Modulation of activity of gustatory neurons in the hamster parabrachial nuclei by electrical stimulation of the ventroposteromedial nucleus of the thalamus

2008 ◽  
Vol 294 (5) ◽  
pp. R1461-R1473 ◽  
Author(s):  
Limin Mao ◽  
Young K. Cho ◽  
Cheng-Shu Li
Keyword(s):  
Electrical Stimulation ◽  
Inhibitory Response ◽  
Projection Neurons ◽  
Efferent Projection ◽  
Electrophysiological Studies ◽  
Parabrachial Nuclei ◽  
Gustatory Information ◽  
Ventroposteromedial Nucleus ◽  
Gustatory Neurons ◽  
Stimulation Of

The parvicellular part of the ventroposteromedial nucleus of the thalamus (VPMpc) is positioned at the key site between the gustatory parabrachial nuclei (PbN) and the gustatory cortex for relaying and processing gustatory information via the thalamocortical pathway. Although neuroanatomical and electrophysiological studies have provided information regarding the gustatory projection from PbN to VPMpc, the exact relationship between PbN and VPMpc, especially the efferent projection involving VPMpc to PbN, is obscure. Here we investigated the reciprocal connection between these two gustatory relays in urethane-anesthetized hamsters. We recorded from 114 taste-responsive neurons in the PbN and examined their responsiveness to electrical stimulation of the VPMpc bilaterally. Stimulation of either or both of the ipsilateral or contralateral VPMpc antidromically activated 109 gustatory PbN neurons. Seventy-two PbN neurons were antidromically activated after stimulation of both sides of the VPMpc, indicating that taste neurons in the PbN project heavily to the bilateral VPMpc. Stimulation of VPMpc also orthodromically activated 110 of PbN neurons, including 106 VPMpc projection neurons. Seventy-eight neurons were orthodromically activated bilaterally. Among orthodromic activations of the PbN cells, the inhibitory response was the dominant response; 106 cells were inhibited, including 10 neurons that were also excited contralaterally, indicating that taste neurons in the PbN are subject to strong inhibitory control from VPMpc. Moreover, stimulation of VPMpc altered taste responses of the neurons in the PbN, indicating that VPMpc modulates taste responses of PbN neurons. These results may provide functional insight of neural circuitry for taste processing and modulation involving these two nuclei.

Efferent projection from the bed nucleus of the stria terminalis suppresses activity of taste-responsive neurons in the hamster parabrachial nuclei

2006 ◽  
Vol 291 (4) ◽  
pp. R914-R926 ◽  
Author(s):  
Cheng-Shu Li ◽  
Young K. Cho
Keyword(s):  
Feeding Behavior ◽  
Electrophysiological Study ◽  
Ingestive Behavior ◽  
Stria Terminalis ◽  
Bed Nucleus ◽  
Descending Modulation ◽  
Efferent Projection ◽  
Neural Substrate ◽  
Parabrachial Nuclei ◽  
Gustatory Neurons

Although the reciprocal projections between the bed nucleus of the stria terminalis (BNST) and the gustatory parabrachial nuclei (PbN) have been demonstrated neuroanatomically, there is no direct evidence showing that the projections from the PbN to the BNST carry taste information or that descending inputs from the BNST to the PbN modulate the activity of PbN gustatory neurons. A recent electrophysiological study has demonstrated that the BNST exerts modulatory influence on taste neurons in the nucleus of the solitary tract (NST), suggesting that the BNST may also modulate the activity of taste neurons in the PbN. In the present study, we recorded from 117 taste-responsive neurons in the PbN and examined their responsiveness to electrical stimulation of the BNST bilaterally. Thirteen neurons (11.1%) were antidromically invaded from the BNST, mostly from the ipsilateral side (12 cells), indicating that a subset of taste neurons in the PbN project their axons to the BNST. The BNST stimulation induced orthodromic responses on most of the PbN neurons: 115 out of 117 (98.3%), including all BNST projection units. This descending modulation on the PbN gustatory neurons was exclusively inhibitory. We also confirmed that activation of this efferent inhibitory projection from the BNST reduces taste responses of PbN neurons in all units tested. The BNST is part of the neural circuits that involve stress-associated feeding behavior. It is also known that brain stem gustatory nuclei, including the PbN, are associated with feeding behavior. Therefore, this neural substrate may be important in the stress-elicited alteration in ingestive behavior.

