Excitatory responses evoked in prefrontal cortex by mediodorsal thalamic nucleus stimulation: influence of anaesthesia

Pirot, Sylvain; Głowiński, J.; Thierry, Anne‐Marie

doi:10.1016/0014-2999(95)00377-w

Cited by 30 publications

(25 citation statements)

References 30 publications

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“…Pirot et al [5], [61] showed that MD stimulation evoked two categories of unitary responses in the mPFC, which were distinguished by their latencies: short (3.46±0.05 ms) and long (13.67±0.22 ms). Short-latency responses correspond to the actual recruitment of MD-mPFC thalamocortical fibers, whereas long-latency responses correspond to the activation of intracortical axon collaterals, originating from mPFC-MD corticothalamic fibers.…”

Section: Resultsmentioning

confidence: 99%

Muscarinic and Nicotinic Modulation of Thalamo-Prefrontal Cortex Synaptic Pasticity In Vivo

et al. 2012

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The mediodorsal nucleus of the thalamus (MD) is a rich source of afferents to the medial prefrontal cortex (mPFC). Dysfunctions in the thalamo-prefrontal connections can impair networks implicated in working memory, some of which are affected in Alzheimer disease and schizophrenia. Considering the importance of the cholinergic system to cortical functioning, our study aimed to investigate the effects of global cholinergic activation of the brain on MD-mPFC synaptic plasticity by measuring the dynamics of long-term potentiation (LTP) and depression (LTD) in vivo. Therefore, rats received intraventricular injections either of the muscarinic agonist pilocarpine (PILO; 40 nmol/µL), the nicotinic agonist nicotine (NIC; 320 nmol/µL), or vehicle. The injections were administered prior to either thalamic high-frequency (HFS) or low-frequency stimulation (LFS). Test pulses were applied to MD for 30 min during baseline and 240 min after HFS or LFS, while field postsynaptic potentials were recorded in the mPFC. The transient oscillatory effects of PILO and NIC were monitored through recording of thalamic and cortical local field potentials. Our results show that HFS did not affect mPFC responses in vehicle-injected rats, but induced a delayed-onset LTP with distinct effects when applied following PILO or NIC. Conversely, LFS induced a stable LTD in control subjects, but was unable to induce LTD when applied after PILO or NIC. Taken together, our findings show distinct modulatory effects of each cholinergic brain activation on MD-mPFC plasticity following HFS and LFS. The LTP-inducing action and long-lasting suppression of cortical LTD induced by PILO and NIC might implicate differential modulation of thalamo-prefrontal functions under low and high input drive.

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Section: Resultsmentioning

confidence: 99%

Muscarinic and Nicotinic Modulation of Thalamo-Prefrontal Cortex Synaptic Pasticity In Vivo

et al. 2012

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“…15 It has been reported that the excitability of the PFC and the excitatory output from the PFC are predominantly dependent on NMDA receptor function. 16 In this study, thiopental sodium decreased NMDA-gated currents in the PFC pyramidal neurons, which may decrease the excitability of the PFC.…”

Section: Discussionmentioning

confidence: 99%

Effect of thiopental sodium on N-methyl-D-aspartate-gated currents

Liu

Ti-jun

Yao

2006

Can J Anesth/J Can Anesth

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Purpose: N-methyl-D-aspartate (NMDA) receptors in the prefrontal cortex (PFC) are closely related with the excitability of pyramidal neurons and PFC function. As the effect of thiopental sodium on the central nervous system may partly result from the inhibition of PFC NMDA receptors, we investigated the effect of thiopental sodium with different concentrations on NMDA-gated currents in acutely dissociated rat PFC pyramidal neurons. We sought to determine whether thiopental sodium inhibits NMDA receptor function.Methods: Three to four week old male Sprague-Dawley rats were sacrificed and the PFC was dissected. Pyramidal neurons from the PFC were prepared and standard whole-cell patch clamp recordings were performed. Escalating concentrations from 3-1000 µM NMDA were applied 100 µm from the pyramidal cells, and the concentration in the effect compartment related to 50% effect (EC50) of NMDA was determined for the ensuing experiments. One hundred µM NMDA alone (control) or NMDA with different concentrations (10-1000 µM) of thiopental sodium were applied. After the inhibitory concentration, in 50% of NMDA effect (IC50) of thiopental sodium was established this IC50 and NMDA 3-1000 µM were applied 100 µm from the pyramidal cells. The EC50 value of NMDA under the effect of IC50 thiopental sodium was determined.Results: N-methyl-D-aspartate induced inward currents in a concentration-dependent manner, which were completely antagonized by 50 µM AP5. The maximal amplitude of NMDAinduced current was 1.15 ± 0.27 nA. The EC50 of NMDA was 53.6 ± 12.4 µM. The NMDA (100 µM)-gated current was inhibited by thiopental sodium in a concentration-dependent manner, and the IC50 of thiopental sodium was 33.6 ± 6.1 µM. Under the effect of 33.6 µM thiopental sodium, the maximal amplitude of NMDA-induced current was 0.87 ± 0.17 nA. The concentration-response curve of NMDA was shifted rightwards. The EC50 of NMDA was 128 ± 15 µM, which was greater than that of NMDA without thiopental sodium (P < 0.01). Conclusions:Thiopental sodium decreases NMDA-gated currents in acutely dissociated rat prefrontal cortical pyramidal neurons in a concentration-dependent manner. Objectif : Les récepteurs de N-méthyl-D-aspartate (NMDA) dans le cortex préfrontal (CPF) sont en lien étroit avec l'excitabilité des neurones pyramidaux et la fonction du CPF. L'effet du thio-

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“…In mammals, pyramidal neurons are the main excitatory cells in the prefrontal cortex (PFC), which is representative of 70% of all neurons [12]. The excitability of the PFC and the excitatory output from the PFC is basically dependent upon the function of NMDA receptors [13].…”

Section: Introductionmentioning

confidence: 99%

Pretreatment with Dexmedetomidine or Thiopental Decreases Myoclonus after Etomidate: A Randomized, Double-Blind Controlled Trial

Mızrak¹,

Koruk²,

Bilgi³

et al. 2010

Journal of Surgical Research

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Excitatory responses evoked in prefrontal cortex by mediodorsal thalamic nucleus stimulation: influence of anaesthesia

Cited by 30 publications

References 30 publications

Muscarinic and Nicotinic Modulation of Thalamo-Prefrontal Cortex Synaptic Pasticity In Vivo

Muscarinic and Nicotinic Modulation of Thalamo-Prefrontal Cortex Synaptic Pasticity In Vivo

Effect of thiopental sodium on N-methyl-D-aspartate-gated currents

Pretreatment with Dexmedetomidine or Thiopental Decreases Myoclonus after Etomidate: A Randomized, Double-Blind Controlled Trial

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