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T Galli

Publications and source records attributed to T Galli.

At least 37 records · Page 2Linked to original sources
PubMed1998

A novel tetanus neurotoxin-insensitive vesicle-associated membrane protein in SNARE complexes of the apical plasma membrane of epithelial cells.

The importance of soluble N-ethyl maleimide (NEM)-sensitive fusion protein (NSF) attachment protein (SNAP) receptors (SNAREs) in synaptic vesicle exocytosis is well established because it has been demonstrated that clostridial neurotoxins (NTs) proteolyze the vesicle SNAREs (v-SNAREs) vesicle-associated membrane protein (VAMP)/brevins and their partners, the target SNAREs (t-SNAREs) syntaxin 1 and SNAP25. Yet, several exocytotic events, including apical exocytosis in epithelial cells, are insensitive to numerous clostridial NTs, suggesting the presence of SNARE-independent mechanisms of exocytosis. In this study we found that syntaxin 3, SNAP23, and a newly identified VAMP/brevin, tetanus neurotoxin (TeNT)-insensitive VAMP (TI-VAMP), are insensitive to clostridial NTs. In epithelial cells, TI-VAMP-containing vesicles were concentrated in the apical domain, and the protein was detected at the apical plasma membrane by immunogold labeling on ultrathin cryosections. Syntaxin 3 and SNAP23 were codistributed at the apical plasma membrane where they formed NEM-dependent SNARE complexes with TI-VAMP and cellubrevin. We suggest that TI-VAMP, SNAP23, and syntaxin 3 can participate in exocytotic processes at the apical plasma membrane of epithelial cells and, more generally, domain-specific exocytosis in clostridial NT-resistant pathways.

Amino Acid Sequence↗
PubMed1998

Interaction of Munc-18-2 with syntaxin 3 controls the association of apical SNAREs in epithelial cells.

The docking/fusion of transport vesicles mediated by the soluble NSF attachment protein receptors (SNAREs) is thought to be regulated by Sec1-related proteins. Munc-18-2, a member of this family, is predominantly expressed in the epithelial cells of several tissues. We demonstrate here that Munc-18-2 colocalizes with syntaxin 3 at the apical plasma membrane of intestinal epithelium and Caco-2 cells. The presence of a physical complex of the two proteins is verified by 2-way coimmunoprecipitation. The quantity of the complex is reduced by treatment of Caco-2 cells with the alkylating agent N-ethylmaleimide which also has an inhibitory effect on the ability of Munc-18-2 to associate with syntaxin 3 in vitro. The amount of Munc-18-2 in the complex increases upon treatment of the cells with the protein kinase C activator phorbol myristate acetate, indicating a functional connection between the complex and cell signalling. Increasing the amount of Munc-18-2 bound to syntaxin 3 by overexpression results in a marked decrease in the SNARE proteins SNAP-23 and cellubrevin bound to the syntaxin. These results define a novel functional complex of Munc-18-2 and syntaxin 3 involved in the regulation of apical membrane transport.

Animals↗
PubMed1998

[Breast carcinoma in men. The surgical treatment of a case under our observation].

A case of male breast carcinoma in a very young subject (seventeen years old) is described. Breast carcinoma in male is infrequent, and at a so young age it is really rare. The patient was subjected to "Patey" mastectomy with removing the lymph nodes of the breast with the tumor, and subcutaneous mastectomy at the opposite side breast. As agreed with the oncologist other therapy was carried out.

Adolescent↗
PubMed1996

Rab4 and cellubrevin define different early endosome populations on the pathway of transferrin receptor recycling.

