Gauchy C, Kemel ML, Glowinski J, Besson MJ. In vivo release of endogenously synthesized [3H]GABA from the cat substantia nigra and the pallido-entopeduncular nuclei.
Brain Res 1980;
193:129-41. [PMID:
7378813 DOI:
10.1016/0006-8993(80)90950-6]
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Abstract
Halothane anesthetized cats were implanted with push--pull cannulae to study the release of [3H]GABA continuously formed from [3H]glutamine in the substantia nigra (SN) and in the pallido-entopeduncular nuclei (PEP). A spontaneous release of [3H]GABA was observed from both structures and it reached a steady state level 1 h after the beginning of the superfusion with [3H]glutamine. In cats implanted with two push--pull cannulae, the local application of potassium (47 mM) in the PEP stimulated the release of [3H]GABA from the ipsilateral SN. In cats implanted with 4 push--pull cannulae, the unilateral 10 min electrical stimulation of the caudate nucleus evoked the release of [3H]GABA not only from the ipsilateral SN, but also in most cases from the contralateral structure. This stimulus also enhanced the release of [3H]GABA from PEP but the effects were mainly observed in the medio-caudal part of the ipsilateral PEP and in the latero-rostral part of the contralateral structure. In all cases, the changes in [3H]GABA release were observed during and after the electrical stimulation. The ipsilateral effects can be attributed to the direct activation of the caudato-PEP or caudato-SN GABAergic neurons. A polysynaptic neuronal loop must be involved in the symmetric contralateral effects.
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