Allopregnanolone Effects on Transmission in the Brain Stem Solitary Tract Nucleus (NTS)

Neuroscience ◽  
2018 ◽  
Vol 379 ◽  
pp. 219-227 ◽  
Author(s):  
Sojin Kim ◽  
Sung-Moon Kim ◽  
Bermseok Oh ◽  
Jihoon Tak ◽  
Eunhee Yang ◽  
...  
Keyword(s):  
Brain Stem ◽  
Solitary Tract Nucleus ◽  
Solitary Tract ◽  
The Brain

scholarly journals Independent transmission of convergent visceral primary afferents in the solitary tract nucleus

2013 ◽  
Vol 109 (2) ◽  
pp. 507-517 ◽  
Author(s):  
Stuart J. McDougall ◽  
Michael C. Andresen
Keyword(s):  
Potential Interaction ◽  
Primary Afferents ◽  
Second Order ◽  
Solitary Tract Nucleus ◽  
Solitary Tract ◽  
Multiple Contacts ◽  
Large Numbers ◽  
Response Profiles ◽  
Active Release ◽  
The Brain

Cranial primary afferents from the viscera enter the brain at the solitary tract nucleus (NTS), where their information is integrated for homeostatic reflexes. The organization of sensory inputs is poorly understood, despite its critical impact on overall reflex performance characteristics. Single afferents from the solitary tract (ST) branch within NTS and make multiple contacts onto individual neurons. Many neurons receive more than one ST input. To assess the potential interaction between converging afferents and proximal branching near to second-order neurons, we probed near the recorded soma in horizontal slices from rats with focal electrodes and minimal shocks. Remote ST shocks evoked monosynaptic excitatory postsynaptic currents (EPSCs), and nearby focal shocks also activated monosynaptic EPSCs. We tested the timing and order of stimulation to determine whether focal shocks influenced ST responses and vice versa in single neurons. Focal-evoked EPSC response profiles closely resembled ST-EPSC characteristics. Mean synaptic jitters, failure rates, depression, and phenotypic segregation by capsaicin responsiveness were indistinguishable between focal and ST-evoked EPSCs. ST-EPSCs failed to affect focal-EPSCs within neurons, indicating that release sites and synaptic terminals were functionally independent and isolated from cross talk or neurotransmitter overflow. In only one instance, focal shocks intercepted and depleted the ST axon generating evoked EPSCs. Despite large numbers of functional contacts, multiple afferents do not appear to interact, and ST axon branches may be limited to close to the soma. Thus single or multiple primary afferents and their presynaptic active release sites act independently when they contact single second-order NTS neurons.

Focal warming in the nucleus of the solitary tract prolongs the laryngeal chemoreflex in decerebrate piglets

2007 ◽  
Vol 102 (1) ◽  
pp. 54-62 ◽  
Author(s):  
L. Xia ◽  
T. A. Damon ◽  
J. C. Leiter ◽  
D. Bartlett
Keyword(s):  
Brain Stem ◽  
Brain Tissue ◽  
Rectal Temperature ◽  
Respiratory Activity ◽  
Nucleus Ambiguus ◽  
Tissue Temperature ◽  
Whole Body ◽  
Solitary Tract ◽  
Neonatal Piglets ◽  
The Brain

