Histamine modulation of glutamate release from hippocampal synaptosomes.
Histamine is widely believed to act as a neuromodulator in the central nervous system. Histaminergic fibers arriving at the hippocampus could be involved in the modulation of glutamatergic neurotransmission. Therefore, we have investigated the effect of histamine on [3H]glutamate release from hippocampal synaptosomes by using a superfusion system. Calcium-dependent [3H]glutamate release was stimulated by KCI or 4-aminopyridine. When submaximal concentrations of the depolarizing agents were used (15 mM KCI or 50 microM 4-aminopyridine), histamine, acting via histamine H1 and H2 receptors, produced a concentration-dependent increase in the evoked release of glutamate. Maximal effect was obtained with 500 microM histamine. Histamine (up to 1 mM) did not modify basal release. These data suggest that histaminergic afferents may modulate activity-dependent glutamatergic presynaptic terminals in the hippocampus.
Rodriguez
F J
FJ
Departamento Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Autónoma de Barcelona, Spain. jrodriguez@cc.uab.es
Lluch
M
M
Dot
J
J
Blanco
I
I
Rodriguez-Alvarez
J
J
D000818:Animals; D018698:Glutamic Acid / Q000378:metabolism*; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D006632:Histamine / Q000494:pharmacology*; D066298:In Vitro Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D011969:Receptors, Histamine H1 / Q000502:physiology; D011970:Receptors, Histamine H2 / Q000502:physiology; D013574:Synaptosomes / Q000187:drug effects* / Q000378:metabolism
D011969:Receptors, Histamine H1; D011970:Receptors, Histamine H2; D018698:Glutamic Acid; D006632:Histamine