TY - JOUR
T1 - Hypothalamic histamine release by taste stimuli in freely moving rats
T2 - Possible implication of palatability
AU - Treesukosol, Yada
AU - Ishizuka, Tomoko
AU - Yamamoto, Chizuko
AU - Senda, Kanae
AU - Tsutsumi, Shintaro
AU - Yamatodani, Atsushi
AU - Yamamoto, Takashi
N1 - Funding Information:
Parts of the studies in this article were supported by Grants-in-Aid for 21st Century COE and Scientific Research from the Ministry of Education, Science, Culture and Sports of Japan to T.Y. (17390494 and 16659510).
PY - 2005/10/14
Y1 - 2005/10/14
N2 - Our previous study indicated that taste information via the chorda tympani (CT) activates the central histaminergic system in anesthetized rats. However, the physiological roles of taste-induced histamine release remain unknown, thus to further investigate the relationship between histamine release and gustatory information, in the present study we investigated the effect of taste stimuli infused intraorally on histamine release using in vivo microdialysis in free moving rats. Consistent with findings from our previous study, application of NaCl and HCl caused significant increases in histamine levels further supporting the suggestion that this phenomenon is attributed to the excitation of the CT. When rats were intraorally infused with quinine HCl (QHCl) solution, a significant increase in hypothalamic histamine release was observed. On the other hand, histamine release was decreased by sucrose and saccharin solutions. When rats were conditioned to acquire taste aversion to sucrose solution or saccharin solution, instead of the histamine decrease seen by the palatable solutions, the pattern of histamine release was similar to that seen by QHCl solution. From these observations, it is concluded that the histamine release by the infusion of these tastants may be explained by two mechanisms - by causing a transient increase after taste stimulation and by causing a decrease relative to the tastant's palatability.
AB - Our previous study indicated that taste information via the chorda tympani (CT) activates the central histaminergic system in anesthetized rats. However, the physiological roles of taste-induced histamine release remain unknown, thus to further investigate the relationship between histamine release and gustatory information, in the present study we investigated the effect of taste stimuli infused intraorally on histamine release using in vivo microdialysis in free moving rats. Consistent with findings from our previous study, application of NaCl and HCl caused significant increases in histamine levels further supporting the suggestion that this phenomenon is attributed to the excitation of the CT. When rats were intraorally infused with quinine HCl (QHCl) solution, a significant increase in hypothalamic histamine release was observed. On the other hand, histamine release was decreased by sucrose and saccharin solutions. When rats were conditioned to acquire taste aversion to sucrose solution or saccharin solution, instead of the histamine decrease seen by the palatable solutions, the pattern of histamine release was similar to that seen by QHCl solution. From these observations, it is concluded that the histamine release by the infusion of these tastants may be explained by two mechanisms - by causing a transient increase after taste stimulation and by causing a decrease relative to the tastant's palatability.
KW - Anterior hypothalamus
KW - Histamine
KW - Microdialysis
KW - Palatability
KW - Taste
KW - Taste aversion
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U2 - 10.1016/j.bbr.2005.06.004
DO - 10.1016/j.bbr.2005.06.004
M3 - Article
C2 - 16029900
AN - SCOPUS:24344478805
SN - 0166-4328
VL - 164
SP - 67
EP - 72
JO - Behavioural Brain Research
JF - Behavioural Brain Research
IS - 1
ER -