Application of L-glutamic acid and substance P to the substantia nigra modulates in vivo [3H]serotonin release in the basal ganglia of the cat.
L-Glutamic acid or substance P were applied to the caudate nucleus (CN) or substantia nigra (SN) and their effects on local, spontaneous, in vivo [3H]serotonin ([3H]5-HT) release as well as [3H]5-HT release in the contralateral CN and SN were studied using cats implanted with push-pull cannulae. L-Glutamic acid (5 x 10(-5) M), when applied to the CN or SN inhibited the local release of [3H]5-HT but did not affect release in the contralateral CN and SN. In the SN, the L-glutamic acid effect was blocked by L-glutamic acid diethylester. Substance P (10(-7) M) applied to the SN induced an increase in [3H]5-HT release that was delayed in onset. Furthermore, [3H]5-HT release was elevated in the contralateral CN immediately upon the application of substance P to the SN. These results suggest that L-glutamic acid and substance P may control 5-HT transmission in the basal ganglia.
D000818:Animals; D002415:Cats; D002421:Caudate Nucleus / Q000378:metabolism*; D003864:Depression, Chemical; D018691:Excitatory Amino Acid Antagonists; D005260:Female; D005971:Glutamates / Q000494:pharmacology* / Q000502:physiology; D018698:Glutamic Acid; D008297:Male; D012701:Serotonin / Q000378:metabolism*; D013373:Substance P / Q000494:pharmacology* / Q000502:physiology; D013378:Substantia Nigra / Q000378:metabolism*
D018691:Excitatory Amino Acid Antagonists; D005971:Glutamates; C011829:glutamic acid diethyl ester; D012701:Serotonin; D013373:Substance P; D018698:Glutamic Acid