Effects of Electrical Stimulation of the Chorda Tympani Nerve on Taste Responses in the Nucleus of the Solitary Tract

2002 ◽  
Vol 88 (5) ◽  
pp. 2477-2489 ◽  
Author(s):  
Christian H. Lemon ◽  
Patricia M. Di Lorenzo
Keyword(s):  
Electrical Stimulation ◽  
Temporal Organization ◽  
Synaptic Activity ◽  
Inhibitory Influence ◽  
Chorda Tympani ◽  
Solitary Tract ◽  
Chorda Tympani Nerve ◽  
Paired Pulse ◽  
Pulse Stimulation ◽  
Stimulation Of

Despite evidence for an abundance of inhibitory synaptic processes within the taste-responsive portion of the brain stem, little is known about how these processes are activated or modulated. In this context, this study tested the hypothesis that activation of the chorda tympani nerve (CT) invokes inhibition that influences gustatory neural information processing in the rostral nucleus of the solitary tract (NTS). Stimulating electrodes were implanted in the middle ear of urethane-anesthetized rats to enable the passage of current across the CT. Electrophysiological responses to sucrose, NaCl, HCl, and quinine were recorded from single NTS neurons both individually and immediately following tetanic electrical stimulation of the CT. Additionally, NTS field responses to paired pulse stimulation of the CT were recorded. Electrical pulses delivered to the CT were found to produce a compound action potential with four components. Taste-responsive units in the NTS showed tetanus-evoked responses that varied in latency and strength. Those cells that showed strong, short latency responses to CT stimulation showed large magnitude responses to NaCl and were relatively narrowly tuned. Units with longer latencies generally responded more broadly to taste stimuli and with lower response magnitudes. Following tetanus, taste responses in 20 (43%) of the 46 units were reversibly altered in a stimulus-selective manner. Taste responses in 18 units were both enhanced and attenuated following tetanic stimulation, although attenuation was much more common. Additionally, tetanus was found to affect the temporal organization of spikes within taste responses to one stimulus in seven units (15%), four of which also showed changes in response magnitude to a different stimulus following tetanus. The influence of tetanus on taste responses was shown to be reliable and repeatable in neurons from which stimulus trials were recorded more than once. Across all units, responses to quinine were most dramatically and frequently attenuated following tetanus, while those to NaCl were least susceptible to change. NTS field responses evoked by paired pulse stimulation of the CT suggested that the initial pulse evoked an inhibitory influence in the NTS that decayed and returned to baseline by 2 s. These data are consistent with the idea that afferent input to the NTS normally activates inhibitory synaptic activity. As with other sensory systems, such inhibition may serve to facilitate contrast in the neural representation of different stimulus qualities.

Dental Afferents Project onto Gustatory Neurons in the Nucleus of the Solitary Tract

2011 ◽  
Vol 91 (2) ◽  
pp. 215-220 ◽  
Author(s):  
A. Braud ◽  
A. Vandenbeuch ◽  
F. Zerari-Mailly ◽  
Y. Boucher
Keyword(s):  
Electrical Stimulation ◽  
Inferior Alveolar Nerve ◽  
Chorda Tympani ◽  
Solitary Tract ◽  
Tracer Injection ◽  
Physiological Basis ◽  
Before And After ◽  
Gustatory Neurons ◽  
Stimulation Of

The aim of this study was to investigate the inferior alveolar nerve (IAN) and chorda tympani (CT) projections onto gustatory neurons of the nucleus of the solitary tract (NST) in the rat by immunochemical and electrophysiological techniques. IAN afferents were retrogradely labeled. NST neurons were labeled either by retrograde tracer injection into the parabrachial nucleus (PBN) or by c-Fos mapping after CT activation. NST neurons responding to tastant stimulation were recorded in vivo before and after electrical stimulation of the IAN. Results from the immunolabeling approach showed IAN boutons “en passant” apposed to retrogradely labeled neurons from PBN and to CT-activated neurons in the NST. Recordings of single NST neurons showed that the electrical stimulation of the IAN significantly decreased CT gustatory responses. Analysis of these data provides an anatomical and physiological basis to support trigeminal dental and gustatory interactions within the brainstem.