During receptor mediated endocytosis, at least a fraction of recycling cargo typically accumulates in a pericentriolar cluster of tubules and vesicles. However, it is not clear if these endosomal structures are biochemically distinct from the early endosomes from which they are derived. To better characterize this pericentriolar endosome population, we determined the distribution of two endogenous proteins known to be functionally involved in receptor recycling [Rab4, cellubrevin (Cbvn)] relative to the distribution of a recycling ligand [transferrin (Tfn)] as it traversed the endocytic pathway. Shortly after internalization, Tfn entered a population of early endosomes that contained both Rab4 and Cbvn, demonstrated by triple label immunofluorescence confocal microscopy. Tfn then accumulated in the pericentriolar cluster of recycling vesicles (RVs). However, although these pericentriolar endosomes contained Cbvn, they were strikingly depleted of Rab4. The ability of internalized Tfn to reach the Rab4-negative population was not blocked by nocodazole, although the characteristic pericentriolar location of the population was not maintained in the absence of microtubules. Similarly, Rab4-positive and -negative populations remained distinct in cells treated with brefeldin A, with only Rab4-positive elements exhibiting the extended tubular morphology induced by the drug. Thus, at least with respect to Rab4 distribution, the pathway of Tfn receptor recycling consists of at least two biochemically and functionally distinct populations of endosomes, a Rab4-positive population of early endosomes to which incoming Tfn is initially delivered and a Rab4-negative population of recycling vesicles that transiently accumulates Tfn on its route back to the plasma membrane.

Animals↗
PubMed1996

The V0 sector of the V-ATPase, synaptobrevin, and synaptophysin are associated on synaptic vesicles in a Triton X-100-resistant, freeze-thawing sensitive, complex.

Anti-synaptobrevin 2 immunoprecipitates obtained from freshly prepared Triton X-100 extracts of rat synaptosomes contained, in addition to synaptophysin, a 10-kDa band, which we identified by peptide sequencing and Western blotting as the c subunit of the vacuolar proton pump (V-ATPase) also called ductin or mediatophore. Ac39 and Ac116, two other transmembrane subunits of the V0 sector of the V-ATPase, were also found by Western blotting to be enriched in the immunoprecipitates. None of these V-ATPase subunits, or synaptophysin, was present in anti-synaptobrevin 2 immunoprecipitates obtained from frozen-thawed Triton X-100 extracts, which were greatly enriched, instead, in SNAP-25 and syntaxin 1. Accordingly, V-ATPase subunit c was found in anti-synaptophysin immunoprecipitates. Thus, the two complexes appear to be mutually exclusive. Subcellular fractionation of rat brain demonstrated that V-ATPase subunit c is localized with synaptobrevin 2 and synaptophysin in synaptic vesicles. The coprecipitation of V-ATPase subunit c with the synaptobrevin-synaptophysin complex suggests that this interaction may play a role in recruiting the proton pump into synaptic vesicles. Freeze-thawing, which involves a mild denaturing step, may produce a conformational change which dissociates the complex and mimics a change which occurs in vivo as a prerequisite to SNARE complex formation.

Amino Acid Sequence↗
PubMed1995

v- and t-SNAREs in neuronal exocytosis: a need for additional components to define sites of release.

Synaptic vesicle recycling is a specialized form of membrane recycling which takes place in all cells between early endosomes and the plasmalemma. Synaptic vesicles exocytosis is highly regulated and occurs only at presynaptic active zones. In contrast, exocytosis of endosome-derived vesicles of the housekeeping recycling pathway takes place constitutively and throughout the cell surface. Since v- and t-SNAREs play a key role in membrane interactions leading to fusion, unique v- and t-SNAREs may be implicated in synaptic vesicle exocytosis. It was found, however, that the same v-SNAREs of the synaptobrevin family are found both on synaptic vesicles and on endosome-derived vesicles which undergo constitutive fusion. Likewise, t-SNAREs which act as plasmalemmal receptors for synaptic vesicles are not restricted to synaptic active zones. Thus, v- and t-SNAREs interactions may define which organelles can fuse with the plasmalemma, but require additional components to define properties of the exocytotic reaction which are specific for distinct classes of secretory organelles.

Animals↗
PubMed1995

Cellubrevin and synaptobrevins: similar subcellular localization and biochemical properties in PC12 cells.