scholarly journals Canal-Specific Excitation and Inhibition of Frog Second-Order Vestibular Neurons

1997 ◽  
Vol 78 (3) ◽  
pp. 1363-1372 ◽  
Author(s):  
H. Straka ◽  
S. Biesdorf ◽  
N. Dieringer
Keyword(s):  
Electrical Stimulation ◽  
Semicircular Canal ◽  
Second Order ◽  
Projection Neurons ◽  
Postsynaptic Potentials ◽  
Vestibular Neurons ◽  
Inhibitory Postsynaptic Potentials ◽  
Monosynaptic Epsp ◽  
Stimulation Of ◽  
Monosynaptic Excitation

Straka, H., S. Biesdorf, and N. Dieringer. Canal-specific excitation and inhibition of frog second-order vestibular neurons. J. Neurophysiol. 78: 1363–1372, 1997. Second-order vestibular neurons (2°VNs) were identified in the in vitro frog brain by their monosynaptic excitation following electrical stimulation of the ipsilateral VIIIth nerve. Ipsilateral disynaptic inhibitory postsynaptic potentials were revealed by bath application of the glycine antagonist strychnine or of the γ-aminobutyric acid-A (GABAA) antagonist bicuculline. Ipsilateral disynaptic excitatory postsynaptic potentials (EPSPs) were analyzed as well. The functional organization of convergent monosynaptic and disynaptic excitatory and inhibitory inputs onto 2°VNs was studied by separate electrical stimulation of individual semicircular canal nerves on the ipsilateral side. Most 2°VNs (88%) received a monosynaptic EPSP exclusively from one of the three semicircular canal nerves; fewer 2°VNs (10%) were monosynaptically excited from two semicircular canal nerves; and even fewer 2°VNs (2%) were monosynaptically excited from each of the three semicircular canal nerves. Disynaptic EPSPs were present in the majority of 2°VNs (68%) and originated from the same (homonymous) semicircular canal nerve that activated a monosynaptic EPSP in a given neuron (22%), from one or both of the other two (heteronymous) canal nerves (18%), or from all three canal nerves (28%). Homonymous activation of disynaptic EPSPs prevailed (74%) among those 2°VNs that exhibited disynaptic EPSPs. Disynaptic inhibitory postsynaptic potentials (IPSPs) were mediated in 90% of the tested 2°VNs by glycine, in 76% by GABA, and in 62% by GABA as well as by glycine. These IPSPs were activated almost exclusively from the same semicircular canal nerve that evoked the monosynaptic EPSP in a given 2°VN. Our results demonstrate a canal-specific, modular organization of vestibular nerve afferent fiber inputs onto 2°VNs that consists of a monosynaptic excitation from one semicircular canal nerve followed by disynaptic excitatory and inhibitory inputs originating from the homonymous canal nerve. Excitatory and inhibitory second-order (2°) vestibular interneurons are envisaged to form side loops that mediate spatially similar but dynamically different signals to 2° vestibular projection neurons. These feedforward side loops are suited to adjust the dynamic response properties of 2° vestibular projection neurons by facilitating or disfacilitating phasic and tonic input components.

scholarly journals Responses of Neurons in the Insular Cortex to Gustatory, Visceral, and Nociceptive Stimuli in Rats

1998 ◽  
Vol 79 (5) ◽  
pp. 2535-2545 ◽  
Author(s):  
Takamitsu Hanamori ◽  
Takato Kunitake ◽  
Kazuo Kato ◽  
Hiroshi Kannan
Keyword(s):  
Electrical Stimulation ◽  
Intravenous Injection ◽  
Anterior Commissure ◽  
Insular Cortex ◽  
Inhibitory Response ◽  
Inhibitory Neurons ◽  
Excitatory Response ◽  
Tail Pinch ◽  
Posterior Tongue ◽  
Stimulation Of

