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The role of substance P in the glutamatergic transmission in the reticular formation near the nucleus ambiguus in rats
Author(s) -
Himi Naoyuki,
Koga Tomoshige,
Tsujioka Katsuhiko
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a365-a
Subject(s) - nucleus ambiguus , glutamatergic , nucleus , reticular connective tissue , substance p , neuroscience , reticular formation , chemistry , seiche , transmission (telecommunications) , biology , anatomy , glutamate receptor , medulla oblongata , central nervous system , telecommunications , computer science , geology , neuropeptide , biochemistry , receptor , seismology
In order to estimate the neuronal mechanism of switching autonomic reactions in medulla oblongata, we examined the response of neurons in the reticular formation near the nucleus ambiguus (NA) to the administration of substance P (SP). Whole‐cell recording was applied to the neurons near the NA in coronal slice preparations of medulla oblongata isolated from infant rat. In the 8 of 18 neurons, bath application of SP (1μM) increased the frequency of spontaneous activities. In contrast, 4 neurons showed inhibited response by application of SP, and other 6 neurons showed no response. Several neurons were clamped at −60mV and recorded EPSCs evoked by electrical stimulation of adjacent area to the recording neuron. Bath application of SP induced excitatory effects on the both amplitude of evoked inward EPSCs and frequency of spontaneous activities. These effects of SP were abolished by application of non‐NMDA type glutamate receptor antagonists, CNQX. Our previous studies have shown that administration of neurokinin‐1 receptor (one of the a representative receptor of SP) antagonist near the NA inhibited gastric and respiratory movement in anesthetized rat. These results suggested that SP acts as neuromediator in the glutamatergic transmission near NA and participated in generating certain autonomic reactions.