The Experts below are selected from a list of 1431 Experts worldwide ranked by ideXlab platform
R.g. Paredes - One of the best experts on this subject based on the ideXlab platform.
-
Olfactory preference and Fos expression in the accesory olfactory system of male rats with bilateral Lesions of the medial preoptic area/anterior Hypothalamus
Neuroscience, 2005Co-Authors: H.a. Hurtazo, R.g. ParedesAbstract:In the present study we evaluated if a medial preoptic area/anterior Hypothalamus Lesion affects the olfactory preference toward soiled bedding from receptive females in comparison to bedding from anestrous females or clean bedding. In the second part of the study we evaluated the accessory olfactory system response to estrous bedding with Fos immunoreactivity to determine if the preoptic Lesions modify the processing of sexually relevant olfactory cues. Before medial preoptic area/anterior Hypothalamus Lesions, male rats spent more time investigating estrous bedding as opposed to anestrous or clean bedding. After the Lesion, subjects showed no preference between estrous and anestrous bedding; that is, males spent the same amount of time investigating both types of bedding. These two odors were investigated more than clean bedding. Increments in Fos immunoreactivity neurons were seen in structures of the accessory olfactory system after exposure to soiled estrous bedding [granular layer of the accessory olfactory bulb, anterior-dorsal medial amygdala, posterior-dorsal medial amygdala, bed nucleus of the stria terminalis]. These results suggest that bilateral destruction of the medial preoptic area/anterior Hypothalamus modify male olfactory preference in such a way that subjects spend the same time smelling and investigating bedding from estrous and anestrous females. This change in olfactory preference is not associated with alterations in the processing of sexually relevant olfactory cues by the accessory olfactory system.
T. Issad - One of the best experts on this subject based on the ideXlab platform.
-
Increased mitogen-activated protein kinase expression and activity in white adipose tissue of ventromedial Hypothalamus-Lesioned rats
Diabetologia, 1997Co-Authors: M. Combettes-souverain, L. Pénicaud, P. Ferré, T. IssadAbstract:Ventromedial Hypothalamus Lesions in rats induce hyperphagia and hyperinsulinaemia associated with a rapid growth of white adipose tissue resulting in massive obesity. It has been shown previously that at an early stage after the Lesion, during the dynamic phase of obesity, the white adipose tissue is hyper-responsive to insulin. In the present work, we show that the effects of insulin on the autophosphorylation of the insulin receptor and on its tyrosine-kinase activity towards endogenous substrates are similar in intact adipocytes of control and ventromedial Hypothalamus Lesioned rats. One week after the Lesion, the expression of phosphatidylinisitol 3-kinase and RAF-1 kinase, evaluated by Western-blotting, was similar in control and ventromedial Hypothalamus Lesioned rats. In contrast, an important increase in the expression of extracellular signal regulated kinase 1 protein was observed in white adipose tissue of ventromedial Hypothalamus Lesioned compared to control animals. No difference in the expression of extracellular signal regulated kinase 1 mRNA was observed in adipose tissue of control and ventromedial Hypothalamus Lesioned rats, suggesting that a post-transcriptional mechanism is involved in the over-expression of extracellular signal regulated kinase 1. The kinase activity of extracellular signal regulated kinase 1 and 2 is also markedly increased in adipocytes of ventromedial Hypothalamus Lesioned compared to control rats, both in the basal state and after insulin stimulation. Six weeks after the ventromedial Hypothalamus Lesion, this increase in mitogen-activated protein kinase expression and activity was still observed in adipocytes of ventromedial Hypothalamus Lesioned rats. These results suggest that an early and sustained increase in the expression and activity of mitogen-activated protein kinase may participate in the development of white adipose tissue in ventromedial Hypothalamus Lesioned rats. [Diabetologia (1997) 40: 533–540]
H.a. Hurtazo - One of the best experts on this subject based on the ideXlab platform.
-
Olfactory preference and Fos expression in the accesory olfactory system of male rats with bilateral Lesions of the medial preoptic area/anterior Hypothalamus
Neuroscience, 2005Co-Authors: H.a. Hurtazo, R.g. ParedesAbstract:In the present study we evaluated if a medial preoptic area/anterior Hypothalamus Lesion affects the olfactory preference toward soiled bedding from receptive females in comparison to bedding from anestrous females or clean bedding. In the second part of the study we evaluated the accessory olfactory system response to estrous bedding with Fos immunoreactivity to determine if the preoptic Lesions modify the processing of sexually relevant olfactory cues. Before medial preoptic area/anterior Hypothalamus Lesions, male rats spent more time investigating estrous bedding as opposed to anestrous or clean bedding. After the Lesion, subjects showed no preference between estrous and anestrous bedding; that is, males spent the same amount of time investigating both types of bedding. These two odors were investigated more than clean bedding. Increments in Fos immunoreactivity neurons were seen in structures of the accessory olfactory system after exposure to soiled estrous bedding [granular layer of the accessory olfactory bulb, anterior-dorsal medial amygdala, posterior-dorsal medial amygdala, bed nucleus of the stria terminalis]. These results suggest that bilateral destruction of the medial preoptic area/anterior Hypothalamus modify male olfactory preference in such a way that subjects spend the same time smelling and investigating bedding from estrous and anestrous females. This change in olfactory preference is not associated with alterations in the processing of sexually relevant olfactory cues by the accessory olfactory system.