Hanamori, Takamitsu, Takato Kunitake, Kazuo Kato, and Hiroshi Kannan. Responses of neurons in the insular cortex to gustatory, visceral, and nociceptive stimuli in rats. J. Neurophysiol. 79: 2535–2545, 1998. Extracellular unit responses to baroreceptor and chemoreceptor stimulation, gustatory stimulation of the posterior tongue, electrical stimulation of the superior laryngeal (SL) nerve, and tail pinch were recorded from the insular cortex of anesthetized and paralyzed rats. Forty-three neurons identified responded to stimulation by at least one of the stimuli used in the present study. Of the 43 neurons, 33 responded to tail pinch, and the remaining 10 had no response; 18 showed an excitatory response, and 15 showed an inhibitory response. Of the 43 neurons, 35 responded to electrical stimulation of the SL nerve; 27 showed an excitatory response, and 8 showed an inhibitory response. Of the 20 neurons that responded to baroreceptor stimulation by an intravenous injection of methoxamine hydrochloride (Mex), 11 were excitatory and 9 were inhibitory. Twenty-seven neurons were responsive to an intravenous injection of sodium nitroprusside (SNP); 10 were excitatory and 17 were inhibitory. Ten neurons were excited and 16 neurons were inhibited by arterial chemoreceptor stimulation by an intravenous injection of sodium cyanide (NaCN). Twenty-six neurons were responsive to at least one of the gustatory stimuli (1.0 M NaCl, 30 mM HCl, 30 mM quinine HCl, and 1.0 M sucrose): four to six excitatory neurons and three to nine inhibitory neurons for each stimulus. A large number of the neurons (42/43) received convergent inputs from more than one stimulus among the nine stimuli used in the present study. Most neurons (38/43) were responsive to two or more stimulus groups when the natural stimuli used in the present study are grouped into three, gustatory, visceral, and nociceptive stimuli. The neurons recorded were located in the insular cortex between 2.8 mm anterior and 1.1 mm posterior to the anterior edge of the joining of the anterior commissure (AC); the mean location was 1.0 mm ( n = 43) anterior to the AC. This indicates that most of the neurons identified in the present study were located in the region posterior to the taste area and anterior to the visceral area in the insular cortex. These results indicate that the insular cortex neurons distributing between the taste area and the visceral area receive convergent inputs from baroreceptor, chemoreceptor, gustatory, and nociceptive organs and may have roles in taste aversion or in regulation of visceral responses.

Pontine-evoked inspiratory inhibitions after antagonism of NMDA, GABAA, or glycine receptor

1993 ◽  
Vol 74 (3) ◽  
pp. 1265-1273 ◽  
Author(s):  
L. Ling ◽  
D. R. Karius ◽  
D. F. Speck
Keyword(s):  
Electrical Stimulation ◽  
Glycine Receptor ◽  
Inhibitory Response ◽  
Glycine Receptors ◽  
Onset Latency ◽  
Nerve Activity ◽  
Systemic Injection ◽  
Mk 801 ◽  
Inspiratory Motor ◽  
Stimulation Of

Single-shock stimulation of the pontine respiratory group (PRG) produces a transient short-latency inhibition of inspiratory motor activity. Stimulus trains delivered to the PRG can elicit a premature termination of inspiration. This study examined the involvement of N-methyl-D-aspartate (NMDA), gamma-aminobutyrateA (GABAA), or glycine receptors in these inhibitory responses. Experiments were conducted in decerebrate, paralyzed, and ventilated cats. Control responses to PRG stimulation were obtained from recordings of the left phrenic nerve activity. After systemic injection of MK-801, bicuculline, or strychnine (antagonists to NMDA, GABAA, or glycine receptors, respectively), responses to stimulation were again recorded. Inspiratory termination elicited by the PRG stimulation persisted after antagonism of NMDA, GABAA, or glycine receptors. The onset latency and duration of the transient inhibition were not changed after administration of bicuculline, but MK-801 administration did significantly prolong the duration of the transient inhibition. Strychnine significantly prolonged both the onset latency and the duration. These data suggest that none of the three receptor types is required in the inspiratory termination response elicited by electrical stimulation of the PRG region and that NMDA, GABAA, or glycine receptor-mediated neurotransmission is not solely responsible for the transient inhibitory response. However, the prolonged onset and duration of the transient inhibition after strychnine administration suggest that glycine does normally participate in this response.

