulin retard was administered. Control rats or diabetics rats treated with saline has been used as control. At the third month all the rats were sacrificed, The weight and water consumption were measured. The morphology by histochemistry, apoptosis and VEGF expression levels were studied in gastrocnemius muscle, lungs and kidneys. All these parameters resulted altered in diabetic rats treated with saline. In contrast, diabetics rats treated with PGE1 liposomes, resulted similar to those observed in control animals. The results suggest that such treatment can be considered good terapy to ameliorate some consequences induced by diabetes. All the experiments were performed in the laboratory of Nanobiotechnologies Center. This study was supported by a grant from FASE1
Effetto della separazione materna sulla plasticità dei neuroni ippocampali delle mamme e della prole in età adulta
No full textThree weeks of maternal separation induced a long lasting changes in the palsticity of hippocampal neurons of offspring and mothers
No full textNeural plasticity is the capability of neurons to changes the structure, function and organization of neurons in response to new experiences. It specifically refers to strengthening or weakening nerve connections or adding new nerve cells based on environmental stimuli. These processes are responsible for physiological changes, learning and the formation of appropriate responses to external events. Neural plasticity is among the most important aspects of the field of modern neuroscience and its study is leading to a better understanding of brain development.
In this study the expression levels of BDNF and Arc protein, the density of dendritic spines and the neurogenesis, were studied after a long-lasting stress, due to maternal separation
Neuroplasticity was evaluated in controls (mother and offspring not exposed to maternal separation) and after the stress induced by maternal separation (3h at day from the 3rd to the 21st day after birth). The mothers were sacrificed 21 days after the birth and pups in three different age groups: 21, 30 and 60 days. In the hippocampus of non-stressed we found an increase in the expression levels of the protein BDNF and Arc, in the dendritic spines density and in the neurogenesis, a phenomenon still present at weaning (21 days postpartum). In contrast, opposite effect (decrease) was observed on all the neurogenesis parameters in the mothers separated of their pups for 3 h per day for 20 days. Similarly to the mothers, also in hippocampus of the pups separated from their mothers was present a reduction of BDNF, Arc, dendritic spines density and neurogenesis in all three ages studied (21, 30 and 60). These results demonstrate that stress due to separation in the postnatal period results in adverse effects on neuronal plasticity in the hippocampus of both mothers and offspring
Social isolation induces changes in BDNF, Arc protein and dendritic spine density: reversal by social housing
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