There is strong evidence to indicate that proteins of the synaptobrevin family play a key role in exocytosis. Synaptobrevin 1 and 2 are expressed at high concentration in brain where they are localized on synaptic vesicles. Cellubrevin, a very similar protein, has a widespread tissue distribution and in fibroblasts is localized on endosome-derived, transferin receptor-positive vesicles. Since brain cellubrevin is not detectable in synaptic vesicles, we investigated whether cellubrevin and the synaptobrevins are differentially targeted when co-expressed in the same cell. We report that in the nervous system cellubrevin is expressed at significant levels only by glia and vascular cells. However, cellubrevin is coexpressed with the two synaptobrevins in PC12 cells, a neuroendocrine cell line which contains synaptic vesicle-like microvesicles. In PC12 cells, cellubrevin has a distribution very similar to that of synaptobrevin 1 and 2. The three proteins are targeted to neurites which exclude the transferrin receptor and are enriched in synaptic-like microvesicles and dense-core granules. They are recovered in the synaptic-like microvesicle peak of glycerol velocity gradients, have a similar distribution in isopycnic fractionation and are coprecipitated by anti-synaptobrevin 2 immunobeads. Finally, cellubrevin, like the synaptobrevins, interact with the neuronal t-SNAREs syntaxin 1 and SNAP-25. These results suggest that cellubrevin and the synaptobrevins have similar function and do not play a specialized role in constitutive and regulated exocytosis, respectively.

Amino Acid Sequence↗
PubMed1995

Health resource utilization in ABMT with and without G-CSF in stage III/IV breast cancer patients.

G-CSF has been available since 1991 for use in patients receiving high-dose chemotherapy/ABMT, and while it has been shown to effectively reduce the risk of febrile neutropenia, its cost effectiveness has been open to question. In this small retrospective study, five indicators of the consumption of health care resources were examined in stage III/IV breast cancer patients who received high-dose chemotherapy with ABMT or peripheral stem cell support. The study covered the time periods before and after the availability of G-CSF. The results showed that patients who received G-CSF had reductions in length of hospital stay of 20% (the purged marrow group) and 17% (nonpurged group), compared with similar groups that did not receive the growth factor; the shortest lengths of stay were seen in the peripheral stem cell group, all of whom received G-CSF. Other findings, including number of days the ANC fell below 500, total days of G-CSF use, and total days of antibiotic use, are presented.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

NMDA and carbachol but not AMPA affect differently the release of [3H]GABA in striosome- and matrix-enriched areas of the rat striatum.

The effects of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA; 10(-3) M), N-methyl-D-aspartate (10(-3) M, in the absence of magnesium or presence of AMPA) and carbachol (10(-3) M) on the release of preloaded [3H]gamma-aminobutyric acid ([3H]GABA) from microdiscs of tissue punched out from sagittal brain slices in striosome- or matrix-enriched areas of the rat striatum have been compared. Although AMPA stimulated similarly the release of [3H]GABA in both striatal compartments, the release of [3H]GABA evoked by either N-methyl-D-aspartate (in the presence of AMPA) or carbachol was more pronounced in matrix- than in striosome-enriched areas. AMPA- and N-methyl-D-aspartate- (in the absence of magnesium) evoked responses were reduced but not abolished in the presence of tetrodotoxin (10(-6) M) in both compartments while the carbachol-evoked release of [3H]GABA was decreased by tetrodotoxin only in the matrix. The interruption of cholinergic transmission by the combined application of atropine (10(-5) M) and pempidine (10(-4) M) was without effect on the AMPA-evoked release of [3H]GABA, but it reduced the N-methyl-D-aspartate- (in the absence of magnesium or presence of AMPA) evoked release of [3H]GABA in both compartments, these reductions being of similar amplitude than those observed with tetrodotoxin.

Animals↗
PubMed1994

Opposite presynaptic regulations by glutamate through NMDA receptors of dopamine synthesis and release in rat striatal synaptosomes.

