Blocking of AMPA receptors in the central amygdaloid nucleus modulates the parabrachial nucleus taste responses in rats

( views:50, downloads:0 )
Journal Title:
Volume 56, Issue 06, 2004
Key Word:
parabrachial nucleus;central nucleus of the amygdala;taste;microinjection;6-cyano-7-nitro-quinoxaline-2, 3-dione

Abstract: Taste responses in the parabrachial nucleus (PBN) are significantly affected by stimulation or lesion of the central nucleus of the amygdala (CeA). To examine if the glutamate receptors in the CeA are involved in this modulation, the effects of microinjection of 6-cyano-7-nitro-quinoxaline-2, 3-dione (CNQX), an AMPA receptor antagonist, into the CeA on the activities of PBN taste neurons were observed by using extracellular recording technique. Responses of PBN taste neurons to taste stimuli were observed before and after CNQX administered to the CeA. In general, drug administration produced a time-dependent suppress of the responses in 30% PBN taste neurons, with the firing rates to HCl and QHCl were significantly lowered (P<0.05). According to the best-stimulus category, 40% NaCl-best (6/l5), 30% HCl-best(3/10) and 20% QHCl-best (1/5) neurons decreased their responses to at least one basic taste stimulus after CNQX injection. In HCl- and QHCl-best neruons, the main responses were significantly inhibited after drug injections (P<0.01). The correlation coefficient of responses between the NaCl and the other three tastants decreased after drug administration to the CeA. These results suggest that AMPA receptors within the CeA may be involved in the descending modulation in the PBN taste neurons.

  • [1]Norgren R. Taste pathways to hypothalamus and amygdala. J Comp Neurol 1976; 166:17-30.
  • [2]Norgren R. Gustatory afferents to ventral forebrain. Brain Res1974; 81(2):285-295.
  • [3]Hamilton RB, Norgren R. Central projections of gustatory nerves in the rat. J Comp Neurol 1984; 222(4): 560-577.
  • [4]Whitehead MC. Subdivisions and neuron types of the nucleus of the solitary tract that project to the parabrachial nucleus in the hamster. J Comp Neurol 1990; 301(4): 554-574.
  • [5]Herbert H, Moga MM, Saper CB. Connections of the parabrachial nucleus with the nucleus of the solitary tract and the medullary reticular formation in the rat. J Comp Neurol1990; 293(4): 540-580.
  • [6]Halsell CB. Organization of parabrachial nucleus efferents to the thalamus and amygdala in the golden hamster. J Comp Neurol 1992; 317(1): 57-78.
  • [7]Voshart K, van der Kooy D. The organization of the efferent projections of the parabrachial nucleus to the forebrain in the rat:a retrograde fluorescent double-labeling study. Brain Res 1981;212(2): 271-286.
  • [8]Takeuchi Y, McLean JH, Hopkins DA. Reciprocal connections between the amygdala and parabrachial nuclei: ultrastructural demonstration by degeneration and axonal transport of horseradish peroxidase in the cat. Brain Res 1982; 239(2):583-588.
  • [9]Matsuo R, Shimizu N, Kusano K. Lateral hypothalamic modulation of oral sensory afferent activity in nucleus tractus solitarius neurons of rats. J Neurosci 1984; 4(5): 1201-1207.
  • [10]Di Lorenzo PM. Corticofugal influence on taste responses in the parabrachial pons of the rat. Brain Res 1990; 530(1): 73-84.
  • [11]Di Lorenzo PM, Monroe S. Corticofugal influence on taste responses in the nucleus of the solitary tract in the rat. J Neurophysiol 1995; 74(1): 258-272.
  • [12]Lundy RF Jr, Norgren R. Pontine gustatory activity is altered by electrical stimulation in the central nucleus of the amygdala. J Neurophysiol 2001; 85(2): 770-783.
  • [13]Huang T, Yan J, Kang Y, Role of the central amygdaloid nucleus in shaping the discharge of gustatory neurons in the mt pambrachial nucleus. Brain Res Bull 2003; 61(4): 443-452.
  • [14]Kang Y, Yan JQ, Huang T. Effects of the central amygdaloid nucleus lesions on the gustatory responses in the parabrachial nucleus in rats. Acta Physiol Sin (生理学报) 2003; 55(3): 317-323.
  • [15]Li CS, Smith DV. Glutamate receptor antagonists block gustatory afferent input to the nucleus of the solitary tract. J Neurophysiol1997; 77(3): 1514-1525.
  • [16]Otawa S, Takagi K, Ogawa H. NMDA and non-NMDA receptors mediate taste afferent inputs to cortical taste neurons in rats.Exp Brain Res 1995; 106(3): 391-402.
  • [17]McDonald AJ, Beitz AJ, Larson AA, Kuriyama R, Sellitto C,Madl JE. Co-localization of glutamate and tubulin in putative excitatory neurons of the hippocampus and amygdala: an immunohistochemical study using monoclonal antibodies. Neuroscience1989; 30(2): 405-421.
  • [18]Rogers SW, Hughes TE, Hollmann M, Gasic GP, Deneris ES,Heinemann S. The characterization and localization of the glutamate receptor subunit GluR1 in the rat brain. J Neurosici1991; 11(9): 2713-2724.
  • [19]Yasoshima Y, Morimoto T, Yamamoto T. Different disruptive effects on the acquisition and expression of conditioned taste aversion by blockades of amygdalar ionotropic and metabotropic glutamatergic receptor subtypes in rats. Brain Res 2000; 869 (1-2): 15-24.
  • [20]Li Cs, Cho YK, Smith DV. Taste responses of neurons in the hamster solitary nucleus are modulated by the central nucleus of the amygdala. J Neurophysiol 2002; 88(6): 2979-2992.
  • [21]Smith DV, John SJ, Boughter JD. Neuronal cell types and taste quality coding. Physiol Behavior 2000; 69(1-2): 77-85.
  • [22]Scott TR, Perrotto RS. Intensity coding in pontine taste area:gustatory information is processed similarly throughout rat's brain stem. J Neurophysiol 1980; 44(4): 739-750.
  • [23]Smith DV, Travers JB. A metric for the breadth of tuning of gustatory neurons. Chem Sense Flay 1979; 4: 215-229.
  • [24]Turner BH, Herkenham M. Thalamoamygdaloid projections in the rat: a test of the amygdala's role in sensory processing. J Comp Neurol 1991; 313(2): 295-325.
  • [25]Pomonis JD, Levine AS, Billington CJ. Interaction of the hypothalamic paraventricular nucleus and central nucleus of the amygdala in naloxone blockade of neuropeptide Y-induced feeding revealed by c-fos expression. J Neurosci 1997; 17(13): 5175-5182.
  • [26]Murzi E, Hemandez L, Baptista T. Lateral hypothalamic sites eliciting eating affect medullary taste neurons in rats. Physiol Behav 1986; 36(5): 829-834.
  • [27]Cho YK, Li CS, Smith DV. Descending influences from the lateral hypothalamus and amygdala converge onto medullary taste neurons. Chem Senses 2003; 28(2): 155-171.
WanfangData CO.,Ltd All Rights Reserved
About WanfangData | Contact US
Healthcare Department, Fuxing Road NO.15, Haidian District Beijing, 100038 P.R.China
Tel:+86-010-58882616 Fax:+86-010-58882615