{"id":{"repo_id":"kings","oai_identifier":"oai:kclpure.kcl.ac.uk:studenttheses/055c4407-fb25-436a-91f6-e5fdf2fb42d1"},"canonical_url":"https://search.dev.ndltd.org/etd/kings/oai:kclpure.kcl.ac.uk:studenttheses/055c4407-fb25-436a-91f6-e5fdf2fb42d1","repository":{"repo_id":"kings","name":"King's College London","base_url":"https://kclpure.kcl.ac.uk/ws/oai"},"display":{"title":"Molecular regulation of neuroblast migration in the postnatal brain","abstract":"The subventricular zone (SVZ) is one of the main neurogenic niches in the postnatal<br/>brain. Neural precursors derived from SVZ stem cells migrate in chains to the<br/>olfactory bulb (OB) via the rostral migratory stream (RMS) through channels (glial<br/>tubes) formed by the processes of astrocytes. Importantly, these precursors have<br/>the capacity to migrate away from their native route to areas of pathological<br/>damage in the adult brain. Therefore, studying the migratory properties of these<br/>cells is essential, not only to understand basic aspects of adult neurogenesis, but<br/>also to exploit the potential of adult neural stem cells in neuroregenerative<br/>strategies. Whilst considerable progress has been made in the field of SVZ neural<br/>precursor migration, the exact molecular mechanisms regulating this process<br/>remain to be fully elucidated.<br/><br/>The endocannabinoid system is known to play an important role in the regulation of<br/>neural stem cell proliferation. Here, we show that CB signalling also regulates the<br/>migration of SVZ-derived neural precursors. In addition, stimulation of G-protein<br/>coupled cannabinoid receptors, CB1 and CB2, leads to significant activation of RalA,<br/>a Ras-like GTPase involved in the control of neuronal morphology and polarity.<br/>siRNA-mediated knockdown of RalA or the expression of dominant negative RalA<br/>abolished cannabinoid-induced stimulation of migration. Time-lapse imaging<br/>revealed that depletion of RalA strongly impaired nucleokinesis: a crucial step for<br/>efficient migration. Analysis of RalA function in vivo, using wild type and mutant<br/>constructs electroporated into the SVZ, showed that the loss of RalA function<br/>results in both altered morphology and direction of migration. Finally, selective<br/>deletion of RalA in RMS neuroblasts in vivo further confirms that RalA is required<br/>for correct polarised morphology of migrating neuroblasts in the RMS.<br/><br/>In summary, RalA is activated by CB agonists, and is required for CB-promoted<br/>migration of RMS neuroblasts. Furthermore, RalA expression is necessary for<br/>polarised morphology and efficient migration of RMS neuroblasts both in vitro and<br/>in vivo.","abstract_html":"The subventricular zone (SVZ) is one of the main neurogenic niches in the postnatal&lt;br/&gt;brain. Neural precursors derived from SVZ stem cells migrate in chains to the&lt;br/&gt;olfactory bulb (OB) via the rostral migratory stream (RMS) through channels (glial&lt;br/&gt;tubes) formed by the processes of astrocytes. Importantly, these precursors have&lt;br/&gt;the capacity to migrate away from their native route to areas of pathological&lt;br/&gt;damage in the adult brain. Therefore, studying the migratory properties of these&lt;br/&gt;cells is essential, not only to understand basic aspects of adult neurogenesis, but&lt;br/&gt;also to exploit the potential of adult neural stem cells in neuroregenerative&lt;br/&gt;strategies. Whilst considerable progress has been made in the field of SVZ neural&lt;br/&gt;precursor migration, the exact molecular mechanisms regulating this process&lt;br/&gt;remain to be fully elucidated.&lt;br/&gt;&lt;br/&gt;The endocannabinoid system is known to play an important role in the regulation of&lt;br/&gt;neural stem cell proliferation. Here, we show that CB signalling also regulates the&lt;br/&gt;migration of SVZ-derived neural precursors. In addition, stimulation of G-protein&lt;br/&gt;coupled cannabinoid receptors, CB1 and CB2, leads to significant activation of RalA,&lt;br/&gt;a Ras-like GTPase involved in the control of neuronal morphology and polarity.