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Neurosteroid effects on intracellular calcium and excitotoxicity
Naimová, Žaneta ; Smejkalová, Terézia (advisor) ; Adámek, Pavel (referee)
NMDA receptors belong to the family of ionotropic glutamate receptors, and are involved in synaptic plasticity, learning and memory. However, overactivation by the agonist glutamate can lead to neuronal death - excitotoxicity. Exitotoxicity is a result of excessive calcium influx into the cell through NMDA receptors, and is associated with many cental nervous system (CNS) diseases. Neurosteroids are endogenous compounds capable of NMDA receptor modulation, thus they may have pharmacological potential in the treatment of CNS disorders. The aim of this work was to investigate how pregnanolone sulfate (PA-S) and pregnanolone hemipimelate (PA-hPim) influence somatic calcium and excitotoxicity. We used fluorescence microscopy for recording changes in somatic calcium concentration. We observed that PA-S had no influence on relative somatic calcium concentration. Synthetic analog PA-hPim increased somatic calcium levels slightly. Next, we used oxygen-glucose deprivation (OGD) in vitro to study the influence of neurosteroids on excitotoxicity. Both PA-S and PA-hPim were neuroprotective in the model of acute OGD in vitro. Moreover, PA-S or PA-hPim pretreatment induced ischemic tolerance to a subsequent OGD episode. Our results suggest that neurosteroids PA-S and PA-hPim are potential candidates for the development...
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The role of nociceptive synaptic transmission modulation at the spinal cord level in different pain states
Adámek, Pavel ; Paleček, Jiří (advisor) ; Vaculín, Šimon (referee) ; Vlachová, Viktorie (referee)
Pain is a common symptom of many clinical syndromes and diseases. In particular, the treatment of neuropathic pain represents a serious public health issue because currently available analgesia is ineffective in many cases or it has adverse effects. Treatment of pain-related suffering requires knowledge of how pain signals are initially generated and subsequently transmitted by the nervous system. A nociceptive system plays a key role in this process of encoding and transmission of pain signals. Modulation of the nociceptive synaptic transmission in the spinal cord dorsal horn represents an important mechanism in the development and maintenance of different pathological pain states. This doctoral thesis has aimed to investigate and clarify some of the mechanisms involved in the modulation of the spinal nociceptive processing in different pain states. The main attention was paid to study the following issues: (I.) Which is the role of Transient Receptor Potential Vanilloid type 1 channels (TRPV1), Toll-Like Receptors 4 (TLR4), and phosphatidylinositol 3-kinase (PI3K) in the development of neuropathic pain induced by paclitaxel (PAC) chemotherapy in acute in vitro, and subchronic in vivo murine model of PAC-induced peripheral neuropathy (PIPN)? (II.) How is affected spinal inhibitory synaptic control...
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The role of TRPV1 receptors in chemokine CCL2 induced modulation of nociceptive synaptic transmission at spinal cord level
Adámek, Pavel ; Paleček, Jiří (advisor) ; Krůšek, Jan (referee)
Modulation of nociceptive synaptic transmission in the spinal cord dorsal horn is a significant mechanism in the development and maintenance of different pathological pain states. Accumulating evidence indicates that the TRPV1 (transient receptor potential vanilloid 1) receptor and chemokine CCL2 (C-C motif ligand 2) may play a critical role in this process. The aim of this diploma thesis was to investigate the CCL2 induced modulation of nociceptive synaptic transmission in the dorsal horn of spinal cord and the role of the TRPV1 receptors. To investigate this aim patch-clamp recordings of spontaneous and miniature excitatory postsynaptic currents (sEPSC, mEPSC) from superficial dorsal horn neurons in acute rat lumbar spinal cord slices were used. After acute application of CCL2 on the slice preparation from naïve animals, a frequency increase of both sEPSC and mEPSC was present. This CCL2 induced increase in both sEPSC and mEPSC frequency was prevented by the TRPV1 receptor antagonist SB366791 application. No changes were observed in the amplitudes of sEPSC or mEPSC after application of the CCL2, SB366791, or co-application of CCL2 and SB366791. This suggests that the observed changes were mediated predominantly by presynaptic mechanisms. The preliminary results indicate that after chronic constriction...
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The role of nociceptive synaptic transmission modulation at the spinal cord level in different pain states
Adámek, Pavel
Pain is a common symptom of many clinical syndromes and diseases. In particular, the treatment of neuropathic pain represents a serious public health issue because currently available analgesia is ineffective in many cases or it has adverse effects. Treatment of pain-related suffering requires knowledge of how pain signals are initially generated and subsequently transmitted by the nervous system. A nociceptive system plays a key role in this process of encoding and transmission of pain signals. Modulation of the nociceptive synaptic transmission in the spinal cord dorsal horn represents an important mechanism in the development and maintenance of different pathological pain states. This doctoral thesis has aimed to investigate and clarify some of the mechanisms involved in the modulation of the spinal nociceptive processing in different pain states. The main attention was paid to study the following issues: (I.) Which is the role of Transient Receptor Potential Vanilloid type 1 channels (TRPV1), Toll-Like Receptors 4 (TLR4), and phosphatidylinositol 3-kinase (PI3K) in the development of neuropathic pain induced by paclitaxel (PAC) chemotherapy in acute in vitro, and subchronic in vivo murine model of PAC-induced peripheral neuropathy (PIPN)? (II.) How is affected spinal inhibitory synaptic control...