Purified striatal synaptosomes were superfused continuously with L-[3,5-3H]tyrosine to measure simultaneously the synthesis ([3H]water formed during the conversion of [3H]tyrosine into [3H]DOPA) and the release of [3H]dopamine ([3H]DA). Glutamate (10(-3) M) and NMDA (10(-3) M, in the absence of Mg2+) stimulated the release of [3H]DA, but they reduced the efflux of [3H]water. This reduction of [3H]DA synthesis was blocked by 2-amino-5-phosphonovalerate indicating the involvement of NMDA receptors. Although D,L-alpha-amino-3-hydroxy-5-methyl-4-isoxazole-4-propionate (AMPA) and kainate stimulated the release of [3H]DA, they did not affect its synthesis. The glutamate-evoked inhibition of [3H]DA synthesis was prevented when synaptosomes were superfused continuously with adenosine deaminase plus quinpirole, a treatment which markedly reduces the phosphorylation of tyrosine hydroxylase by cAMP dependent protein kinase. The opposite effects of glutamate on [3H]DA synthesis and release were mimicked by ionomycin (10(-6) M). It is proposed that both an activation of a cyclic nucleotide phosphodiesterase and a dephosphorylation of tyrosine hydroxylase linked to the influx of calcium through NMDA receptors is responsible for the inhibition of dopamine synthesis by glutamate and that calcineurin could play a critical role in these processes.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1994

Tetanus toxin-mediated cleavage of cellubrevin impairs exocytosis of transferrin receptor-containing vesicles in CHO cells.

Cellubrevin is a member of the synaptobrevin/VAMP family of SNAREs, which has a broad tissue distribution. In fibroblastic cells it is concentrated in the vesicles which recycle transferrin receptors but its role in membrane trafficking and fusion remains to be demonstrated. Cellubrevin, like the synaptic vesicle proteins synaptobrevins I and II, can be cleaved by tetanus toxin, a metallo-endoprotease which blocks neurotransmitter release. However, nonneuronal cells are unaffected by the toxin due to lack of cell surface receptors for its heavy chain. To determine whether cellubrevin cleavage impairs exocytosis of recycling vesicles, we tested the effect of tetanus toxin light chain on the release of preinternalized transferrin from streptolysin-O-perforated CHO cells. The release was found to be temperature and ATP dependent as well as NEM sensitive. Addition of tetanus toxin light chain, but not of a proteolytically inactive form of the toxin, resulted in a partial inhibition of transferrin release which correlated with the toxin-mediated cleavage of cellubrevin. The residual release of transferrin occurring after complete cellubrevin degradation was still ATP dependent. Our results indicate that cellubrevin plays an important role in the constitutive exocytosis of vesicles which recycle plasmalemma receptors. The incomplete inhibition of transferrin release produced by the toxin suggests the existence of a cellubrevin-independent exocytotic mechanism, which may involve tetanus toxin-insensitive proteins of the synaptobrevin/VAMP family.

Animals↗
PubMed1992

Modulation of GABA release by alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate and N-methyl-D-aspartate receptors in matrix-enriched areas of the rat striatum.

Using a new in vitro superfusion device, the release of preloaded [3H]GABA was examined in microdiscs of tissues taken from sagittal slices in matrix-enriched areas of the rat striatum. Potassium (9 mM, 15 mM) stimulated the release of [3H]GABA in a concentration- and calcium-dependent manner and the veratridine (1 microM)-evoked release of [3H]GABA was completely abolished in the presence of tetrodotoxin (1 microM). The selective glutamatergic agonist alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (1 mM) enhanced the potassium-evoked release of [3H]GABA as well as the basal outflow of [3H]GABA. This latter effect was found to be calcium-dependent, partially diminished by tetrodotoxin (1 microM), completely blocked by 6,7-dinitro-quinoxaline-2,3-dione (0.1 mM), which is generally used as an antagonist of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate receptors, but not affected by (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate (MK801, 10 microM), a specific antagonist of N-methyl-D-aspartate receptors. Similarly, N-methyl-D-aspartate (1 mM) enhanced both the potassium (9 mM) and the alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (1 mM)-evoked release of [3H]GABA but when used alone, due to the presence of magnesium in the superfusion medium, was ineffective on the basal efflux of [3H]GABA. A stimulatory effect of N-methyl-D-aspartate (1 mM) on the basal outflow of [3H]GABA was observed, however, when magnesium was omitted from the superfusion medium. The stimulatory effect of N-methyl-D-aspartate (1 mM) observed in the presence of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate was not potentiated by glycine (1 microM, in the presence of strychnine 1 microM) and the N-methyl-D-aspartate-evoked response seen in the absence of magnesium was not enhanced by D-serine (1 mM), suggesting that endogenous glycine is already acting on N-methyl-D-aspartate receptors. In fact, in the absence of magnesium, 7-chloro-kynurenate (1 mM) completely abolished the stimulatory effect of N-methyl-D-aspartate on the release of [3H]GABA confirming that under our conditions, the glycine site of the N-methyl-D-aspartate receptor is saturated. N-methyl-D-aspartate-evoked responses were all blocked by MK801 (10 microM). Finally, the N-methyl-D-aspartate-evoked response seen in the absence of magnesium was markedly reduced in the presence of tetrodotoxin (1 microM).(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1992

