Electrophysiological Studies of Target-Identified Vagal Afferent Cell Bodies

2005 ◽  
pp. 101-120
Author(s):  
Danny Weinreich
Keyword(s):  
Electrophysiological Studies ◽  
Vagal Afferent

Electrical physiological evidence for highand low-affinity vagal CCK-A receptors

1999 ◽  
Vol 277 (2) ◽  
pp. G469-G477 ◽  
Author(s):  
Ying Li ◽  
Jinxia Zhu ◽  
Chung Owyang
Keyword(s):  
Receptor Antagonist ◽  
Receptor Field ◽  
Cck Receptors ◽  
Physiological Conditions ◽  
Nodose Ganglia ◽  
Afferent Fibers ◽  
Electrophysiological Studies ◽  
Vagal Afferent ◽  
Cck Receptor Antagonist ◽  
Afferent Response

We have demonstrated that under physiological conditions CCK acts through vagal high-affinity CCK-A receptors to mediate pancreatic secretion. In this study, we evaluated the vagal afferent response to endogenous CCK in rats and defined the CCK-receptor affinity states and the vagal-receptive field responsive to CCK stimulation using electrophysiological studies. Experiments were performed on anesthetized rats prepared with bile-pancreatic fistula. Plasma CCK levels were elevated by diverting bile-pancreatic juice (BPJ). The single-unit discharge of sensory neurons supplying the gastrointestinal tract was recorded from the nodose ganglia. All units studied were either silent or they had a very low resting discharge frequency. Thirty-two single units were studied extensively; seven were shown to be stimulated by diversion of BPJ (2.6 ± 2 impulses/min at basal to 40 ± 12 impulses/min after diversion). Acute subdiaphragmatic vagotomy or perivagal capsaicin treatment abolished the response. The CCK-A-receptor antagonist CR-1409, but not the CCK-B antagonist L-365260, blocked the vagal response to endogenous CCK stimulation. Infusion of the low-affinity CCK-receptor antagonist CCK-JMV-180 completely blocked the vagal afferent response to the diversion of BPJ in three of seven rats tested but had no effect on the response in the remaining four. In a separate study, we demonstrated that gastric, celiac, or hepatic branch vagotomy abolished the response in different subgroups of neurons. In conclusion, under physiological conditions, CCK acts on both high- and low-affinity CCK-A receptors present on distinct vagal afferent fibers. The vagal CCK-receptor field includes the regions innervated by the gastric, celiac, and hepatic vagal branches. This study provides electrophysiological evidence that vagal CCK receptors are present on the vagal gastric, celiac, and hepatic branches and may occur in high- and low-affinity states.

scholarly journals Peripheral Interaction of Ghrelin with Cholecystokinin on Feeding Regulation

Endocrinology ◽  
2005 ◽  
Vol 146 (8) ◽  
pp. 3518-3525 ◽  
Author(s):  
Yukari Date ◽  
Koji Toshinai ◽  
Shuichi Koda ◽  
Mikiya Miyazato ◽  
Takuya Shimbara ◽  
...  
Keyword(s):  
Food Intake ◽  
Arcuate Nucleus ◽  
Gastrointestinal Hormones ◽  
Short Term ◽  
Oletf Rats ◽  
Feeding Regulation ◽  
Electrophysiological Studies ◽  
Hypothalamic Arcuate Nucleus ◽  
Vagal Afferent ◽  
Long Evans