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The role of nociceptive synaptic transmission modulation at the spinal cord level in different pain states
Adámek, Pavel
Pain is a common symptom of many clinical syndromes and diseases. In particular, the treatment of neuropathic pain represents a serious public health issue because currently available analgesia is ineffective in many cases or it has adverse effects. Treatment of pain-related suffering requires knowledge of how pain signals are initially generated and subsequently transmitted by the nervous system. A nociceptive system plays a key role in this process of encoding and transmission of pain signals. Modulation of the nociceptive synaptic transmission in the spinal cord dorsal horn represents an important mechanism in the development and maintenance of different pathological pain states. This doctoral thesis has aimed to investigate and clarify some of the mechanisms involved in the modulation of the spinal nociceptive processing in different pain states. The main attention was paid to study the following issues: (I.) Which is the role of Transient Receptor Potential Vanilloid type 1 channels (TRPV1), Toll-Like Receptors 4 (TLR4), and phosphatidylinositol 3-kinase (PI3K) in the development of neuropathic pain induced by paclitaxel (PAC) chemotherapy in acute in vitro, and subchronic in vivo murine model of PAC-induced peripheral neuropathy (PIPN)? (II.) How is affected spinal inhibitory synaptic control...
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|
|
Neurosteroid effects on intracellular calcium and excitotoxicity
Naimová, Žaneta ; Smejkalová, Terézia (advisor) ; Adámek, Pavel (referee)
NMDA receptors belong to the family of ionotropic glutamate receptors, and are involved in synaptic plasticity, learning and memory. However, overactivation by the agonist glutamate can lead to neuronal death - excitotoxicity. Exitotoxicity is a result of excessive calcium influx into the cell through NMDA receptors, and is associated with many cental nervous system (CNS) diseases. Neurosteroids are endogenous compounds capable of NMDA receptor modulation, thus they may have pharmacological potential in the treatment of CNS disorders. The aim of this work was to investigate how pregnanolone sulfate (PA-S) and pregnanolone hemipimelate (PA-hPim) influence somatic calcium and excitotoxicity. We used fluorescence microscopy for recording changes in somatic calcium concentration. We observed that PA-S had no influence on relative somatic calcium concentration. Synthetic analog PA-hPim increased somatic calcium levels slightly. Next, we used oxygen-glucose deprivation (OGD) in vitro to study the influence of neurosteroids on excitotoxicity. Both PA-S and PA-hPim were neuroprotective in the model of acute OGD in vitro. Moreover, PA-S or PA-hPim pretreatment induced ischemic tolerance to a subsequent OGD episode. Our results suggest that neurosteroids PA-S and PA-hPim are potential candidates for the development...
|
|
|
The role of nociceptive synaptic transmission modulation at the spinal cord level in different pain states
Adámek, Pavel ; Paleček, Jiří (advisor) ; Vaculín, Šimon (referee) ; Vlachová, Viktorie (referee)
Pain is a common symptom of many clinical syndromes and diseases. In particular, the treatment of neuropathic pain represents a serious public health issue because currently available analgesia is ineffective in many cases or it has adverse effects. Treatment of pain-related suffering requires knowledge of how pain signals are initially generated and subsequently transmitted by the nervous system. A nociceptive system plays a key role in this process of encoding and transmission of pain signals. Modulation of the nociceptive synaptic transmission in the spinal cord dorsal horn represents an important mechanism in the development and maintenance of different pathological pain states. This doctoral thesis has aimed to investigate and clarify some of the mechanisms involved in the modulation of the spinal nociceptive processing in different pain states. The main attention was paid to study the following issues: (I.) Which is the role of Transient Receptor Potential Vanilloid type 1 channels (TRPV1), Toll-Like Receptors 4 (TLR4), and phosphatidylinositol 3-kinase (PI3K) in the development of neuropathic pain induced by paclitaxel (PAC) chemotherapy in acute in vitro, and subchronic in vivo murine model of PAC-induced peripheral neuropathy (PIPN)? (II.) How is affected spinal inhibitory synaptic control...
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The role of TRPV1 receptors in chemokine CCL2 induced modulation of nociceptive synaptic transmission at spinal cord level
Adámek, Pavel ; Paleček, Jiří (advisor) ; Krůšek, Jan (referee)
Modulation of nociceptive synaptic transmission in the spinal cord dorsal horn is a significant mechanism in the development and maintenance of different pathological pain states. Accumulating evidence indicates that the TRPV1 (transient receptor potential vanilloid 1) receptor and chemokine CCL2 (C-C motif ligand 2) may play a critical role in this process. The aim of this diploma thesis was to investigate the CCL2 induced modulation of nociceptive synaptic transmission in the dorsal horn of spinal cord and the role of the TRPV1 receptors. To investigate this aim patch-clamp recordings of spontaneous and miniature excitatory postsynaptic currents (sEPSC, mEPSC) from superficial dorsal horn neurons in acute rat lumbar spinal cord slices were used. After acute application of CCL2 on the slice preparation from naïve animals, a frequency increase of both sEPSC and mEPSC was present. This CCL2 induced increase in both sEPSC and mEPSC frequency was prevented by the TRPV1 receptor antagonist SB366791 application. No changes were observed in the amplitudes of sEPSC or mEPSC after application of the CCL2, SB366791, or co-application of CCL2 and SB366791. This suggests that the observed changes were mediated predominantly by presynaptic mechanisms. The preliminary results indicate that after chronic constriction...
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