Potential Role of Synaptic Activity to Inhibit LTD Induction in Rat Visual Cortex
Long-term depression (LTD), a widely studied form of activity-dependent synaptic plasticity, is typically induced by prolonged low-frequency stimulation (LFS). Interestingly, LFS is highly effective in eliciting LTD in vitro, but much less so under in vivo conditions; the reasons for the resistance...
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| Language: | English |
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Wiley
2016-01-01
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| Series: | Neural Plasticity |
| Online Access: | http://dx.doi.org/10.1155/2016/1401935 |
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| author | Matthew R. Stewart Hans C. Dringenberg |
| author_facet | Matthew R. Stewart Hans C. Dringenberg |
| author_sort | Matthew R. Stewart |
| collection | DOAJ |
| description | Long-term depression (LTD), a widely studied form of activity-dependent synaptic plasticity, is typically induced by prolonged low-frequency stimulation (LFS). Interestingly, LFS is highly effective in eliciting LTD in vitro, but much less so under in vivo conditions; the reasons for the resistance of the intact brain to express LTD are not well understood. We examined if levels of background electrocorticographic (ECoG) activity influence LTD induction in the thalamocortical visual system of rats under very deep urethane anesthesia, inducing a brain state of reduced spontaneous cortical activity. Under these conditions, LFS applied to the lateral geniculate nucleus resulted in LTD of field postsynaptic potentials (fPSPs) recorded in the primary visual cortex (V1). Pairing LFS with stimulation of the brainstem (pedunculopontine) reticular formation resulted in the appearance of faster, more complex activity in V1 and prevented LTD induction, an effect that did not require muscarinic or nicotinic receptors. Reticular stimulation alone (without LFS) had no effect on cortical fPSPs. These results show that excitation of the brainstem activating system blocks the induction of LTD in V1. Thus, higher levels of neural activity may inhibit depression at cortical synapses, a hypothesis that could explain discrepancies regarding LTD induction in previous in vivo and in vitro work. |
| format | Article |
| id | doaj-art-776ad3eec7bd4883a4d810413e094777 |
| institution | Kabale University |
| issn | 2090-5904 1687-5443 |
| language | English |
| publishDate | 2016-01-01 |
| publisher | Wiley |
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| series | Neural Plasticity |
| spelling | doaj-art-776ad3eec7bd4883a4d810413e0947772025-02-03T01:02:51ZengWileyNeural Plasticity2090-59041687-54432016-01-01201610.1155/2016/14019351401935Potential Role of Synaptic Activity to Inhibit LTD Induction in Rat Visual CortexMatthew R. Stewart0Hans C. Dringenberg1Department of Psychology, Queen’s University, Kingston, ON, K7L 3N6, CanadaDepartment of Psychology, Queen’s University, Kingston, ON, K7L 3N6, CanadaLong-term depression (LTD), a widely studied form of activity-dependent synaptic plasticity, is typically induced by prolonged low-frequency stimulation (LFS). Interestingly, LFS is highly effective in eliciting LTD in vitro, but much less so under in vivo conditions; the reasons for the resistance of the intact brain to express LTD are not well understood. We examined if levels of background electrocorticographic (ECoG) activity influence LTD induction in the thalamocortical visual system of rats under very deep urethane anesthesia, inducing a brain state of reduced spontaneous cortical activity. Under these conditions, LFS applied to the lateral geniculate nucleus resulted in LTD of field postsynaptic potentials (fPSPs) recorded in the primary visual cortex (V1). Pairing LFS with stimulation of the brainstem (pedunculopontine) reticular formation resulted in the appearance of faster, more complex activity in V1 and prevented LTD induction, an effect that did not require muscarinic or nicotinic receptors. Reticular stimulation alone (without LFS) had no effect on cortical fPSPs. These results show that excitation of the brainstem activating system blocks the induction of LTD in V1. Thus, higher levels of neural activity may inhibit depression at cortical synapses, a hypothesis that could explain discrepancies regarding LTD induction in previous in vivo and in vitro work.http://dx.doi.org/10.1155/2016/1401935 |
| spellingShingle | Matthew R. Stewart Hans C. Dringenberg Potential Role of Synaptic Activity to Inhibit LTD Induction in Rat Visual Cortex Neural Plasticity |
| title | Potential Role of Synaptic Activity to Inhibit LTD Induction in Rat Visual Cortex |
| title_full | Potential Role of Synaptic Activity to Inhibit LTD Induction in Rat Visual Cortex |
| title_fullStr | Potential Role of Synaptic Activity to Inhibit LTD Induction in Rat Visual Cortex |
| title_full_unstemmed | Potential Role of Synaptic Activity to Inhibit LTD Induction in Rat Visual Cortex |
| title_short | Potential Role of Synaptic Activity to Inhibit LTD Induction in Rat Visual Cortex |
| title_sort | potential role of synaptic activity to inhibit ltd induction in rat visual cortex |
| url | http://dx.doi.org/10.1155/2016/1401935 |
| work_keys_str_mv | AT matthewrstewart potentialroleofsynapticactivitytoinhibitltdinductioninratvisualcortex AT hanscdringenberg potentialroleofsynapticactivitytoinhibitltdinductioninratvisualcortex |