Abstract Ghrelin and cholecystokinin (CCK) are gastrointestinal hormones regulating feeding. Both transmitted via the vagal afferent, ghrelin elicits starvation signals, whereas CCK induces satiety signals. We investigated the interaction between ghrelin and CCK functioning in short-term regulation of feeding in Otsuka Long-Evans Tokushima fatty (OLETF) rats, which have a disrupted CCK type A receptor (CCK-AR), and their lean littermates, Long-Evans Tokushima Otsuka (LETO) rats. Intravenous administration of ghrelin increased 2-h food intake in both OLETF and LETO rats. Because OLETF rats are CCK insensitive, iv-administered CCK decreased 2-h food intake in LETO, but not in OLETF, rats. Although preadministration of CCK to LETO rats blocked food intake induced by ghrelin, CCK preadministration to OLETF rats did not affect ghrelin-induced food intake. Conversely, preadministration of ghrelin to LETO rats blocked feeding reductions induced by CCK. In electrophysiological studies, once gastric vagal afferent discharges were altered by ghrelin or CCK administration, they could not be additionally affected by serial administrations of either CCK or ghrelin, respectively. The induction of Fos expression in the hypothalamic arcuate nucleus by ghrelin was also attenuated by CCK preadministration. Using immunohistochemistry, we also demonstrated the colocalization of GH secretagogue receptor (GHS-R), the cellular receptor for ghrelin, with CCK-AR in vagal afferent neurons. These results indicate that the vagus nerve plays a crucial role in determining peripheral energy balance. The efficiency of ghrelin and CCK signal transduction may depend on the balance of their respective plasma concentration and/or on interactions between GHS-R and CCK-AR.

The Involuntary Capture of Attention by Sound

2010 ◽  
Vol 57 (1) ◽  
pp. 68-76 ◽  
Author(s):  
Fabrice B. R. Parmentier ◽  
Pilar Andrés
Keyword(s):  
Older Adults ◽  
Mismatch Negativity ◽  
Visual Task ◽  
The Novel ◽  
Auditory Oddball ◽  
Current Trial ◽  
Electrophysiological Responses ◽  
Electrophysiological Studies ◽  
The Cross ◽  
Task Sets

The presentation of auditory oddball stimuli (novels) among otherwise repeated sounds (standards) triggers a well-identified chain of electrophysiological responses: The detection of acoustic change (mismatch negativity), the involuntary orientation of attention to (P3a) and its reorientation from the novel. Behaviorally, novels reduce performance in an unrelated visual task (novelty distraction). Past studies of the cross-modal capture of attention by acoustic novelty have typically discarded from their analysis the data from the standard trials immediately following a novel, despite some evidence in mono-modal oddball tasks of distraction extending beyond the presentation of deviants/novels (postnovelty distraction). The present study measured novelty and postnovelty distraction and examined the hypothesis that both types of distraction may be underpinned by common frontally-related processes by comparing young and older adults. Our data establish that novels delayed responses not only on the current trial and but also on the subsequent standard trial. Both of these effects increased with age. We argue that both types of distraction relate to the reconfiguration of task-sets and discuss this contention in relation to recent electrophysiological studies.

The Neurobiology of Reading Differs for Deaf and Hearing Adults

2020 ◽  
pp. 346-359
Author(s):  
Karen Emmorey
Keyword(s):  
Semantic Processing ◽  
Event Related Potentials ◽  
Coarse Grained ◽  
Reading Success ◽  
Deaf Readers ◽  
Electrophysiological Studies ◽  
Deaf Adults ◽  
Related Potentials ◽  
Reading System ◽  
New Evidence

Recent neuroimaging and electrophysiological studies reveal how the reading system successfully adapts when phonological codes are relatively coarse-grained due to reduced auditory input during development. New evidence suggests that the optimal end-state for the reading system may differ for deaf versus hearing adults and indicates that certain neural patterns that are maladaptive for hearing readers may be beneficial for deaf readers. This chapter focuses on deaf adults who are signers and have achieved reading success. Although the left-hemisphere-dominant reading circuit is largely similar in both deaf and hearing individuals, skilled deaf readers exhibit a more bilateral neural response to written words and sentences than their hearing peers, as measured by event-related potentials and functional magnetic resonance imaging. Skilled deaf readers may also rely more on neural regions involved in semantic processing than hearing readers do. Overall, emerging evidence indicates that the neural markers for reading skill may differ for deaf and hearing adults.