The laryngeal chemoreflex (LCR), elicited by a drop of water in the larynx, is exaggerated by mild hyperthermia (body temperature = 40–41°C) in neonatal piglets. We tested the hypothesis that thermal prolongation of the LCR results from heating the nucleus of the solitary tract (NTS), where laryngeal afferents first form synapses in the brain stem. Three- to 13-day-old piglets were decerebrated and vagotomized and studied without anesthesia while paralyzed and ventilated. Phrenic nerve activity and rectal temperature were recorded. A thermode was placed in the medulla, and the brain tissue temperature was recorded with a thermistor ∼1 mm from the tip of the thermode. When the thermode was inserted into the brain stem, respiratory activity was arrested or greatly distorted in eight animals. However, the thermode was inserted in nine animals without disrupting respiratory activity, and in these animals, warming the medullary thermode (thermistor temperature = 40–41°C) while holding rectal temperature constant reversibly exaggerated the LCR. The caudal raphé was warmed focally by ∼2°C in four additional animals; this did not alter the duration of the LCR in these animals. Thermodes placed in the NTS did not disrupt respiratory activity, but they did prolong the LCR when warmed. Thermodes that were placed deep to the NTS in the region of the nucleus ambiguus disrupted respiratory activity, which precluded any analysis of the LCR. We conclude that prolongation of the laryngeal chemoreflex by whole body hyperthermia originates from the elevation of brain tissue temperature within in the NTS.

Food entrainment modifies the c-Fos expression pattern in brain stem nuclei of rats

2005 ◽  
Vol 288 (3) ◽  
pp. R678-R684 ◽  
Author(s):  
Manuel Ángeles-Castellanos ◽  
Jorge Mendoza ◽  
Mauricio Díaz-Muñoz ◽  
Carolina Escobar
Keyword(s):  
Brain Stem ◽  
Neural Systems ◽  
Solitary Tract ◽  
Hypothalamic Nuclei ◽  
Food Anticipatory Activity ◽  
Neural Information ◽  
Meal Time ◽  
Differential Involvement ◽  
Anticipatory Activity ◽  
The Brain

When food is restricted to a few hours daily, animals increase their locomotor activity 2–3 h before food access, which has been termed food anticipatory activity. Food entrainment has been linked to the expression of a circadian food-entrained oscillator (FEO) and the anatomic substrate of this oscillator seems to depend on diverse neural systems and peripheral organs. Previously, we have described a differential involvement of hypothalamic nuclei in the food-entrained process. For the food entrainment pathway, the communication between the gastrointestinal system and central nervous system is essential. The visceral synaptic input to the brain stem arrives at the dorsal vagal complex and is transmitted directly from the nucleus of the solitary tract (NST) or via the parabrachial nucleus (PBN) to hypothalamic nuclei and other areas of the forebrain. The present study aims to characterize the response of brain stem structures in food entrainment. The expression of c-Fos immunoreactivity (c-Fos-IR) was used to identify neuronal activation. Present data show an increased c-Fos-IR following meal time in all brain stem nuclei studied. Food-entrained temporal patterns did not persist under fasting conditions, indicating a direct dependence on feeding-elicited signals for this activation. Because NST and PBN exhibited a different and increased response from that expected after a regular meal, we suggest that food entrainment promotes ingestive adaptations that lead to a modified activation in these brain stem nuclei, e.g., stomach distension. Neural information provided by these nuclei to the brain may provide the essential entraining signal for FEO.

Neuroanatomic organization of the parasympathetic bronchomotor system in developing sheep

1997 ◽  
Vol 273 (1) ◽  
pp. R121-R133 ◽  
Author(s):  
J. J. Perez Fontan ◽  
C. R. Velloff
Keyword(s):  
Brain Stem ◽  
Pseudorabies Virus ◽  
Respiratory Muscles ◽  
Ventrolateral Medulla ◽  
Solitary Tract ◽  
Preganglionic Neurons ◽  
Vagal Innervation ◽  
Ventral Medullary Surface ◽  
Trachealis Muscle ◽  
The Brain

We applied two complementary retrograde labeling techniques to characterize the organization of the brain stem neuronal network responsible for the vagal innervation of the trachealis muscle in developing sheep. Single neuronal labeling produced by injections of the beta-subunit of cholera toxin into the muscle in newborn lambs showed that airway vagal preganglionic neurons are located exclusively in the nucleus ambiguous and nucleus of the solitary tract. Transneuronal labeling produced by similar injections of the Bartha strain of the pseudorabies virus in sheep fetuses demonstrated that these airway vagal preganglionic neurons receive inputs from a small number of neurons in brain stem areas known to participate in premotor control of the respiratory muscles (ventral respiratory group), chemoreception (nucleus of the solitary tract and ventral medullary surface), and cardiovascular and respiratory regulation (raphe nuclei, ventrolateral medulla, and noradrenergic groups of the medulla and pons). We conclude that the vagal preganglionic neurons that project to airway smooth muscle are already integrated in the control of breathing before birth in sheep.

