Cobalt blocks postsynaptic responses induced by neurotransmitters in the hippocampus in vitro.
Divalent metals such as cobalt are frequently used by neurophysiologists to prevent synaptic transmission, because they are thought to selectively block presynaptic calcium conductance. Recording intracellularly from hippocampal CA3 pyramidal cells we show that Co2+ (2 mM) is not specific in this action but also diminishes postsynaptic responses mediated by agonists acting at ionotropic and metabotropic glutamatergic receptors, as well as GABAA, GABAB, adenosine, and cholinergic receptors. These findings indicate that a more selective substance should be employed for experiments where neurotransmitter release must be blocked.
Gerber
U
U
Brain Research Institute, University of Zürich, Switzerland.
Gähwiler
B H
BH
D000818:Animals; D016477:Artifacts; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology; D003035:Cobalt / Q000494:pharmacology*; D006624:Hippocampus / Q000187:drug effects* / Q000502:physiology; D015640:Ion Channel Gating / Q000187:drug effects; D018377:Neurotransmitter Agents / Q000037:antagonists & inhibitors*; D051381:Rats; D011919:Rats, Inbred Strains; D011963:Receptors, GABA-A / Q000187:drug effects; D017470:Receptors, Glutamate; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects; D017981:Receptors, Neurotransmitter / Q000145:classification / Q000187:drug effects*; D011983:Receptors, Purinergic / Q000187:drug effects; D013569:Synapses / Q000187:drug effects / Q000502:physiology; D009435:Synaptic Transmission / Q000187:drug effects*
D015220:Calcium Channels; D018377:Neurotransmitter Agents; D011963:Receptors, GABA-A; D017470:Receptors, Glutamate; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter; D011983:Receptors, Purinergic; D003035:Cobalt