L-glutamate-evoked release of dopamine from synaptosomes of the rat striatum: involvement of AMPA and N-methyl-D-aspartate receptors.

Previously, using purified synaptosomes from the rat striatum, we have shown that agonists of D,L-alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptors stimulate the release of [3H]dopamine continuously synthesized from [3H]tyrosine. Similar results were obtained with N-methyl-D-aspartate in the absence of magnesium. In the present study, using the same approach, attempts were made to determine whether in the presence of magnesium, the combined stimulation of AMPA receptors allows us to demonstrate the presynaptic facilitation of [3H]dopamine release through N-methyl-D-aspartate receptors. L-Glutamate (10(-3) M) markedly stimulated the release of [3H]dopamine from synaptosomes, this effect being about twice that found with AMPA (10(-3) M) while N-methyl-D-aspartate (10(-3) M) even in the presence of glycine (10(-6) M) was ineffective. In agreement with previous results, a stimulatory effect of N-methyl-D-aspartate and glycine was only observed in the absence of magnesium. This response was blocked by 6,7-dinitro-quinoxaline-2,3-dione (3 x 10(-5) M), confirming that this compound, generally used as an AMPA antagonist, also blocks N-methyl-D-aspartate receptors. The AMPA (10(-3) M)-evoked release of [3H]dopamine was markedly potentiated by the combined application of N-methyl-D-aspartate (10(-3) M) and glycine (10(-6) M) in the presence of strychnine, indicating that the concomitant activation of AMPA receptors removes the voltage-dependent magnesium block of N-methyl-D-aspartate receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

In vitro and in vivo inhibition of N-acetyl-L-aspartyl-L-glutamate catabolism by N-acylated L-glutamate analogs.

The dipeptide N-acetyl-aspartyl-glutamic acid (NAAG) present in brain and spinal cord tissues may act as a neurotransmitter at excitatory synapses in the central nervous system. However, pharmacological and biochemical studies of NAAG are hampered by its rapid inactivation in vivo and in vitro by an enzyme that cleaves NAAG into N-acetyl-aspartate and glutamate. This enzyme has been previously named N-acetylated alpha-linked acidic dipeptidase (NAALADase). Based upon our earlier studies on the specificity of this enzyme, we have now designed new competitive inhibitors of this peptidase. N-Succinyl-glutamic acid, 4, was almost as potent as N-acetyl-beta-aspartyl-glutamic acid (beta-NAAG), 2, in inhibiting the hydrolysis of [Glu-3H]NAAG by rat brain membranes, with an IC50 value in the micromolar range. The analogous affinities of the substrate NAAG and of N-succinyl-glutamic acid suggest that the N-acetyl moiety is not an absolute requirement for entry into the active site of the enzyme. Therefore, the acronym NAALADase seems to be incorrect, and peptidase activity against NAAG will be used throughout this manuscript when referring to the enzyme that cleaves NAAG and whose activity is inhibited by quisqualate and beta-NAAG. Two N-acylated glutamic acid analogs, 5 and 6, were also found to be effective inhibitors of the in vitro degradation of NAAG, with Ki values in the micromolar range. Compounds 5 and 6 possess two free carboxylic functions on the N-acyl moiety, one of which could interact with the S1 subsite of the enzyme; the other could chelate the Zn++ cation involved in the catalytic hydrolysis of NAAG.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylation↗
PubMed1991

Specific role of N-acetyl-aspartyl-glutamate in the in vivo regulation of dopamine release from dendrites and nerve terminals of nigrostriatal dopaminergic neurons in the cat.