Melanocortin activation of nucleus of the solitary tract avoids anorectic tachyphylaxis and induces prolonged weight loss

2007 ◽  
Vol 293 (1) ◽  
pp. E252-E258 ◽  
Author(s):  
Gang Li ◽  
Yi Zhang ◽  
Enda Rodrigues ◽  
DongHang Zheng ◽  
Michael Matheny ◽  
...  
Keyword(s):  
Body Weight ◽  
Brain Stem ◽  
Viral Vector ◽  
Mrna Levels ◽  
Solitary Tract ◽  
Related Protein ◽  
Melanocyte Stimulating Hormone ◽  
Brown Adipose ◽  
Agouti Related Protein ◽  
The Brain

To examine the role of the brain stem melanocortin system in long-term energy regulation, we assessed the effects of overproduction of proopiomelanocortin (POMC) in the caudal brain stem of F344xBN rats with adult-onset obesity. Recombinant adeno-associated viral vector encoding POMC gene was delivered to the nucleus of solitary tract (NTS) in the hindbrain, and food intake, body weight, glucose and fat metabolism, brown adipose tissue thermogenesis, and mRNA levels of neuropeptides and melanocortin receptors were assessed. POMC delivery resulted in sustained reduction in food intake and body weight over 42 days and improved insulin sensitivity. At death, in recombinant adeno-associated viral vector-POMC-treated rats vs. control rats, α-melanocyte-stimulating hormone in NTS increased nearly 21-fold, whereas hypothalamic α-melanocyte-stimulating hormone remained unchanged. Visceral adiposity decreased by 37%; tissue triglyeride content diminished by 26% and 47% in liver and muscle, respectively; serum triglyeride and nonesterified fatty acids were reduced by 35% and 34%, respectively; phosphorylation of acetyl-CoA carboxylase was elevated by 63% in soleus muscle; brown adipose tissue uncoupling protein 1 increased by 30%; and melanocortin 3 receptor expression declined by 60%, whereas neuropeptide Y, agouti-related protein, and MC4 receptor mRNA levels were unchanged in the NTS. In conclusion, POMC overexpression in the NTS produces a characteristic unabated hypophagia that is uniquely different from the anorexic tachyphylaxis following POMC overexpression in the hypothalamus. The sustained anorectic response may result from absence of compensatory elements in the NTS, such as increased agouti-related protein expression, suggesting melanocortin activation of the brain stem may be a viable strategy to alleviate obesity.

Fos-like immunoreactivity in the brain stem following oral quinine stimulation in decerebrate rats

1999 ◽  
Vol 277 (2) ◽  
pp. R384-R394 ◽  
Author(s):  
Joseph B. Travers ◽  
Kevin Urbanek ◽  
Harvey J. Grill
Keyword(s):  
Brain Stem ◽  
Control Group ◽  
Solitary Tract ◽  
Intact Group ◽  
Sensorimotor Processing ◽  
Unstimulated Control ◽  
Rejection Response ◽  
Lower Brain Stem ◽  
The Brain ◽  
Intact Rats