Guo-qing Zhu - One of the best experts on this subject based on the ideXlab platform.
-
Chemical Stimulation of Renal Tissue Induces Sympathetic Activation and a Pressor Response via the Paraventricular Nucleus in Rats.
Neuroscience bulletin, 2019Co-Authors: Yun Qiu, Feng Zhang, Ai-dong Chen, Hong Zhou, Jue-jin Wang, Qi Chen, Yu-ming Kang, Guo-qing ZhuAbstract:Sympathetic activation and the kidney play critical roles in hypertension and chronic heart failure. The role of the kidney in sympathetic activation is still not well known. In this study, we revealed an excitatory renal reflex (ERR) in rats induced by chemical stimulation of the kidney that regulated sympathetic activity and blood pressure. The ERR was induced by renal infusion of capsaicin, and evaluated by the changes in renal sympathetic outflow, blood pressure, and heart rate. Renal infusion of capsaicin dose-dependently increased the contralateral renal sympathetic nerve activity, mean arterial pressure, and heart rate. Capsaicin in the cortico-medullary border had greater effects than in the cortex or medulla. Intravenous infusion of capsaicin had no significant effects. The effects of renal infusion of capsaicin were abolished by ipsilateral renal denervation, but were not affected by bilateral sinoaortic denervation. Renal infusion of capsaicin increased the ipsilateral renal afferent activity. The ERR was also induced by renal infusion of bradykinin, adenosine, and angiotensin II, but not by ATP. Renal infusion of capsaicin increased c-Fos expression in the paraventricular nucleus (PVN) of Hypothalamus. Lesion of neurons in the PVN with kainic acid abolished the capsaicin-induced ERR. These findings indicate that chemical stimulation of kidney causes an excitatory reflex, leading to sympathetic activation, pressor response, and accelerated heart rate. The PVN is an important central nucleus in the pathway of the ERR.
M. Combettes-souverain - One of the best experts on this subject based on the ideXlab platform.
-
Increased mitogen-activated protein kinase expression and activity in white adipose tissue of ventromedial Hypothalamus-Lesioned rats
Diabetologia, 1997Co-Authors: M. Combettes-souverain, L. Pénicaud, P. Ferré, T. IssadAbstract:Ventromedial Hypothalamus Lesions in rats induce hyperphagia and hyperinsulinaemia associated with a rapid growth of white adipose tissue resulting in massive obesity. It has been shown previously that at an early stage after the Lesion, during the dynamic phase of obesity, the white adipose tissue is hyper-responsive to insulin. In the present work, we show that the effects of insulin on the autophosphorylation of the insulin receptor and on its tyrosine-kinase activity towards endogenous substrates are similar in intact adipocytes of control and ventromedial Hypothalamus Lesioned rats. One week after the Lesion, the expression of phosphatidylinisitol 3-kinase and RAF-1 kinase, evaluated by Western-blotting, was similar in control and ventromedial Hypothalamus Lesioned rats. In contrast, an important increase in the expression of extracellular signal regulated kinase 1 protein was observed in white adipose tissue of ventromedial Hypothalamus Lesioned compared to control animals. No difference in the expression of extracellular signal regulated kinase 1 mRNA was observed in adipose tissue of control and ventromedial Hypothalamus Lesioned rats, suggesting that a post-transcriptional mechanism is involved in the over-expression of extracellular signal regulated kinase 1. The kinase activity of extracellular signal regulated kinase 1 and 2 is also markedly increased in adipocytes of ventromedial Hypothalamus Lesioned compared to control rats, both in the basal state and after insulin stimulation. Six weeks after the ventromedial Hypothalamus Lesion, this increase in mitogen-activated protein kinase expression and activity was still observed in adipocytes of ventromedial Hypothalamus Lesioned rats. These results suggest that an early and sustained increase in the expression and activity of mitogen-activated protein kinase may participate in the development of white adipose tissue in ventromedial Hypothalamus Lesioned rats. [Diabetologia (1997) 40: 533–540]