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Time- and gender- dependent differences in neuronal behaviors in culture

dc.contributor.advisorRizzoli, Silvio O. Prof. Dr.
dc.contributor.authorSertel, Sinem Meleknur
dc.date.accessioned2020-05-29T13:01:23Z
dc.date.available2021-05-11T00:50:23Z
dc.date.issued2020-05-29
dc.identifier.urihttp://hdl.handle.net/21.11130/00-1735-0000-0005-13BF-F
dc.identifier.urihttp://dx.doi.org/10.53846/goediss-8003
dc.identifier.urihttp://dx.doi.org/10.53846/goediss-8003
dc.language.isoengde
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/4.0/
dc.subject.ddc570de
dc.titleTime- and gender- dependent differences in neuronal behaviors in culturede
dc.typecumulativeThesisde
dc.contributor.refereeEhrenreich, Hannelore Prof. Dr. Dr.
dc.date.examination2020-05-13
dc.description.abstractengIsolating cells from a living organism and growing them in a Petri dish allowed scientists to study the physiology and biochemistry of healthy and diseased cells. Today we have cell cultures from almost any tissue type, including the brain. One brain region has been fundamental for understanding neuronal and synaptic dynamics, both in vivo and in culture: the hippocampus. Since the H.M. case, the hippocampus drew attention to itself with the promise of understanding molecular and electrical mechanisms behind learning and memory. This made the primary culture from hippocampus tissue one of the most commonly used models in the neuroscience field. Despite being a very common preparation, it is still imperfectly known. For example, during preparation, multiple animals are sacrificed, and tissues are pooled, regardless of their sex. That creates a female-male mixed culture in which the female to male neuron ratio is unknown. It is still unclear whether the neurons of different genders behave differently in these cultures. To address this question, I performed a systematic investigation on cultured female and male neurons. I found differences in their electrical activity as well as in their synaptic translation rate. First, I compared the firing rates with a calcium indicator and found higher spontaneous electrical activity and larger response capacity to electrical stimulation in male neurons than in female neurons. The following step was investigating the dynamics of synaptic compartments with a synaptotagmin 1 (Syt1) uptake assay. It also proved that male neurons have a larger active synaptic vesicle pool size and dynamics than female neurons. An immunostaining survey with a focus on synaptic proteins did not show major differences between the two sexes. Their transcriptomes also shown substantial differences. Finally, I also examined the local translation, and found higher translation rate at the male synapse, which could, at least in part, explain the functional differences. These results present an extensive comparison for functional behavior and synaptic structure between female and male neurons and encourage a first discussion on primary hippocampal culture preparation in respect to female-male neuron ratio. Another overlooked aspect of the primary hippocampal culture is the circadian effects on cellular biology. It is now well established that circadian rhythm is kept in every mammalian cell via the molecular clock, which consists of several transcription factors. However, without a central pacemaker, which in vivo is located in the suprachiasmatic nucleus (SCN) of the hypothalamus, it would be difficult to maintain a 24-hour rhythmicity in cell cultures. Therefore, we expect that primary hippocampal neurons in culture will maintain a form of rhythmus in culture, but this has never been studied. I performed a series of experiments indicating the existence of a weak circadian rhythm in the firing patterns, the synaptic activity and mRNA localization at the synapse, even after 20 day-long deprivation of external stimuli. I found a 2 rhythmically expressed transcript, RNA-binding motif 3 (RBM3), whose knock-down results in significant changes in the firing pattern and in the reduction of the active synaptic vesicle pool dynamics, the post-synapse size, and the post-synaptic translation rate. This implies that RBM3 is involved in sustaining the rhythmic abundance of synaptic proteins, and therefore in sustaining rhythmic synaptic function. Overall, these findings change the impression of the primary hippocampal culture. It is essential to be aware of the female-male ratio and the timing of experiments.de
dc.contributor.coRefereeBringmann, Henrik Prof. Dr.
dc.subject.engcircadian rhythmde
dc.subject.engsynaptic plasticityde
dc.subject.englocal translationde
dc.subject.engsexual differentiationde
dc.subject.engprimary hippocampal culturede
dc.identifier.urnurn:nbn:de:gbv:7-21.11130/00-1735-0000-0005-13BF-F-8
dc.affiliation.instituteGöttinger Graduiertenschule für Neurowissenschaften, Biophysik und molekulare Biowissenschaften (GGNB)de
dc.subject.gokfullBiologie (PPN619462639)de
dc.description.embargoed2021-05-11
dc.identifier.ppn1699071667


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