The present study compared the distribution of Fos-like immunoreactivity (FLI) following intraoral stimulation with quinine monohydrochloride (QHCl) in awake intact rats to the pattern obtained in chronic supracollicular decerebrate (CD) rats. Because the behavioral rejection response to QHCl is evident in the CD rat, it was hypothesized that the pattern of FLI in the lower brain stem should be similar in both groups. Overall, the distribution of FLI in the brain stem was quite similar in both intact and CD groups, and QHCl stimulation increased FLI in the rostral (gustatory) nucleus of the solitary tract, the parabrachial nucleus (PBN), and the lateral reticular formation (RF) compared with an unstimulated control group. The CD group differed from the intact group, however, with a trend toward less FLI in the RF and a shift in the pattern of label away from the external subdivision of the PBN. CD rats also had increased FLI in the caudal nucleus of the solitary tract, with or without intraoral infusions. The distribution of QHCl-induced FLI in the brain stem of intact rats thus indicates both local sensorimotor processing as well as the influence of forebrain structures.

scholarly journals Comparison of baroreceptive to other afferent synaptic transmission to the medial solitary tract nucleus

2008 ◽  
Vol 295 (5) ◽  
pp. H2032-H2042 ◽  
Author(s):  
Michael C. Andresen ◽  
James H. Peters
Keyword(s):  
Synaptic Transmission ◽  
Brain Stem ◽  
Glutamate Release ◽  
Second Order ◽  
Visceral Afferents ◽  
Solitary Tract Nucleus ◽  
Failure Rates ◽  
Solitary Tract ◽  
Frequency Dependent ◽  
Aortic Depressor Nerve

Cranial nerve visceral afferents enter the brain stem to synapse on neurons within the solitary tract nucleus (NTS). The broad heterogeneity of both visceral afferents and NTS neurons makes understanding afferent synaptic transmission particularly challenging. To study a specific subgroup of second-order neurons in medial NTS, we anterogradely labeled arterial baroreceptor afferents of the aortic depressor nerve (ADN) with lipophilic fluorescent tracer (i.e., ADN+) and measured synaptic responses to solitary tract (ST) activation recorded from dye-identified neurons in medial NTS in horizontal brain stem slices. Every ADN+ NTS neuron received constant-latency ST-evoked excitatory postsynaptic currents (EPSCs) (jitter <192 μs, SD of latency). Stimulus-recruitment profiles showed single thresholds and no suprathreshold recruitment, findings consistent with EPSCs arising from a single, branched afferent axon. Frequency-dependent depression of ADN+ EPSCs averaged ∼70% for five shocks at 50 Hz, but single-shock failure rates did not exceed 4%. Whether adjacent ADN− or those from unlabeled animals, other second-order NTS neurons (jitters <200 μs) had ST transmission properties indistinguishable from ADN+. Capsaicin (CAP; 100 nM) blocked ST transmission in some neurons. CAP-sensitive ST-EPSCs were smaller and failed over five times more frequently than CAP-resistant responses, whether ADN+ or from unlabeled animals. Variance-mean analysis of ST-EPSCs suggested uniformly high probabilities for quantal glutamate release across second-order neurons. While amplitude differences may reflect different numbers of contacts, higher frequency-dependent failure rates in CAP-sensitive ST-EPSCs may arise from subtype-specific differences in afferent axon properties. Thus afferent transmission within medial NTS differed by axon class (e.g., CAP sensitive) but was indistinguishable by source of axon (e.g., baroreceptor vs. nonbaroreceptor).

scholarly journals Immunohistochemical Localization of DARPP-32 in the Brain of Two Lungfishes: Further Assessment of Its Relationship with the Dopaminergic System

2017 ◽  
Vol 90 (4) ◽  
pp. 289-310 ◽  
Author(s):  
Jesús M. López ◽  
Ruth Morona ◽  
Agustín González
Keyword(s):  
Suprachiasmatic Nucleus ◽  
Brain Regions ◽  
D1 Receptor ◽  
Lateral Septum ◽  
Torus Semicircularis ◽  
Solitary Tract Nucleus ◽  
Solitary Tract ◽  
Hypothalamic Region ◽  
Extant Species ◽  
The Brain

