Subcortical sites mediating sympathetic responses from insular cortex in rats

Stimulation of the insular cortex elicits a number of autonomic responses. The insular cortex projects directly to the lateral hypothalamic area, the parabrachial nucleus, and the nucleus of the solitary tract, which in turn project directly to sympathetic preganglionic areas. To determine which of these subcortical sites mediates sympathetic responses evoked from the insular cortex, changes in renal nerve activity were recorded before and after injection of the synaptic blocking agent cobalt into each of these regions. Blood pressure, heart rate, and renal nerve activity were continuously monitored in chloralose or urethan-anesthetized rats. Single-pulse electrical stimulation (200 microA, 1 ms) elicited either an early increase or decrease in renal nerve activity from pressor and depressor sites, respectively, in the insular cortex. Cobalt injections (500 nl) into the lateral hypothalamic area attenuated the nerve response 10-100%. Cobalt injections into the nucleus of the solitary tract significantly enhanced the initial increase in the nerve response obtained from pressor sites in the insular cortex. Injections into the parabrachial nucleus did not affect the nerve responses. These results suggest that there is a mandatory synapse in the lateral hypothalamic area in the pathway from the insular cortex to the sympathetic nervous system.

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Receptors in lateral hypothalamic area involved in insular cortex sympathetic responses

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1998.275.2.h689 ◽

1998 ◽

Vol 275 (2) ◽

pp. H689-H696 ◽

Cited By ~ 3

Author(s):

Kenneth S. Butcher ◽

David F. Cechetto

Keyword(s):

Heart Rate ◽

Arterial Pressure ◽

Sympathetic Nerve ◽

Lateral Hypothalamic Area ◽

Ventrolateral Medulla ◽

Bipolar Electrode ◽

Hypothalamic Area ◽

Renal Nerve ◽

Lateral Hypothalamic ◽

Sympathetic Responses

Previous evidence has shown that sympathetic nerve responses to insular cortical (IC) stimulation are mediated by synapses within the lateral hypothalamic area (LHA) and ventrolateral medulla. The present study determined the receptor(s) involved at the synapse in the LHA associated with stimulation-evoked IC sympathetic responses. Twenty-seven male Wistar rats were instrumented for renal nerve activity, arterial pressure, and heart rate recording. The right IC was stimulated with a bipolar electrode (200–1,000 μA, 2 ms, 0.8 Hz) resulting in sympathetic nerve responses. Antagonists were then pressure injected into the ipsilateral LHA (300–500 nl). Kynurenate (250 mM) injections resulted in 51 ± 8% (range 0–100%) block of IC-stimulated sympathetic nerve responses. Similarly, the N-methyl-d-aspartic acid (NMDA)-receptor antagonistdl-2-amino-5-phosphonopentanoic acid (200 μM) resulted in an inhibition (82 ± 8%; range 51–100%) of IC-stimulated sympathetic responses. Injection of the non-NMDA antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (200 μM) had no effect on IC sympathetic responses. Injection of antagonists to GABA, acetylcholine, and adrenergic receptors was also without effect. No antagonist injections had any effects on baseline sympathetic nerve discharge, arterial pressure, or heart rate. These results suggest that the IC autonomic efferents projecting to the LHA utilize NMDA glutamatergic receptors.

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Lateral hypothalamic area neurotransmission and neuromodulation of the specific cardiac effects of insular cortex stimulation

Brain Research ◽

10.1016/0006-8993(92)90352-a ◽

1992 ◽

Vol 581 (1) ◽

pp. 133-142 ◽

Cited By ~ 46

Author(s):

Stephen M. Oppenheimer ◽

Tarek Saleh ◽

David F. Cechetto

Keyword(s):

Insular Cortex ◽

Lateral Hypothalamic Area ◽

Hypothalamic Area ◽

Cardiac Effects ◽

Lateral Hypothalamic

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The region of the pontine parabrachial nucleus is a major target of dehydration-sensitive CRH neurons in the rat lateral hypothalamic area

The Journal of Comparative Neurology ◽

10.1002/(sici)1096-9861(19980427)394:1<48::aid-cne5>3.0.co;2-h ◽

1998 ◽

Vol 394 (1) ◽

pp. 48-63 ◽

Cited By ~ 36

Author(s):

Andrea B. Kelly ◽

Alan G. Watts

Keyword(s):

Lateral Hypothalamic Area ◽

Parabrachial Nucleus ◽

Hypothalamic Area ◽

Lateral Hypothalamic ◽

Major Target

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Different cardiac and renal inhibitory and excitatory areas in rabbit hypothalamus

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1983.244.6.h832 ◽

1983 ◽

Vol 244 (6) ◽

pp. H832-H838 ◽

Cited By ~ 4

Author(s):

Y. Okada ◽

I. Ninomiya

Keyword(s):

