Abstract
Zinc is found throughout the CNS in synaptic vesicles of glutamatergic neurons and has been suggested to have a modulatory role in the brain because of its interaction with voltage- and ligand-gated ion channels. We took advantage of zinc transporter 3 knockout mice, which lack vesicular zinc, to study the possible physiological role of this heavy metal in hippocampal mossy fiber neurotransmission. We examined postsynaptic responses evoked by mossy fiber activation, recorded in CA3 pyramidal cells in hippocampal slices prepared from zinc transporter 3 knockout and wild-type mice. Field-potential response threshold and amplitude, input-output curves, and paired-pulse evoked responses were the same in slices from zinc transporter 3 knockout and wild-type mice. Furthermore, neither amplitude nor duration of pharmacologically isolated N-methyl-D-aspartate, non-N-methyl-D-aspartate, GABAA, and GABAB receptor-mediated postsynaptic potentials differed between zinc transporter 3 knockout and wild-type mice. There was no difference in the magnitude of epileptiform discharges evoked by repetitive stimulation or kainic acid application. However, in slices from zinc transporter 3 knockout mice, there was greater attenuation of GABAA-mediated inhibitory postsynaptic potentials during tetanic stimulation compared with slices from wild-type animals. We conclude that lack of vesicular zinc in mossy fibers does not significantly affect the mossy fiber-associated synaptic excitability of CA3 pyramidal cells; however, zinc may modulate GABAergic synaptic transmission under conditions of intensive activation.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 237-248 |
| Number of pages | 12 |
| Journal | Neuroscience |
| Volume | 116 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 15 2003 |
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Keywords
- GABAergic inhibition
- Glutamatergic excitation
- Hippocampus
ASJC Scopus subject areas
- Neuroscience(all)
Cite this
Lack of vesicular zinc in mossy fibers does not affect synaptic excitability of CA3 pyramidal cells in zinc transporter 3 knockout mice. / Lopantsev, V.; Wenzel, H. J.; Cole, T. B.; Palmiter, R. D.; Schwartzkroin, Philip A.
In: Neuroscience, Vol. 116, No. 1, 15.01.2003, p. 237-248.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Lack of vesicular zinc in mossy fibers does not affect synaptic excitability of CA3 pyramidal cells in zinc transporter 3 knockout mice
AU - Lopantsev, V.
AU - Wenzel, H. J.
AU - Cole, T. B.
AU - Palmiter, R. D.
AU - Schwartzkroin, Philip A
PY - 2003/1/15
Y1 - 2003/1/15
N2 - Zinc is found throughout the CNS in synaptic vesicles of glutamatergic neurons and has been suggested to have a modulatory role in the brain because of its interaction with voltage- and ligand-gated ion channels. We took advantage of zinc transporter 3 knockout mice, which lack vesicular zinc, to study the possible physiological role of this heavy metal in hippocampal mossy fiber neurotransmission. We examined postsynaptic responses evoked by mossy fiber activation, recorded in CA3 pyramidal cells in hippocampal slices prepared from zinc transporter 3 knockout and wild-type mice. Field-potential response threshold and amplitude, input-output curves, and paired-pulse evoked responses were the same in slices from zinc transporter 3 knockout and wild-type mice. Furthermore, neither amplitude nor duration of pharmacologically isolated N-methyl-D-aspartate, non-N-methyl-D-aspartate, GABAA, and GABAB receptor-mediated postsynaptic potentials differed between zinc transporter 3 knockout and wild-type mice. There was no difference in the magnitude of epileptiform discharges evoked by repetitive stimulation or kainic acid application. However, in slices from zinc transporter 3 knockout mice, there was greater attenuation of GABAA-mediated inhibitory postsynaptic potentials during tetanic stimulation compared with slices from wild-type animals. We conclude that lack of vesicular zinc in mossy fibers does not significantly affect the mossy fiber-associated synaptic excitability of CA3 pyramidal cells; however, zinc may modulate GABAergic synaptic transmission under conditions of intensive activation.
AB - Zinc is found throughout the CNS in synaptic vesicles of glutamatergic neurons and has been suggested to have a modulatory role in the brain because of its interaction with voltage- and ligand-gated ion channels. We took advantage of zinc transporter 3 knockout mice, which lack vesicular zinc, to study the possible physiological role of this heavy metal in hippocampal mossy fiber neurotransmission. We examined postsynaptic responses evoked by mossy fiber activation, recorded in CA3 pyramidal cells in hippocampal slices prepared from zinc transporter 3 knockout and wild-type mice. Field-potential response threshold and amplitude, input-output curves, and paired-pulse evoked responses were the same in slices from zinc transporter 3 knockout and wild-type mice. Furthermore, neither amplitude nor duration of pharmacologically isolated N-methyl-D-aspartate, non-N-methyl-D-aspartate, GABAA, and GABAB receptor-mediated postsynaptic potentials differed between zinc transporter 3 knockout and wild-type mice. There was no difference in the magnitude of epileptiform discharges evoked by repetitive stimulation or kainic acid application. However, in slices from zinc transporter 3 knockout mice, there was greater attenuation of GABAA-mediated inhibitory postsynaptic potentials during tetanic stimulation compared with slices from wild-type animals. We conclude that lack of vesicular zinc in mossy fibers does not significantly affect the mossy fiber-associated synaptic excitability of CA3 pyramidal cells; however, zinc may modulate GABAergic synaptic transmission under conditions of intensive activation.
KW - GABAergic inhibition
KW - Glutamatergic excitation
KW - Hippocampus
UR - http://www.scopus.com/inward/record.url?scp=0037439069&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037439069&partnerID=8YFLogxK
U2 - 10.1016/S0306-4522(02)00570-5
DO - 10.1016/S0306-4522(02)00570-5
M3 - Article
VL - 116
SP - 237
EP - 248
JO - Neuroscience
JF - Neuroscience
SN - 0306-4522
IS - 1
ER -