Journal of Neurophysiology, Vol 63, Issue 4 707-724, Copyright © 1990 by APS

ARTICLES

Responses from parabrachial gustatory neurons in behaving rats

H. Nishijo and R. Norgren
Department of Behavioral Science, College of Medicine, Pennsylvania State University, Hershey 17033.

1. The responses of a total of 70 single neurons were recorded from the parabrachial nuclei (PBN) in awake rats. In 59 neurons, sapid stimuli (0.5 ml) elicited significant taste responses. Of these 59 neurons, 10 also had significant responses to water. The mean spontaneous rate of the taste neurons was 13.4 +/- 6.9 (SD) spikes/s. Of the remaining 11 neurons, 9 responded significantly only to water; 2 had no significant responses to the standard fluid stimuli. 2. Based on the magnitude of their response to our four standard stimuli, the taste neurons were classified as follows: 42 NaCl-best, 14 sucrose-best, 2 citric acid-best, and 1 QHCl-best. Of these, 25 responded only to one of four sapid stimuli; 20 of these specific cells responded only to NaCl. All the remaining 34 neurons responded to two or more of the four sapid stimuli, with NaCl and sucrose responsiveness dominant. For the 59 taste neurons, the mean entropy for the absolute value of the responses was 0.68; for the excitatory activity alone, it was 0.58. 3. The mean responses to NaCl and sucrose concentration series increased monotonically. Except at the lowest concentration, responses to citric acid also increased monotonically, but with a lower slope. Mean responses to QHCl, however, remained stable or even decreased with increasing concentration. Thus the power functions for the NaCl and sucrose intensity-response series were higher than those of citric acid and QHCl. 4. A hierarchical cluster analysis of 59 parabrachial neurons suggested four different categories: NaCl-best, sucrose-best, citric acid-best, and QHCl-best. These categories were less evident in the two-dimensional space produced by multidimensional analysis, because the positions of NaCl- and sucrose-best neurons formed a continuum in which neural response profiles change successively from sucrose-specific to NaCl-specific. 5. The results were consistent with previous anatomic and neurophysiological data suggesting convergence in the medulla of sensory input from receptors in the nasoincisor ducts (NID) and on the anterior tongue (AT). Taste buds in the NID respond preferentially to sucrose, whereas those on the AT respond more to NaCl.(ABSTRACT TRUNCATED AT 400 WORDS)

This article has been cited by other articles:

				J.-Y. Chen and P. M. Di Lorenzo Responses to Binary Taste Mixtures in the Nucleus of the Solitary Tract: Neural Coding With Firing Rate J Neurophysiol, May 1, 2008; 99(5): 2144 - 2157. [Abstract] [Full Text] [PDF]

				A. C. Spector and S. P. Travers The representation of taste quality in the Mammalian nervous system. Behav Cogn Neurosci Rev, September 1, 2005; 4(3): 143 - 191. [Abstract] [PDF]

				H. Nishijo, T. Uwano, and T. Ono Representation of Taste Stimuli in the Brain Chem Senses, January 1, 2005; 30(suppl_1): i174 - i175. [Full Text] [PDF]

				R. Tamura and R. Norgren Intracranial renin alters gustatory neural responses in the nucleus of the solitary tract of rats Am J Physiol Regulatory Integrative Comp Physiol, April 1, 2003; 284(4): R1108 - R1118. [Abstract] [Full Text] [PDF]

				R. F. Lundy Jr. and R. Norgren Pontine Gustatory Activity Is Altered by Electrical Stimulation in the Central Nucleus of the Amygdala J Neurophysiol, February 1, 2001; 85(2): 770 - 783. [Abstract] [Full Text] [PDF]

				R. Tamura, T. Kondoh, T. Ono, H. Nishijo, and K. Torii Effects of Repeated Cold Stress on Activity of Hypothalamic Neurons in Rats During Performance of Operant Licking Task J Neurophysiol, December 1, 2000; 84(6): 2844 - 2858. [Abstract] [Full Text] [PDF]

				H. Nishijo, T. Ono, T. Uwano, T. Kondoh, and K. Torii Hypothalamic and Amygdalar Neuronal Responses to Various Tastant Solutions during Ingestive Behavior in Rats J. Nutr., April 1, 2000; 130(4): 954 - 954. [Abstract] [Full Text]

				A. Hajnal, K. Takenouchi, and R. Norgren Effect of Intraduodenal Lipid on Parabrachial Gustatory Coding in Awake Rats J. Neurosci., August 15, 1999; 19(16): 7182 - 7190. [Abstract] [Full Text] [PDF]

				H. Nishijo, T. Uwano, R. Tamura, and T. Ono Gustatory and Multimodal Neuronal Responses in the Amygdala During Licking and Discrimination of Sensory Stimuli in Awake Rats J Neurophysiol, January 1, 1998; 79(1): 21 - 36. [Abstract] [Full Text] [PDF]

				H. Nishijo and R. Norgren Parabrachial Neural Coding of Taste Stimuli in Awake Rats J Neurophysiol, November 1, 1997; 78(5): 2254 - 2268. [Abstract] [Full Text] [PDF]

				R. Tamura and R. Norgren Repeated sodium depletion affects gustatory neural responses in the nucleus of the solitary tract of rats Am J Physiol Regulatory Integrative Comp Physiol, October 1, 1997; 273(4): R1381 - R1391. [Abstract] [Full Text] [PDF]

				C. B. Halsell and S. P. Travers Anterior and Posterior Oral Cavity Responsive Neurons Are Differentially Distributed Among Parabrachial Subnuclei in Rat J Neurophysiol, August 1, 1997; 78(2): 920 - 938. [Abstract] [Full Text] [PDF]

				T. Oyoshi, H. Nishijo, T. Asakura, Y. Takamura, and T. Ono Emotional and Behavioral Correlates of Mediodorsal Thalamic Neurons during Associative Learning in Rats J. Neurosci., September 15, 1996; 16(18): 5812 - 5829. [Abstract] [Full Text] [PDF]