Levels of N-acetyl-aspartyl-glutamate measured by high-pressure liquid chromatography were found to be very high in the cat substantia nigra, particularly in the pars compacta, while those in the caudate nucleus were much lower. In halothane-anaesthetized cats implanted with push-pull cannulae, N-acetyl-aspartyl-glutamate (10(-8) M) induced a marked and prolonged release of newly synthesized [3H]dopamine, when infused into the posterior but not into the anterior part of the caudate nucleus. In contrast, in the presence of tetrodotoxin (10(-6) M), N-acetyl-aspartyl-glutamate (10(-8) M) reduced the residual release of [3H]dopamine; this effect was also more pronounced in the posterior than in the anterior part. In the conditions used, as indicated by experiments with [3H]N-acetyl-aspartyl-glutamate no glutamate was formed from the infused N-acetyl-aspartyl-glutamate. Ibotenate (10(-5) M) induced changes in [3H]dopamine release in both the absence and presence of tetrodotoxin, which were closely similar to those observed with N-acetyl-aspartyl-glutamate. Responses induced by either N-acetyl-aspartyl-glutamate or ibotenate were not mediated by N-methyl-D-aspartate receptors since N-methyl-D-aspartate stimulated the release of [3H]dopamine only when used in a high concentration (10(-4) M) and applied in a magnesium-free superfusion medium in both the presence of glycine (10(-6) M) and strychnine (10(-6) M). In addition, the stimulatory effect of N-methyl-D-aspartate persisted in the presence of tetrodotoxin; it was of similar amplitude in both parts of the caudate nucleus and of shorter duration than that evoked by either N-acetyl-aspartyl-glutamate or ibotenate alone. N-Acetyl-aspartyl-glutamate interacted with dopaminergic neurons not only presynaptically in the caudate nucleus but also in the substantia nigra since a marked increase in [3H]dopamine release was observed both from local dendrites and from nerve terminals in the ipsilateral caudate nucleus when N-acetyl-aspartyl-glutamate (10(-7) M) was infused locally into the substantia nigra pars compacta. No effect could be seen in contralateral structures. The isomer of natural N-acetyl-aspartyl-glutamate, beta-N-acetyl-aspartyl-glutamate (10(-7) M), had no effect on [3H]dopamine release when applied similarly in the substantia nigra, thus confirming the specificity of the action of N-acetyl-aspartyl-glutamate.

Animals↗
PubMed1991

Presynaptic facilitation of dopamine release through D,L-alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptors on synaptosomes from the rat striatum.

Purified synaptosomes from the rat striatum were superfused continuously with [3H]tyrosine in order to estimate the release of newly synthesized [3H]dopamine. When tested from 10(-6) to 10(-3) M, several excitatory amino acids or their analogues markedly stimulated the release of [3H]dopamine, their apparent rank order of potency being kainate greater than glutamate = D,L-alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) greater than homocysteate greater than quisqualate greater than aspartate greater than ibotenate. N-acetyl-aspartyl-glutamate was without effect. In addition, in the range of concentrations of 10(-6) to 10(-3) M, the maximal response of glutamate was higher than that of kainate, AMPA or homocysteate, whereas the effects of quisqualate, aspartate and ibotenate, particularly, were of lower amplitude. In favor of the existence of glutamate receptors of the AMPA type on dopaminergic nerve terminals, the stimulatory effect of AMPA (5 x 10(-5) M) on [3H]dopamine release was antagonized by 6,7-dinitroquinoxaline-2,3-dione, 6-cyano-7-nitro-quinoxaline-2,3-dione, tau-D-glutamyl-amino-methyl-sulphonate and tau-D-glutamyl-glycine tested at 10(-4) M. 6,7-Dinitroquinoxaline-2,3-dione was the most potent, whereas L-glutamate diethylester was without effect. As expected D-2-amino-5-phosphonovalerate did not affect the AMPA-evoked response. Further experiments indicated that kainate and quisqualate stimulate the release of [3H]dopamine by acting on quisqualate/kainate or AMPA receptors. The quisqualate-evoked desensitization of AMPA receptors was prevented by concanavalin A (10(-7) M).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