Modulation of Parabrachial Taste Neurons by Electrical and Chemical Stimulation of the Lateral Hypothalamus and Amygdala

2005 ◽  
Vol 93 (3) ◽  
pp. 1183-1196 ◽  
Author(s):  
Cheng-Shu Li ◽  
Young K. Cho ◽  
David V. Smith
Keyword(s):  
Citric Acid ◽  
Lateral Hypothalamus ◽  
Ingestive Behavior ◽  
Central Nucleus ◽  
Homocysteic Acid ◽  
Quinine Hydrochloride ◽  
Neural Substrate ◽  
Parabrachial Nuclei ◽  
Gustatory Neurons ◽  
Stimulation Of

The lateral hypothalamus (LH) and the central nucleus of the amygdala (CeA) exert an influence on ingestive behavior and are reciprocally connected to gustatory and viscerosensory areas, including the nucleus of the solitary tract (NST) and the parabrachial nuclei (PbN). We investigated the effects of LH and CeA stimulation on the activity of 101 taste-responsive neurons in the hamster PbN. Eighty three of these neurons were antidromically activated by stimulation of these sites; 57 were antidromically driven by both. Of these 83 neurons, 21 were also orthodromically activated—8 by the CeA and 3 by the LH. Additional neurons were excited ( n = 5) or inhibited ( n = 8) by these forebrain nuclei but not antidromically activated. Taste stimuli were: 0.032 M sucrose, 0.032 M sodium chloride (NaCl), 0.032 M quinine hydrochloride (QHCl), and 0.0032 M citric acid. Among the 34 orthodromically activated neurons, more sucrose-best neurons were excited than inhibited, whereas the opposite occurred for citric-acid- and QHCl-best cells. Neurons inhibited by the forebrain responded significantly more strongly to citric acid and QHCl than cells excited by these sites. The effects of electrical stimulation were mimicked by microinjection of dl-homocysteic acid, indicating that cells at these forebrain sites were responsible for these effects. These data demonstrate that many individual PbN gustatory neurons project to both the LH and CeA and that these areas modulate the gustatory activity of a subset of PbN neurons. This neural substrate is likely involved in the modulation of taste activity by physiological and experiential factors.

scholarly journals Functional territories in primate substantia nigra pars reticulata separately signaling stable and flexible values

2015 ◽  
Vol 113 (6) ◽  
pp. 1681-1696 ◽  
Author(s):  
Masaharu Yasuda ◽  
Okihide Hikosaka
Keyword(s):  
Electrical Stimulation ◽  
Basal Ganglia ◽  
Substantia Nigra ◽  
Signal Transmission ◽  
Inhibitory Response ◽  
Substantia Nigra Pars Reticulata ◽  
Visual Objects ◽  
Direct Input ◽  
Antidromic Response ◽  
Stimulation Of

Gaze is strongly attracted to visual objects that have been associated with rewards. Key to this function is a basal ganglia circuit originating from the caudate nucleus (CD), mediated by the substantia nigra pars reticulata (SNr), and aiming at the superior colliculus (SC). Notably, subregions of CD encode values of visual objects differently: stably by CD tail [CD(T)] vs. flexibly by CD head [CD(H)]. Are the stable and flexible value signals processed separately throughout the CD-SNr-SC circuit? To answer this question, we identified SNr neurons by their inputs from CD and outputs to SC and examined their sensitivity to object values. The direct input from CD was identified by SNr neuron's inhibitory response to electrical stimulation of CD. We found that SNr neurons were separated into two groups: 1) neurons inhibited by CD(T) stimulation, located in the caudal-dorsal-lateral SNr (cdlSNr), and 2) neurons inhibited by CD(H) stimulation, located in the rostral-ventral-medial SNr (rvmSNr). Most of CD(T)-recipient SNr neurons encoded stable values, whereas CD(H)-recipient SNr neurons tended to encode flexible values. The output to SC was identified by SNr neuron's antidromic response to SC stimulation. Among the antidromically activated neurons, many encoded only stable values, while some encoded only flexible values. These results suggest that CD(T)-cdlSNr-SC circuit and CD(H)-rvmSNr-SC circuit transmit stable and flexible value signals, largely separately, to SC. The speed of signal transmission was faster through CD(T)-cdlSNr-SC circuit than through CD(H)-rvmSNr-SC circuit, which may reflect automatic and controlled gaze orienting guided by these circuits.

scholarly journals Descending projections from the nucleus accumbens shell excite activity of taste-responsive neurons in the nucleus of the solitary tract in the hamster

