Chronic lability of arterial pressure produced by selective destruction of the catecholamine innervation of the nucleus tractus solitarii in the rat.

Snyder, David W.; Nathan, Marc A.; Reis, Donald J.

doi:10.1161/01.res.43.4.662

Cited by 89 publications

(55 citation statements)

References 36 publications

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“…a catheter was implanted for recording systemic arterial pressure. Procedures for implantation and maintenance of catheters have been described (Snyder et al, 1978;LeDoux et al, 1982). In brief, the animals were anesthetized with halothane (2.5% in 100% oxygen).…”

Section: Placement Of Brain Lesionsmentioning

confidence: 99%

Different projections of the central amygdaloid nucleus mediate autonomic and behavioral correlates of conditioned fear

et al. 1988

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The purpose of the present study was to determine whether lesions of areas projected to by the central amygdaloid nucleus (ACE) would disrupt the classical conditioning of autonomic and/or behavioral emotional responses. The areas studied included 3 projection targets of the ACE: the lateral hypothalamic area (LH), midbrain central gray (CG) region, and bed nucleus of the stria terminalis (BNST). Lesions were made either electrolytically or by microinjection of ibotenic acid, which destroys local neurons without interrupting fibers of passage. Two weeks later, the animals were classically conditioned by pairing an acoustic stimulus with footshock. The next day, conditioned changes in autonomic activity (increases in arterial pressure) and emotional behavior (“freezing,” or the arrest of somatomotor activity) evoked by the acoustic conditioned stimulus (CS) were measured during extinction trials. Electrolytic and ibotenic acid lesions of the LH interfered with the conditioned arterial pressure response, but did not affect conditioned freezing. Electrolytic lesions of the rostral CG disrupted conditioned freezing but not conditioned changes in arterial pressure. Ibotenic acid injected into the rostral CG reduced neither the arterial pressure nor the freezing response. Injection of ibotenic acid in the caudal CG, like electrolytic lesions of the rostral CG, disrupted the freezing, but not the arterial pressure response. Injection of ibotenic acid into the BNST had no effect on either response. These data demonstrate that neurons in the LH are involved in the autonomic, but not the behavioral, conditioned response pathway, whereas neurons in the caudal CG are involved in the behavioral, but not the autonomic, pathway. Different efferent projections of the central amygdala thus appear to mediate the behavioral and autonomic concomitants of conditioned fear.

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Section: Placement Of Brain Lesionsmentioning

confidence: 99%

Different projections of the central amygdaloid nucleus mediate autonomic and behavioral correlates of conditioned fear

et al. 1988

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“…It is also important to note that hydrogen peroxide, a major superoxide metabolite, is accessible to the extracellular milieu (Lambeth, 2004) and thus may influence closely apposed structures. Thus, catecholamine signaling in the mNTS, which is known to play a role in the regulation of systemic arterial pressure (Snyder et al, 1978), may be directly modulated by superoxide generated by NADPH oxidase in neurons, or indirectly in apposed astroglia.…”

Section: Tyrosine Hydroxylase and Phox Proteins In Mnts Neurons And Gmentioning

confidence: 99%

“…Catecholaminergic neurons in mNTS are sensitive to disturbance of cardiovascular (Chan et al, 1999), respiratory (Buller et al, 1999), fluid (Gordon et al, 1979), and metabolic (Willing and Berthoud, 1997) homeostasis. In addition, catecholamine containing axon terminals within the mNTS play an important modulatory role in the central regulation of systemic arterial pressure (Snyder et al, 1978). There is also an increase in TH activity in the NTS associated with rodent models of hypertension (Misu et al, 1995, Potts et al, 2000., Ferrari et al, 2002.…”

Section: Introductionmentioning

confidence: 99%

Subcellular localization of nicotinamide adenine dinucleotide phosphate oxidase subunits in neurons and astroglia of the rat medial nucleus tractus solitarius: Relationship with tyrosine hydroxylase immunoreactive neurons

et al. 2006

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Superoxide produced by the enzyme NADPH oxidase mediates crucial intracellular signaling cascades in the mNTS, a brain region populated by catecholaminergic neurons, as well as astroglia that play an important role in autonomic function. The mechanisms mediating NADPH oxidase (phox) activity in the neural regulation of cardiovascular processes are incompletely understood, however the subcellular localization of superoxide produced by the enzyme is likely to be an important regulatory factor. We used immunogold electron microscopy to determine the phenotypic and subcellular localization of the NADPH oxidase subunits p47 phox , gp91 phox, and p22 phox in the mNTS. The mNTS contains a large population of neurons that synthesize catecholamines. Significantly, catecholaminergic signaling can be modulated by redox reactions. Therefore, the relationship of NADPH oxidase subunit labeled neurons or glia with respect to catecholaminergic neurons was also determined by dual labeling for the superoxide producing enzyme and tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine biosynthesis. In the mNTS, NADPH oxidase subunits were present primarily in somatodendritic processes and astrocytes, some of which also contained TH, or were contacted by TH labeled axons, respectively. Immunogold quantification of NADPH oxidase subunit localization showed that p47 phox and gp91 phox were present on the surface membrane, as well as vesicular organelles characteristic of calcium storing smooth endoplasmic reticula in dendritic and astroglial processes. These results indicate that NADPH oxidase assembly and consequent superoxide formation are likely to occur near the plasmalemma, as well as on vesicular organelles associated with intracellular calcium storage within mNTS neurons and glia. Thus, NADPH oxidase-derived superoxide may participate in intracellular signaling pathways linked to calcium regulation in diverse mNTS cell types. Moreover, NADPH oxidase-derived superoxide in neurons and glia may directly or indirectly modulate catecholaminergic neuron activity in the mNTS.

