Search results for "Amygdala"
showing 9 items of 169 documents
Effects of Chronic Social Defeat Stress on Behavior and Dopamine Receptors in Adolescent Mice With 6-Hydroxydopamine Lesions of the Medial Prefrontal…
2021
Background: Social stress factors in schizophrenia have long-term effects, but will only induce symptoms in a portion of individuals, even if exposed to identical stress.Methods: In the current experiment, we examined mice with 6-hydroxydopamine (6-OHDA)-induced medial prefrontal cortical (mPFC) injury to select for members of a “stress-susceptible group,” and observed the changes in their behavior and the expression of D1 and D2 dopamine receptors in the amygdala and hippocampus.Results: We observed that after chronic social defeat stress, 72.6% of the 6-OHDA lesioned mice exhibited stress response to aggressors, compared to 52.3% of the blank control group. Both the 6-OHDA lesion + social…
Amygdala response to anticipation of dyspnea is modulated by 5-HTTLPRgenotype
2015
Dyspnea anticipation and perception varies largely between individuals. To investigate whether genetic factors related to negative affect such as the 5-HTTLPR polymorphism impact this variability, we investigated healthy, 5-HTTLPR stratified volunteers using resistive load induced dyspnea together with fMRI. Alternating blocks of severe and mild dyspnea ("perception") were differentially cued ("anticipation") and followed by intensity and unpleasantness ratings. In addition, volunteers indicated their anticipatory fear during the anticipation periods. There were no genotype-based group differences concerning dyspnea intensity and unpleasantness or brain activation during perception of sever…
Modifications induced on the amygdaloid paroxysmal activity by entopeduncolar or nigral injection of kainic acid, in the cat.
1983
Entopeduncolar or nigral injection of kainic acid determines an early decrease of the evoked amygdaloid paroxysmal activity and a later increase of the after discharge duration. This biphasic effect is likely due to the structural analogy of the drug with monosodium glutamate, a neuroexcitant amino acid. The data suggest that the basal ganglia exert a tonic control on the amygdaloid activity.
Happiness: role of dopamine and serotonin on mood and negative emotions
2017
Dopamine is a hormone associated with happiness and serotonin regulates our mood. When a person is physically attracted to another, an activation of dopamine, serotonin increased and production of oxytocin, a hormone that reduces pain perception and increases the emotional connection we have with the other occurs. Disconnecting the amygdala, the parts of the brain that are active against negative emotions like fear. The combination of all these elements leads to crush the other. After our beliefs, the way we understand ourselves and understand the world around us, eventually determining if I made a good choice. These are questions necessary to understand the functioning of our brain and hum…
The Role of the Amygdala in the Extinction of Conditioned Fear
2006
The amygdala has long been known to play a central role in the acquisition and expression of fear. More recently, convergent evidence has implicated the amygdala in the extinction of fear as well. In rodents, some of this evidence comes from the infusion of drugs directly into the amygdala and, in particular, into the basolateral complex of the amygdala, during or after extinction learning. In vivo electrophysiology has identified cellular correlates of extinction learning and memory in the lateral nucleus of that structure. Human imaging experiments also indicate that amygdaloid activity correlates with extinction training. In addition, some studies have directly identified changes in mole…
The medial amygdala as a key neural centre in maternal aggression: genetic, neural and behavioural analyses
2019
In rodents, as macrosmatic animals, chemosensory processing plays an instrumental role in guiding the expression of social, sexual and maternal behaviours. Social odours and pheromones are processed by the main and the accessory olfactory systems, which information converge mainly in the medial amygdala (Me). The Me, in turn, plays a central role in the vomeronasal–sensorimotor integration that leads to specific behavioural responses such as the above-mentioned social and maternal behaviours. Maternal behaviour comprises physiological and behavioural adaptations that help the dams to successfully raise their offspring. This behaviour is expressed in a wide range of vertebrate species and ca…
Impact of pharmacological and environmental manipulations on neuronal structural plasticity and dynamics
2017
El sistema nervioso de vertebrados es uno de los más estudiados, aunque peor comprendidos, del organismo de mamíferos. Desde que Ramón y Cajal postuló su teoría celular de este sistema (Ramón y Cajal 1909), la neurona se ha postulado como su unidad funcional. Sin embargo, durante las últimas décadas se ha revolucionado la visión que se tenía de éste. Una de las percepciones más asentadas era que, tras el desarrollo embrionario, el sistema nervioso se mantenía inmutable. Sin embargo, ahora sabemos que diferentes formas de plasticidad gobiernan su adaptación, que son necesarias para importantes procesos del día a día, tales como el aprendizaje y la memoria (Smythies 2002; Berlucchi and Buchte…
Amygdaloid projections to the ventral striatum in mice: direct and indirect chemosensory inputs to the brain reward system
2011
Rodents constitute good models for studying the neural basis of socio-sexual behaviour. Recent findings in mice have revealed the molecular identity of the some pheromonal molecules triggering intersexual attraction. However, the neural pathways mediating this basic socio-sexual behaviour remain elusive. Since previous work indicates that the dopaminergic tegmento-striatal pathway is not involved in pheromone reward, the present report explores alternative pathways linking the vomeronasal system with the tegmento-striatal system (the limbic basal ganglia) by means of tract-tracing experiments studying direct and indirect projections from the chemosensory amygdala to the ventral striato-pall…
Motherhood‐induced gene expression in the mouse medial amygdala: Changes induced by pregnancy and lactation but not by pup stimuli
2021
During lactation, adult female mice display aggressive responses toward male intrud-ers, triggered by male- derived chemosensory signals. This aggressive behavior is not shown by pup- sensitized virgin females sharing pup care with dams. The genetic mechanisms underlying the switch from attraction to aggression are unknown. In this work, we investigate the differential gene expression in lactating females ex-pressing maternal aggression compared to pup- sensitized virgin females in the me-dial amygdala (Me), a key neural structure integrating chemosensory and hormonal information. The results showed 197 genes upregulated in dams, including genes encoding hormones such as prolactin, growth h…