Sympathetic Nerve ◽

Sympathetic Nerve Activity ◽

New Method ◽

Cardiac Sympathetic Nerve ◽

Nerve Activity ◽

Hypothalamic Area ◽

Renal Nerve ◽

Cardiac Sympathetic Nerve Activity ◽

Renal Nerve Activity ◽

The Right

The hypothalamic area was stimulated in anesthetized rabbits at a large number of selected points, and the effects on the simultaneously recorded right cardiac sympathetic nerve activity (CSNA) and renal nerve activity (RNA) were analyzed quantitatively. Four characteristic patterns of CSNA and RNA responses could be observed. The most striking finding was the presence of opposite responses of CSNA and RNA at many hypothalamic stimulus points, in addition to the conventionally observed CSNA and RNA responses in the same direction. By a new method, we drew hypothalamic maps for CSNA and RNA response magnitudes. These maps show that the excitatory areas of CSNA and RNA are surrounded by respective inhibitory areas. Although the excitatory areas of CSNA and RNA correspond with each other on the right side, they are not identical on the left side. These data suggest that the heart and kidney are controlled by sympathetic nerve activities originating from different hypothalamic neural groups in the rabbit.

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Glucoreceptor Systems: FFrom Control of Glycemia to Feeding Behavior

Physiology ◽

10.1152/physiologyonline.1990.5.2.46 ◽

1990 ◽

Vol 5 (2) ◽

pp. 46-49 ◽

Cited By ~ 1

Author(s):

C Timo-Iaria

Keyword(s):

Feeding Behavior ◽

Metabolic Activity ◽

Lateral Hypothalamic Area ◽

Solitary Tract ◽

Normal Range ◽

Hypothalamic Area ◽

Lateral Hypothalamic

Hypoglycemia activates glucoreceptors in the lateral hypothalamic area, nuclei of the solitary tract, and liver and provokes reflexes that help maintain glycemia within the normal range. The metabolic activity thus induced seems to trigger hunger and subsequent feeding.

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Neurons in the lateral hypothalamic area and zona incerta with ascending projections to the subfornical organ area in the rat

Brain Research ◽

10.1016/0006-8993(88)90247-8 ◽

1988 ◽

Vol 456 (2) ◽

pp. 397-400 ◽

Cited By ~ 14

Author(s):

Junichi Tanaka ◽

Katsuo Seto

Keyword(s):

Subfornical Organ ◽

Lateral Hypothalamic Area ◽

Zona Incerta ◽

Hypothalamic Area ◽

Lateral Hypothalamic

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Neuronal regulation of renal function: A model system for nervous system interactions

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y92-097 ◽

1992 ◽

Vol 70 (5) ◽

pp. 733-734 ◽

Cited By ~ 1

Author(s):

J. Michael Wyss

Keyword(s):

Nervous System ◽

Renal Function ◽

Renal Disease ◽

Easy Access ◽

Renal Nerves ◽

Clinical Consequence ◽

Nerve Activity ◽

Renal Nerve ◽

Renal Nerve Activity

The kidney is the most highly innervated peripheral organ, and both the excretory and endocrine functions of the kidney are regulated by renal nerve activity. The kidney plays a dominant role in body fluid homeostasis, blood ionic concentration, and pH and thereby contributes importantly to systemic blood pressure control. Early studies suggested that the neural-renal interactions were responsible only for short-term adjustments in renal function, but more recent studies indicate that the renal nerves may be a major contributor to chronic renal defects leading to established hypertension and (or) renal disease. The neural-renal interaction is also of considerable interest as a model to elucidate the interplay between the nervous system and peripheral organs, since there is abundant anatomical and physiological information characterizing the renal nerves. The investigator has easy access to the renal nerves and the neural influence on renal function is directly quantifiable both in vivo and in vitro. In this symposium that was presented at the 1990 annual convention of the Society for Neuroscience in St. Louis, Missouri, three prominent researchers evaluate the most recent progress in understanding the interplay between the nervous system and the kidney and explore how the results of these studies relate to the broader questions concerning the nervous system's interactions.First, Luciano Barajas examines the detailed anatomy of the intrarenal distribution of the efferent and afferent renal nerves along the nephron and vasculature, and he evaluates the physiological role of each of the discrete components of the innervation. His basic science orientation combined with his deep appreciation of the clinical consequence of the failure of neural-renal regulation enhances his discussion of the anatomy. Ulla C. Kopp discusses the role of the renorenal reflex, which alters renal responses following stimulation of the contralateral kidney. She also considers her recent findings that efferent renal nerve activity can directly modify sensory feedback to the spinal cord from the kidney. Finally, J. Michael Wyss examines the functional consequences of neural control of the kidney in health and disease. Although the nervous system has often been considered as only an acute regulator of visceral function, current studies into hypertension and renal disease suggest that neural-renal dysfunction may be an important contributor to chronic diseases.Together, these presentations examine most of the recent advances in the area of neural-renal interactions and point out how these data form a basis for future research into neuronal interactions with all visceral organs. The relative simplicity of the neural-renal interaction makes this system an important model with which to elucidate all neural-peripheral and neural-neural interactions.

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