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Effect of ketamine on light-induced changes in the circadian system
Kratina, Alex ; Bendová, Zdeňka (advisor) ; Valeš, Karel (referee)
The circadian system is controlled by the suprachiasmatic nuclei of the hypothalamus (SCN) and ensures optimal timing of physiological processes. Synchronization of this system with external light conditions is based on the activation of NMDA receptors during light exposure in the subjective night. Ketamine is a non-competitive antagonist of NMDA receptors used as a safe anesthetic, whose subanesthetic doses act as an antidepressant with a rapid onset of action, and increase proliferation in some parts of the brain. There are hypotheses about the possible effect of subanesthetic doses of ketamine on the circadian system, altough this effect has not yet been tested. This work aims to investigate the effect of a single subanesthetic dose of ketamine on the circadian system of the rat, especially on light-induced changes in locomotor activity and light-induced markers in the SCN and dentate gyrus, which represents one of the strongly proliferative areas of the brain. Our results show that ketamine decreases light pulse-induced c-FOS protein expression in the SCN at the onset of the subjective night, but increases this expression in the dentate gyrus under the same conditions. Reduction of c-FOS expression in the SCN correlates with the behavioral output of the circadian system and thus suppresses the...
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Functional differentiation in the hippocampus
Vondráková, Kateřina ; Telenský, Petr (advisor) ; Stuchlík, Aleš (referee)
This work has been focused on anatomical and functional differentiation of the hippocampus. Hippocampus, as one of the most studied structures in the brain has an irreplaceable role in encoding, consolidation and recall of memories. In the early 20th century, Ramon y Cajal has divided hippocampus into 3 subregions, Ammon's horn (CA1-CA3 region), dentate gyrus and subiculum. Diferences in gene expresion, principal cell features and organization of connections with other structures suggests further division of the hippocampus according to septo-temporal axis, into ventral, dorsal and intermedial zone. Most importantly, the efects of impairment or inactivation of the individual subregions of the hippocampus, allow us to determine their prospective functions.
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Functional differentiation in the hippocampus
Vondráková, Kateřina ; Telenský, Petr (advisor) ; Stuchlík, Aleš (referee)
This work has been focused on anatomical and functional differentiation of the hippocampus. Hippocampus, as one of the most studied structures in the brain has an irreplaceable role in encoding, consolidation and recall of memories. In the early 20th century, Ramon y Cajal has divided hippocampus into 3 subregions, Ammon's horn (CA1-CA3 region), dentate gyrus and subiculum. Diferences in gene expresion, principal cell features and organization of connections with other structures suggests further division of the hippocampus according to septo-temporal axis, into ventral, dorsal and intermedial zone. Most importantly, the efects of impairment or inactivation of the individual subregions of the hippocampus, allow us to determine their prospective functions.
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