The distribution of DARPP-32 (a phosphoprotein related to the dopamine D1 receptor) has been widely used as a means to clarify the brain regions with dopaminoceptive cells, primarily in representative species of tetrapods. The relationship between dopaminergic and dopaminoceptive elements is frequently analyzed using the catecholamine marker tyrosine hydroxylase (TH). In the present study, by means of combined immunohistochemistry, we have analyzed these relationships in lungfishes, the only group of sarcopterygian fishes represented by 6 extant species that are the phylogenetically closest living relatives of tetrapods. We used the Australian lungfish Neoceratodus forsteri and the African lungfish Protopterus dolloi. The DARPP-32 antibody yields a distinct and consistent pattern of neuronal staining in brain areas that, in general, coincide with areas that are densely innervated by TH-immunoreactive fibers. The striatum, thalamus, optic tectum, and torus semicircularis contain intensely DARPP-32-immunoreactive cell bodies and fibers. Cells are also located in the olfactory bulbs, amygdaloid complex, lateral septum, pallidum, preoptic area, suprachiasmatic nucleus, tuberal hypothalamic region, rostral rhombencephalic reticular formation, superior raphe nucleus, octavolateral area, solitary tract nucleus, and spinal cord. Remarkably, DARPP-32-immunoreactive fibers originating in the striatum reach the region of the dopaminergic cells in the mesencephalic tegmentum and represent a well-established striatonigral pathway in lungfishes. Double immunolabeling reveals that DARPP-32 is present in neurons that most likely receive TH input, but it is absent from the catecholaminergic neurons themselves, with the only exception of a few cells in the suprachiasmatic nucleus of Neoceratodus and the solitary tract nucleus of Protopterus. In addition, some species differences exist in the localization of DARPP-32 cells in the pallium, lateral amygdala, thalamus, prethalamus, and octavolateral area. In general, the present study demonstrates that the distribution pattern of DARPP-32, and its relationship with TH, is largely comparable to those reported for tetrapods, highlighting a shared situation among all sarcopterygians.

Permeability of the microcirculation in area postrema of rat

1988 ◽  
Vol 46 ◽  
pp. 348-349
Author(s):  
Shams M. Ghoneim ◽  
Frank M. Faraci ◽  
Gary L. Baumbach
Keyword(s):  
Brain Stem ◽  
Area Postrema ◽  
Upper Body ◽  
Sprague Dawley ◽  
Sodium Cacodylate ◽  
Acute Hypertension ◽  
Sprague Dawley Rats ◽  
Ultrastructural Characteristics ◽  
The Brain ◽  
Adjacent Brain

The area postrema is a circumventricular organ in the brain stem and is one of the regions in the brain that lacks a fully functional blood-brain barrier. Recently, we found that disruption of the microcirculation during acute hypertension is greater in area postrema than in the adjacent brain stem. In contrast, hyperosmolar disruption of the microcirculation is greater in brain stem. The objective of this study was to compare ultrastructural characteristics of the microcirculation in area postrema and adjacent brain stem.We studied 5 Sprague-Dawley rats. Horseradish peroxidase was injected intravenously and allowed to circulate for 1, 5 or 15 minutes. Following perfusion of the upper body with 2.25% glutaraldehyde in 0.1 M sodium cacodylate, the brain stem was removed, embedded in agar, and chopped into 50-70 μm sections with a TC-Sorvall tissue chopper. Sections of brain stem were incubated for 1 hour in a solution of 3,3' diaminobenzidine tetrahydrochloride (0.05%) in 0.05M Tris buffer with 1% H2O2.

Surgical Approaches to the Brain Stem

1993 ◽  
Vol 4 (3) ◽  
pp. 457-468 ◽  
Author(s):  
Dennis Y. Wen ◽  
Roberto C. Heros
Keyword(s):  
Brain Stem ◽  
Surgical Approaches ◽  
The Brain
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