Anatomical evidence of direct projections from the nucleus of the solitary tract to the hypothalamus, amygdala, and other forebrain structures in the rat

1978 ◽  
Vol 153 (1) ◽  
pp. 1-26 ◽  
Author(s):  
Juarez A. Ricardo ◽  
Edward Tongju Koh
Keyword(s):  
Solitary Tract ◽  
Anatomical Evidence

Synaptic organization of the gustatory NST

1994 ◽  
Vol 52 ◽  
pp. 150-151
Author(s):  
M. C. Whitehead
Keyword(s):  
Central Nervous System ◽  
Dendritic Spines ◽  
Fundamental Problem ◽  
Cell Types ◽  
Brain Regions ◽  
Excitatory Synapses ◽  
Solitary Tract ◽  
Synaptic Organization ◽  
Synaptic Junctions ◽  
Afferent Terminals

A fundamental problem in taste research is to determine how gustatory signals are processed and disseminated in the mammalian central nervous system. An important first step toward understanding information processing is the identification of cell types in the nucleus of the solitary tract (NST) and their synaptic relationships with oral primary afferent terminals. Facial and glossopharyngeal (LIX) terminals in the hamster were labelled with HRP, examined with EM, and characterized as containing moderate concentrations of medium-sized round vesicles, and engaging in asymmetrical synaptic junctions. Ultrastructurally the endings resemble excitatory synapses in other brain regions.Labelled facial afferent endings in the RC subdivision synapse almost exclusively with distal dendrites and dendritic spines of NST cells. Most synaptic relationships between the facial synapses and the dendrites are simple. However, 40% of facial endings engage in complex synaptic relationships within glomeruli containing unlabelled axon endings particularly ones termed "SP" endings. SP endings are densely packed with small, pleomorphic vesicles and synapse with both the facial endings and their postsynaptic dendrites by means of nearly symmetrical junctions.

scholarly journals Central afferents to the nucleus of the solitary tract in rats and mice

2020 ◽  
Vol 528 (16) ◽  
pp. 2708-2728 ◽  
Author(s):  
Silvia Gasparini ◽  
Jacob M. Howland ◽  
Andrew J. Thatcher ◽  
Joel C. Geerling
Keyword(s):  
Solitary Tract ◽  
Rats And Mice

Targeting angiotensin type-2 receptors located on pressor neurons in the nucleus of the solitary tract to relieve hypertension in mice

2021 ◽  
Author(s):  
Mazher Mohammed ◽  
Dominique N Johnson ◽  
Lei A Wang ◽  
Scott W Harden ◽  
Wanhui Sheng ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Gaba Release ◽  
Access Point ◽  
Central Administration ◽  
Solitary Tract ◽  
Arterial Blood ◽  
Pressor Responses ◽  
Pressure Lowering ◽  
Angiotensin Type

Abstract Aims These studies evaluate whether angiotensin type-2 receptors (AT2Rs) that are expressed on γ-aminobutyric acid (GABA) neurons in the nucleus of the solitary tract (NTS) represent a novel endogenous blood pressure-lowering mechanism. Methods and results Experiments combined advanced genetic and neuroanatomical techniques, pharmacology, electrophysiology, and optogenetics in mice to define the structure and cardiovascular-related function of NTS neurons that contain AT2R. Using mice with Cre-recombinase directed to the AT2R gene, we discovered that optogenetic stimulation of AT2R-expressing neurons in the NTS increases GABA release and blood pressure. To evaluate the role of the receptor, per se, in cardiovascular regulation, we chronically delivered C21, a selective AT2R agonist, into the brains of normotensive mice and found that central AT2R activation reduces GABA-related gene expression and blunts the pressor responses induced by optogenetic excitation of NTS AT2R neurons. Next, using in situ hybridization, we found that the levels of Agtr2 mRNAs in GABAergic NTS neurons rise during experimentally induced hypertension, and we hypothesized that this increased expression may be exploited to ameliorate the disease. Consistent with this, final experiments revealed that central administration of C21 attenuates hypertension, an effect that is abolished in mice lacking AT2R in GABAergic NTS neurons. Conclusion These studies unveil novel hindbrain circuits that maintain arterial blood pressure, and reveal a specific population of AT2R that can be engaged to alleviate hypertension. The implication is that these discrete receptors may serve as an access point for activating an endogenous depressor circuit.

