Elsevier

Behavioural Brain Research

Volume 25, Issue 3, September 1987, Pages 233-246
Behavioural Brain Research

Research paper
The effects of glossopharyngeal and chorda tympani nerve cuts on the ingestion and rejection of sapid stimuli: An electromyographic analysis in the rat

https://doi.org/10.1016/0166-4328(87)90071-4Get rights and content

Abstract

The present study tested the effects of bilateral section of either the chorda tympani or glossopharyngeal nerves on the production of oro-pharyngeal electromyographic (EMG) responses to intra-oral sapid stimulation. The responses of adult rats fitted with intra-oral cannulas and fine-wire electrodes in the anterior digastric (jaw opening) and thyropharyngeus (swallowing) muscles were examined following direct oral stimulation with water and 5 concentrations of sucrose, NaCl, and quinine monohydrochloride (QHCl). One group of rats was tested both before and after bilateral removal of the chorda tympani. A second group of rats was tested subsequent to bilateral removal of the glossopharyngeal nerves. A normal EMG response pattern to suprathreshold QHCl consisted of several intra-oral licks followed by a series of large amplitude mouth openings (gapes). In addition, there was a longer latency to the first swallow following QHCl stimulation compared to water stimulation. Cutting either nerve affected this rejection response to QHCl, but produced little change in the ingestive response to the other stimuli. Following chorda tympani nerve cuts, rats showed an increased latency to the first gape and a small reduction in the number of gapes across the 5 concentrations of QHCl (16%). In contrast, bilateral section of the glossopharyngeal nerves produced a much larger reduction in the number of gapes (54%), but had no effect on the latency to the first gape. In addition, the latency to swallow suprathreshold QHCl was shorter following glossopharyngeal nerve cuts. These observations suggest that gustatory receptors on the anterior tongue, innervated by the chorda tympani, initiate a rejection response, but that receptors on the posterior tongue, innervated by the glossopharyngeal nerve, are necessary for a sustained rejection sequence.

References (59)

  • H.J. Grill et al.

    The taste reactivity test. II. Mimetic responses to gustatory stimuli in chronic thalamic and chronic decerebrate rats

    Brain Res.

    (1978)
  • J.P. Heybach et al.

    Dietary quinine reduces body weight and food intake independent of aversive taste

    Physiol. Behav.

    (1982)
  • M.F. Jacquin et al.

    Trigeminal orosensory deafferentation disrupts feeding and drinking mechanisms in the rat

    Brain Res.

    (1982)
  • Y. Kawamura et al.

    A role of oral afferents in aversion to taste solutions

    Physiol. Behav.

    (1968)
  • T. Murakami et al.

    Reflex responses of single salivatory neurons to stimulation of trigeminal sensory branches in the cat

    Brain Res.

    (1983)
  • C. Pfaffmann et al.

    The sensory and behavioral factors in taste preferences

  • D.V. Smith et al.

    Sensitivity of the rat gustatory system to the rate of stimulus onset

    Physiol. Behav.

    (1975)
  • S.P. Travers et al.

    Convergence of lingual and palatal gustatory neural activity in the nucleus of the solitary tract

    Brain Res.

    (1986)
  • T. Yamamoto et al.

    EMG activities of masticatory muscles during licking in rats

    Physiol. Behav.

    (1982)
  • A.A. Zalewski

    Regeneration of taste buds after transplantation of tongue and ganglia to the anterior chamber of the eye

    Exp. Neurol.

    (1972)
  • N. Akaike et al.

    Taste preference and aversion in rats following denervation of the chorda tympani and the IXth nerve

    Kumamoto Med. J.

    (1965)
  • B. Appelberg

    Species differences in the taste qualities mediated through the glossopharyngeal nerve

    Acta Physiol. Scand.

    (1958)
  • J. Atema

    Structures and functions of the sense of taste in the catfish (Ictalurus natalis)

    Brain Behav. Evol.

    (1971)
  • K.C. Berridge et al.

    Trigeminal-taste interaction in palatability processing

    Science

    (1985)
  • J.C. Chawla et al.

    Glossopharyngeal and vagal neuralgia

    Br. Med. J.

    (1967)
  • G. Ciampini et al.

    Role des afferences glossopharyngiennes et trigeminales dans le declenchment et le deroulement de la deglutition. I. Afferences glossopharyngiennes

    J. Physiol. (Paris)

    (1980)
  • H.A. Franks et al.

    Mechanism of intraoral transport in macaques

    Am. J. Phys. Anthropol.

    (1984)
  • H.J. Grill et al.

    Taste reactivity as a measure of the neural control of palatability

  • H.J. Grill et al.

    Chronically decerebrate rats demonstrate satiation but not bait-shyness

    Science

    (1978)
  • Cited by (80)

    • Regional specialization of the tongue revealed by gustatory ganglion imaging

      2022, iScience
      Citation Excerpt :

      Electrophysiological recordings, anatomical, and behavioral studies have provided strong evidence that the anterior taste pathway is necessary for salt discrimination responses in rodents.14,15,16,17 And evidence supports a greater role of bitter signaling from the posterior taste pathway, especially related to producing aversive oral-facial reflexes such as gapes.18,19,20,21,22,23 Now, with access to advanced functional imaging tools, we have the opportunity to investigate the differences in taste coding across the two taste ganglia both at the population and single-neuron level.

    • Genetic control of oromotor phenotypes: A survey of licking and ingestive behaviors in highly diverse strains of mice

      2017, Physiology and Behavior
      Citation Excerpt :

      ILI intervals > 1 s can therefore be considered interburst intervals. We also examined pauses of intermediate length – pauses < 1 s but > 160 ms represent very brief breaks in licking behavior that may reflect taste reactivity behaviors [41,42] or missed licks (tongue protrusions failing to contact the drinking spout). An ISI of 0 is indicative of a mouse whose burst size and burst number are proportional to the all-strain averages.

    • The bad taste of medicines: Overview of basic research on bitter taste

      2013, Clinical Therapeutics
      Citation Excerpt :

      These are collectively referred to as aversive behaviors. Transection of the glossopharyngeal nerve, which innervates the taste buds of the posterior tongue where T2Rs are densely expressed, virtually eliminates the characteristic aversive oromotor responses to intraorally delivered highly concentrated quinine solutions,98–100 which return when the nerve regenerates.100 Although bitter taste stimuli are often aversive, not all aversive tastes are bitter.

    • Fos positive neurons in the brain stem and amygdala mostly express vesicular glutamate transporter 3 after bitter taste stimulation

      2012, Brain Research
      Citation Excerpt :

      Most mammals consistently reject bitter-tasting substances, such as quinine, they perceive them to be a threat to their survival. Previous studies indicated that quinine could elicit oromotor rejection (Grill et al., 1992; Travers et al., 1987) and c-Fos expression in the NST (King et al., 2000). Lesion-behavioral studies suggested that the lower brainstem mediates the oral rejection response to gustatory stimuli (Grill and Norgren, 1978).

    View all citing articles on Scopus
    View full text