The parasympathetic vasodilator fibers in the trigeminal portion of the distal lingual nerve in the cat tongue

1994 ◽  
Vol 266 (5) ◽  
pp. R1517-R1522 ◽  
Author(s):  
H. Izumi ◽  
K. Karita
Keyword(s):  
Blood Flow ◽  
Electrical Stimulation ◽  
Facial Nerve ◽  
Vagus Nerve ◽  
Major Part ◽  
Inferior Alveolar Nerve ◽  
Lingual Nerve ◽  
Chorda Tympani ◽  
Chorda Tympani Nerve ◽  
Stimulation Of

Electrical stimulation of the peripheral and central cut ends of the chorda tympani nerve (CTN) caused an increase in ipsilateral tongue blood flow in anesthetized cats. Both blood flow increases were markedly reduced by pretreatment with the autonomic ganglionic blocker hexamethonium (1.0 mg/kg). Electrical stimulation of the central cut ends of the CTN, inferior alveolar nerve, and vagus nerve as well as of the upper buccal gingiva also caused the vasodilator responses in the sympathectomized cat tongue. These vasodilatations were notably reduced by hexamethonium pretreatment, and were almost completely abolished by the section of the distal lingual nerve (DLN) and the lingual nerve proper but not by section of the CTN. The present data suggest that the parasympathetic vasodilator fibers in the CTN are not involved in somatoautonomic reflex vasodilatation in the cat tongue and that the major part of the somatoautonomic reflex vasodilator response is mediated by parasympathetic fibers running together with the trigeminal portion of the DLN as vasodilator fibers in the cat tongue. This also implies that there are two groups of parasympathetic vasodilator fibers, that is, one originates from the CTN (the facial nerve) and other from the trigeminal portion of the DLN (probably via the glossopharyngeal nerve).

Effect of Electrical Stimulation of the Nucleus of the Solitary Tract on Electroencephalographic Spectral Power and the Sleep–Wake Cycle in Freely Moving Cats

2017 ◽  
Vol 10 (1) ◽  
pp. 116-125 ◽  
Author(s):  
D. Martínez-Vargas ◽  
A. Valdés-Cruz ◽  
V.M. Magdaleno-Madrigal ◽  
R. Fernández-Mas ◽  
S. Almazán-Alvarado
Keyword(s):  
Electrical Stimulation ◽  
Spectral Power ◽  
Solitary Tract ◽  
Freely Moving ◽  
Freely Moving Cats ◽  
Stimulation Of

Paired-pulse stimulation of an electric-hydraulic pump used to replace the mammalian heart

1968 ◽  
Vol 35 (1) ◽  
pp. 41-47
Author(s):  
S. D. Moulopoulos ◽  
M. J. Crosby ◽  
Y. Nose ◽  
W. J. Kolff
Keyword(s):  
Hydraulic Pump ◽  
Paired Pulse ◽  
Mammalian Heart ◽  
Pulse Stimulation ◽  
Stimulation Of

Salivary secretion in cat submandibular gland mediated by chorda tympani afferents

1995 ◽  
Vol 268 (2) ◽  
pp. R438-R444 ◽  
Author(s):  
H. Izumi ◽  
K. Karita
Keyword(s):  
Submandibular Gland ◽  
Salivary Secretion ◽  
Lingual Nerve ◽  
Prior Treatment ◽  
Chorda Tympani ◽  
Chorda Tympani Nerve ◽  
Autonomic Ganglion ◽  
Blood Flow Increase ◽  
A Site ◽  
Stimulation Of

The aim of the present study was to investigate whether the afferent traffic from the tongue mediated only via the chorda tympani nerve (CTN) can still elicit reflex salivary and vasodilator responses in the cat submandibular gland (SMG) after section of the lingual nerve proper (LNP). Electrical stimulation of the chorda lingual nerve (CLN) at a site approximately 5 mm distal to the intersection of the CLN and the SMG duct elicited salivary and vasodilator responses in the SMG in sympathectomized cats. Both responses were unaffected by section of the LNP. The optimal frequency of CLN stimulation for submandibular salivation and vasodilation was 20 Hz, regardless of whether the LNP had been cut. Prior treatment with the autonomic ganglion blocker hexamethonium (10 mg/kg iv) virtually abolished the salivation and the blood flow increase in SMG. Prior treatment with scopolamine (0.1 mg/kg iv) almost abolished the salivary secretions but had no effect on the vasodilator responses in the SMG elicited by CLN stimulation after LNP section. The mechanism underlying the reflex submandibular salivation mediated by chorda tympani afferents appears to involve parasympathetic muscarinic receptors, but the mechanism for the vasodilator response has yet to be established. These results indicate that afferent traffic passing through the CTN on CLN stimulation is importantly involved in the parasympathetic reflex secretory and vasodilator responses in the cat SMG.

Integration of cornea and cardiorespiratory afferents in the nucleus of the solitary tract of the rat

2002 ◽  
Vol 282 (4) ◽  
pp. H1278-H1287 ◽  
Author(s):  
Pedro Boscan ◽  
Julian F. R. Paton
Keyword(s):  
Electrical Stimulation ◽  
Solitary Tract ◽  
Peripheral Chemoreceptor ◽  
Single Unit Recordings ◽  
Degree Of Convergence ◽  
High Degree ◽  
Working Heart ◽  
Stimulation Of ◽  
Nerve Discharge