The dorsomedial hypothalamus and nucleus of the solitary tract as key regulators in a rat model of chronic obesity

2020 ◽  
Vol 1727 ◽  
pp. 146538
Author(s):  
Chen Zhang ◽  
Pernille Barkholt ◽  
Jens Christian Nielsen ◽  
Ditte Dencker Thorbek ◽  
Kristoffer Rigbolt ◽  
...  
Keyword(s):  
Rat Model ◽  
Solitary Tract ◽  
Dorsomedial Hypothalamus

Rat brainstem neurons responsive to changes in portal blood sodium concentration

1984 ◽  
Vol 247 (5) ◽  
pp. R792-R799 ◽  
Author(s):  
P. J. Kahrilas ◽  
R. C. Rogers
Keyword(s):  
Hypertonic Saline ◽  
Choline Chloride ◽  
Vena Cava ◽  
Sodium Concentration ◽  
Portal Blood ◽  
Solitary Tract ◽  
Sprague Dawley ◽  
Response Characteristics ◽  
Medial Nucleus ◽  
Rat Brainstem

Studies were performed to identify the response characteristics of nucleus of the solitary tract neurons receiving afferent projections from the hepatic branch of the vagus nerve. Thirty Sprague-Dawley rats under pentobarbital anesthesia had catheters placed in the ileocolic vein and the inferior vena cava. Neuronal recordings were made in the left medial nucleus of the solitary tract (NST), in the area where hepatic vagal fibers terminate. Sixteen NST cells were identified that responded selectively to the portal infusion of water or hypertonic saline. Two patterns of response were seen: 1) 12 neurons were persistently stimulated by portal hypertonic saline and persistently inhibited by portal water, and 2) four neurons were either transiently excited (n = 3) or transiently inhibited (n = 1) by portal hypertonic saline with no water effect. All units recorded responded to changes of 1% or less in portal blood sodium concentration. Hypertonic mannitol was an ineffective stimulus but choline chloride was as effective as sodium chloride. This suggests that the hepatic receptors utilize an Na+-K+-ATPase electrogenic pump in the transduction process.

Sodium-deficient diet reduces gustatory activity in the nucleus of the solitary tract of behaving rats

1995 ◽  
Vol 269 (3) ◽  
pp. R647-R661 ◽  
Author(s):  
K. Nakamura ◽  
R. Norgren
Keyword(s):  
Citric Acid ◽  
Dietary Sodium ◽  
Solitary Tract ◽  
Deficient Diet ◽  
Dietary Condition ◽  
Response Profiles ◽  
The Mean ◽  
Response To Water ◽  
Gustatory Neurons ◽  
General Reduction

The activity of single taste neurons was recorded from the nucleus of the solitary tract before (n = 41) and after (n = 58) awake, behaving rats were switched to a sodium-free diet. During sodium deprivation, the spontaneous activity of the neurons increased (142%), but responses to water and sapid stimuli decreased. For all neurons in the sample, the mean response to water decreased to 72% of its predeprivation level, NaCl dropped to 53%, sucrose to 41%, citric acid to 68%, and quinine HCl to 84%. Despite the drop in magnitude, the response profiles of the taste neurons were not changed by the dietary condition. In the Na-replete state, 61% of the activity elicited by NaCl occurred in NaCl-best cells and 33% in sucrose-best neurons. In the depleted state, these values were 60 and 26%, respectively. Nevertheless, at the highest concentrations tested, deprivation did alter the relative responsiveness of the gustatory neurons to sucrose and NaCl in specific categories of neurons. Compared with acute preparations, dietary sodium deprivation in awake, behaving rats produced a more general reduction in the gustatory responses of neurons in the nucleus of the solitary tract. The largest reductions in elicited activity occurred for the "best stimulus" of a particular neuron, thus leading to smaller differences in response magnitude across stimuli, particularly at the highest concentrations tested.

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