scholarly journals Canine Myocytes Represent a Good Model for Human Ventricular Cells Regarding Their Electrophysiological Properties

2021 ◽  
Vol 14 (8) ◽  
pp. 748
Author(s):  
Péter P. Nánási ◽  
Balázs Horváth ◽  
Fábián Tar ◽  
János Almássy ◽  
Norbert Szentandrássy ◽  
...  
Keyword(s):  
Action Potential ◽  
Time Course ◽  
Laboratory Animals ◽  
Delayed Rectifier ◽  
Ion Currents ◽  
Human Cardiomyocytes ◽  
Ventricular Cells ◽  
Repolarization Reserve ◽  
Electrophysiological Studies ◽  
K Current

Due to the limited availability of healthy human ventricular tissues, the most suitable animal model has to be applied for electrophysiological and pharmacological studies. This can be best identified by studying the properties of ion currents shaping the action potential in the frequently used laboratory animals, such as dogs, rabbits, guinea pigs, or rats, and comparing them to those of human cardiomyocytes. The authors of this article with the experience of three decades of electrophysiological studies, performed in mammalian and human ventricular tissues and isolated cardiomyocytes, summarize their results obtained regarding the major canine and human cardiac ion currents. Accordingly, L-type Ca2+ current (ICa), late Na+ current (INa-late), rapid and slow components of the delayed rectifier K+ current (IKr and IKs, respectively), inward rectifier K+ current (IK1), transient outward K+ current (Ito1), and Na+/Ca2+ exchange current (INCX) were characterized and compared. Importantly, many of these measurements were performed using the action potential voltage clamp technique allowing for visualization of the actual current profiles flowing during the ventricular action potential. Densities and shapes of these ion currents, as well as the action potential configuration, were similar in human and canine ventricular cells, except for the density of IK1 and the recovery kinetics of Ito. IK1 displayed a largely four-fold larger density in canine than human myocytes, and Ito recovery from inactivation displayed a somewhat different time course in the two species. On the basis of these results, it is concluded that canine ventricular cells represent a reasonably good model for human myocytes for electrophysiological studies, however, it must be borne in mind that due to their stronger IK1, the repolarization reserve is more pronounced in canine cells, and moderate differences in the frequency-dependent repolarization patterns can also be anticipated.

scholarly journals Morphological Characterization of the Antennal Sensilla of the Afrotropical Sand Fly, Phlebotomus duboscqi (Diptera: Psychodidae)

2020 ◽  
Author(s):  
Ana Cristina Bahia ◽  
Ana Beatriz F Barletta ◽  
Luciana Conceição Pinto ◽  
Alessandra S Orfanó ◽  
Rafael Nacif-Pimenta ◽  
...  
Keyword(s):  
Morphological Characters ◽  
Morphological Characterization ◽  
Sand Fly ◽  
Antennal Sensilla ◽  
Olfactory Sensilla ◽  
Zoonotic Cutaneous Leishmaniasis ◽  
Electrophysiological Studies ◽  
Phlebotomus Duboscqi ◽  
Well Differentiated ◽  
Function Number

Abstract We investigated by scanning electron microscopy the morphology, distribution, and abundance of antennal sensilla of females Phlebotomus duboscqi sand fly, an important vector of zoonotic cutaneous leishmaniasis at Afrotropical region. Thirteen well-differentiated sensilla were identified, among six types of cuticular sensilla. The probable function of these sensillary types is discussed in relation to their external structure and distribution. Five sensillary types were classified as olfactory sensilla, as they have specific morphological characters of sensilla with this function. Number and distribution of sensilla significantly differed between antennal segments. The results of the present work, besides corroborating in the expansion of the morphological and ultrastructural knowledge of P. duboscqi, can foment future electrophysiological studies for the development of volatile semiochemicals, to be used as attractants in traps for monitoring and selective vector control of this sand fly.

Sign in / Sign up

Export Citation Format

Share Document