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“…The two areas receive substantial noradrenergic input, and experimentally induced increases and decreases in blood pressure correlate with reductions and elevations, respectively, of catecholamine release in these nuclei (Yamazaki & Ninomiya, 1993;Singewald & Philippu, 1996). Selective lesion of catecholaminergic terminals in the NTS or RVLM of rats impairs the baroreceptor reflex function (Snyder et al, 1978;Granata et al, 1983). Also, a 2A -adrenoceptors are densely expressed in both nuclei (Scheinin et al, 1994;Tavares et al, 1996), and activation of these receptors seems to represent the main mechanism of the cardioinhibitory and hypotensive effect of clonidine-like a 2 -adrenoceptor agonists (Guyenet et al, 1995;Vayssettes-Courchay et al, 2002;Szabo, 2002).…”

Section: Discussionmentioning

confidence: 99%

Modulation of the baroreceptor reflex by α_2A‐adrenoceptors: a study in α_2A knockout mice

Niederhoffer¹,

Hein²,

Starke³

2004

British J Pharmacology

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1 Our objective was to determine whether a 2A -adrenoceptors modulate the baroreceptor reflex. The efficacy of the reflex was evaluated by measuring the spontaneous blood pressure and heart rate variability at rest and the heart rate responses to evoked changes in blood pressure. Experiments were carried out in conscious, unrestrained, and anaesthetized a 2A -adrenoceptor-deficient (a 2A -KO) mice and WT mice. 2 In conscious a 2A -KO mice, the spontaneous blood pressure variability was greater, and the spontaneous heart rate variability was lower than in conscious WT mice. This was also observed in anaesthetized animals. 3 The reflex bradycardia after intravenous injection of phenylephrine was greatly attenuated in conscious a 2A -KO compared to conscious WT mice; the baroreceptor reflex gain (ratio maximal change in heart rate/maximal change in mean arterial pressure) was decreased by 40%. 4 Similar results were obtained when reflex bradycardia was elicited by intra-arterial volume loading of conscious WT and a 2A -KO mice. The baroreceptor reflex gain upon volume loading was also low in anaesthetized a 2A -KO mice. 5 The reflex tachycardia evoked by intravenous sodium nitroprusside injection was also significantly less in a 2A -KO mice as compared to WT, conscious as well as anaesthetized; the baroreceptor reflex gains were decreased by 50 and 65%, respectively. 6 Direct stimulation of cardiac b-adrenoceptors by the agonist isoprenaline produced similar cardioacceleration in a 2A -KO and WT animals. 7 Our results show that the baroreceptor reflex function is impaired in mice lacking a 2A -adrenoceptors. We conclude that central a 2A -adrenoceptors facilitate the reflex response to both loading and unloading of the arterial baroreceptors.

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Chronic lability of arterial pressure produced by selective destruction of the catecholamine innervation of the nucleus tractus solitarii in the rat.

Cited by 89 publications

References 36 publications

Different projections of the central amygdaloid nucleus mediate autonomic and behavioral correlates of conditioned fear

Different projections of the central amygdaloid nucleus mediate autonomic and behavioral correlates of conditioned fear

Subcellular localization of nicotinamide adenine dinucleotide phosphate oxidase subunits in neurons and astroglia of the rat medial nucleus tractus solitarius: Relationship with tyrosine hydroxylase immunoreactive neurons

Modulation of the baroreceptor reflex by α_2A‐adrenoceptors: a study in α_2A knockout mice

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Chronic lability of arterial pressure produced by selective destruction of the catecholamine innervation of the nucleus tractus solitarii in the rat.

Cited by 89 publications

References 36 publications

Different projections of the central amygdaloid nucleus mediate autonomic and behavioral correlates of conditioned fear

Different projections of the central amygdaloid nucleus mediate autonomic and behavioral correlates of conditioned fear

Subcellular localization of nicotinamide adenine dinucleotide phosphate oxidase subunits in neurons and astroglia of the rat medial nucleus tractus solitarius: Relationship with tyrosine hydroxylase immunoreactive neurons

Modulation of the baroreceptor reflex by α2A‐adrenoceptors: a study in α2A knockout mice

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Modulation of the baroreceptor reflex by α_2A‐adrenoceptors: a study in α_2A knockout mice