We determined the activity of neurons within the nucleus of the solitary tract (NTS) after stimulation of the cornea and assessed whether this input affected the processing of baroreceptor and peripheral chemoreceptor inputs. In an in situ, unanesthetized decerebrate working heart-brain stem preparation of the rat, noxious mechanical or electrical stimulation was applied to the cornea, and extracellular single unit recordings were made from NTS neurons. Cornea nociceptor stimulation evoked bradycardia and an increase in the cycle length of the phrenic nerve discharge. Of 90 NTS neurons with ongoing activity, corneal stimulation excited 51 and depressed 39. There was a high degree of convergence to these NTS neurons from either baroreceptors or chemoreceptors. The excitatory synaptic response in 12 of 19 baroreceptive and 10 of 15 chemoreceptive neurons was attenuated significantly during concomitant electrical stimulation of the cornea. This inhibition was GABAA receptor mediated, being blocked by pressure ejection of bicuculline. Thus the NTS integrates information from corneal receptors, some of which converges onto neurons mediating reflexes from baroreceptors and chemoreceptors to inhibit these inputs.

scholarly journals Characterization of Prejunctional Muscarinic Receptors: Effects on the Release of VIP and Functional Responses and Receptor Expression in the Ovine Submandibular Gland

2009 ◽  
Vol 2009 ◽  
pp. 1-6
Author(s):  
Anders T. Ryberg ◽  
Ondrej Soukup ◽  
Gunnar Tobin
Keyword(s):  
Electrical Stimulation ◽  
Submandibular Gland ◽  
Muscarinic Receptor ◽  
Muscarinic Receptors ◽  
Receptor Expression ◽  
Receptor Subtypes ◽  
Chorda Tympani Nerve ◽  
Functional Responses ◽  
Stimulation Of

In the in vivo experiments on anaesthetized sheep, it was presently examined whether muscarinic receptor antagonists with diverse selectivity affect the release of VIP in response to electrical stimulation of the parasympathetic chorda tympanic nerve differently, and if the changes in the release could be associated to altered secretory and vasodilator responses. The location of the muscarinic receptor subtypes was examined also. In the experiments, blood was collected out of the submandibular venous drainage before and during electrical stimulation of chorda tympani nerve in the absence and presence either of pirenzepine or methoctramine. While metchoctramine increased the output of protein, pirenzepine inhibited flow of saliva and increased protein output, vasodilatation, and VIP output. In morphological examinations, the inhibitory muscarinic M4 receptor occurred interacinarily in the gland. It is concluded that prejunctional muscarinic receptors, most likely of the M4 subtype, exert inhibitory modulation of the parasympathetic release of VIP in the ovine submandibular gland.

Excitation of lumbar motoneurons by the medial longitudinal fasciculus in the in vitro brain stem spinal cord preparation of the neonatal rat

1993 ◽  
Vol 70 (6) ◽  
pp. 2241-2250 ◽  
Author(s):  
M. K. Floeter ◽  
A. Lev-Tov
Keyword(s):  
Spinal Cord ◽  
Brain Stem ◽  
Short Latency ◽  
Medial Longitudinal Fasciculus ◽  
Paired Pulse ◽  
Long Latency ◽  
The Brain ◽  
Pulse Stimulation ◽  
Stimulation Of

1. The excitation of lumbar motoneurons by reticulospinal axons traveling in the medial longitudinal fasciculus (MLF) was investigated in the newborn rat using intracellular recordings from lumbar motoneurons in an in vitro preparation of the brain stem and spinal cord. The tracer DiI (1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine) was introduced into the MLF of 6-day-old littermate rats that had been fixed with paraformaldehyde to evaluate the anatomic extent of this developing pathway. 2. Fibers labeled from the MLF by DiI were present in the cervical ventral and lateral white matter and a smaller number of labeled fibers extended to the lumbar enlargement. Patches of sparse terminal labeling were seen in the lumbar ventral gray. 3. In the in vitro preparation of the brain stem and spinal cord, MLF stimulation excited motoneurons through long-latency pathways in most motoneurons and through both short-(< 40 ms) and long-latency connections in 16 of 40 motoneurons studied. Short- and longer-latency components of the excitatory response were evaluated using mephenesin to reduce activity in polysynaptic pathways. 4. Paired-pulse stimulation of the MLF revealed a modest temporal facilitation of the short-latency excitatory postsynaptic potential (EPSP) at short interstimulus intervals (20–200 ms). Trains of stimulation at longer interstimulus intervals (1–30 s) resulted in a depression of EPSP amplitude. The time course of the synaptic depression was compared with that found in EPSPs resulting from paired-pulse stimulation of the dorsal root and found to be comparable. 5. The short-latency MLF EPSP was reversibly blocked by 6-cyano-7-nitroquinoxaline (CNQX), an antagonist of non-N-methyl-D-aspartate glutamate receptors, with a small CNQX-resistant component. Longer-latency components of the MLF EPSP were also blocked by CNQX, and some late components of the PSP were sensitive to strychnine. MLF activation of multiple polysynaptic pathways in the spinal cord is discussed.

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