2015 ◽  
Vol 113 (10) ◽  
pp. 3778-3786 ◽  
Author(s):  
Cheng-Shu Li ◽  
Da-Peng Lu ◽  
Young K. Cho
Keyword(s):  
Nucleus Accumbens ◽  
Electrophysiological Study ◽  
Neuronal Firing ◽  
Solitary Tract ◽  
Nucleus Accumbens Shell ◽  
Descending Input ◽  
Parabrachial Nuclei ◽  
Gustatory Neurons ◽  
Stimulation Of

The nucleus of the solitary tract (NST) and the parabrachial nuclei (PbN) are the first and second relays in the rodent central taste pathway. A series of electrophysiological experiments revealed that spontaneous and taste-evoked activities of brain stem gustatory neurons are altered by descending input from multiple forebrain nuclei in the central taste pathway. The nucleus accumbens shell (NAcSh) is a key neural substrate of reward circuitry, but it has not been verified as a classical gustatory nucleus. A recent in vivo electrophysiological study demonstrated that the NAcSh modulates the spontaneous and gustatory activities of hamster pontine taste neurons. In the present study, we investigated whether activation of the NAcSh modulates gustatory responses of the NST neurons. Extracellular single-unit activity was recorded from medullary neurons in urethane-anesthetized hamsters. After taste response was confirmed by delivery of sucrose, NaCl, citric acid, and quinine hydrochloride to the anterior tongue, the NAcSh was stimulated bilaterally with concentric bipolar stimulating electrodes. Stimulation of the ipsilateral and contralateral NAcSh induced firings from 54 and 37 of 90 medullary taste neurons, respectively. Thirty cells were affected bilaterally. No inhibitory responses or antidromic invasion was observed after NAcSh activation. In the subset of taste cells tested, high-frequency electrical stimulation of the NAcSh during taste delivery enhanced taste-evoked neuronal firing. These results demonstrate that two-thirds of the medullary gustatory neurons are under excitatory descending influence from the NAcSh, which is a strong indication of communication between the gustatory pathway and the mesolimbic reward pathway.

Taste Responses of Neurons of the Hamster Solitary Nucleus Are Enhanced by Lateral Hypothalamic Stimulation

2002 ◽  
Vol 87 (4) ◽  
pp. 1981-1992 ◽  
Author(s):  
Young K. Cho ◽  
Cheng-Shu Li ◽  
David V. Smith
Keyword(s):  
Electrical Stimulation ◽  
Brain Stem ◽  
Taste Preference ◽  
Gastric Distension ◽  
Physiological Factors ◽  
Homocysteic Acid ◽  
Ipsilateral Stimulation ◽  
Gustatory Information ◽  
The Brain ◽  
Stimulation Of

Gustatory responses in the brain stem are modifiable by several physiological factors, including blood insulin and glucose, intraduodenal lipids, gastric distension, and learning, although the neural substrates for these modulatory effects are not known. Stimulation of the lateral hypothalamus (LH) produces increases in food intake and alterations in taste preference behavior, whereas damage to this area has opposite effects. In the present study, we investigated the effects of LH stimulation on the neural activity of taste-responsive cells in the nucleus of the solitary tract (NST) of the hamster. Bipolar stimulating electrodes were bilaterally implanted in the LH, and the responses of 99 neurons in the NST, which were first characterized for their taste sensitivities, were tested for their response to both ipsilateral and contralateral LH stimulation. Half of the taste-responsive cells in the NST (49/99) were modulated by LH stimulation. Contralateral stimulation was more often effective (41 cells) than ipsilateral (13 cells) and always excitatory; 10 cells were excited bilaterally. Six cells were inhibited by ipsilateral stimulation. A subset of these cells ( n = 13) was examined for the effects of microinjection of dl-homocysteic acid (DLH), a glutamate receptor agonist, into the LH. The effects of electrical stimulation were completely mimicked by DLH, indicating that cell somata in and around the LH are responsible for these effects. Other cells ( n = 14) were tested for the effects of electrical stimulation of the LH on the responses to stimulation of the tongue with 0.032 M sucrose, NaCl, and quinine hydrochloride, and 0.0032 M citric acid. Responses to taste stimuli were more than doubled by the excitatory influence of the LH. These data show that the LH, in addition to its role in feeding and metabolism, exerts descending control over the processing of gustatory information through the brain stem.

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.

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