&lt;br/&gt;siRNA-mediated knockdown of RalA or the expression of dominant negative RalA&lt;br/&gt;abolished cannabinoid-induced stimulation of migration. Time-lapse imaging&lt;br/&gt;revealed that depletion of RalA strongly impaired nucleokinesis: a crucial step for&lt;br/&gt;efficient migration. Analysis of RalA function in vivo, using wild type and mutant&lt;br/&gt;constructs electroporated into the SVZ, showed that the loss of RalA function&lt;br/&gt;results in both altered morphology and direction of migration. Finally, selective&lt;br/&gt;deletion of RalA in RMS neuroblasts in vivo further confirms that RalA is required&lt;br/&gt;for correct polarised morphology of migrating neuroblasts in the RMS.&lt;br/&gt;&lt;br/&gt;In summary, RalA is activated by CB agonists, and is required for CB-promoted&lt;br/&gt;migration of RMS neuroblasts. Furthermore, RalA expression is necessary for&lt;br/&gt;polarised morphology and efficient migration of RMS neuroblasts both in vitro and&lt;br/&gt;in vivo.","abstract_has_math":false,"creators":["Gajendra, Sangeetha"],"institution":"King's College London","degree_name":"Doctor of Philosophy","degree_level":"Doctoral Thesis","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Doherty, Patrick","Lalli, Giovanna"],"committee_chairs":[],"committee_members":[],"year":2013,"date_issued":"2013-1-1","date_published":"2013-1-1","updated_at":"2026-07-24T02:44:31Z","subjects":[],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["oai:kclpure.kcl.ac.uk:studenttheses/055c4407-fb25-436a-91f6-e5fdf2fb42d1"],"render_values":[{"text":"oai:kclpure.kcl.ac.uk:studenttheses/055c4407-fb25-436a-91f6-e5fdf2fb42d1","href":null,"code":true}]}]},"links":{"outbound_url":"https://kclpure.kcl.ac.uk/portal/en/studentTheses/055c4407-fb25-436a-91f6-e5fdf2fb42d1","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Doherty, Patrick","Lalli, Giovanna"]},{"key":"dc:creator","label":"Author","values":["Gajendra, Sangeetha"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2013-1-1"]},{"key":"dc:date.issued","label":"Date","values":["2013-1-1"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["King's College London"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://kclpure.kcl.ac.uk/portal/en/studentTheses/055c4407-fb25-436a-91f6-e5fdf2fb42d1"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Doctoral Thesis"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["Doctor of Philosophy"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["oai:kclpure.kcl.ac.uk:studenttheses/055c4407-fb25-436a-91f6-e5fdf2fb42d1","https://kclpure.kcl.ac.uk/portal/en/studentTheses/055c4407-fb25-436a-91f6-e5fdf2fb42d1"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://kclpure.kcl.ac.uk/portal/files/12608250/2013_Gajendra_Sangeetha_0204924_ethesis.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The subventricular zone (SVZ) is one of the main neurogenic niches in the postnatal<br/>brain. Neural precursors derived from SVZ stem cells migrate in chains to the<br/>olfactory bulb (OB) via the rostral migratory stream (RMS) through channels (glial<br/>tubes) formed by the processes of astrocytes. Importantly, these precursors have<br/>the capacity to migrate away from their native route to areas of pathological<br/>damage in the adult brain. Therefore, studying the migratory properties of these<br/>cells is essential, not only to understand basic aspects of adult neurogenesis, but<br/>also to exploit the potential of adult neural stem cells in neuroregenerative<br/>strategies. Whilst considerable progress has been made in the field of SVZ neural<br/>precursor migration, the exact molecular mechanisms regulating this process<br/>remain to be fully elucidated.<br/><br/>The endocannabinoid system is known to play an important role in the regulation of<br/>neural stem cell proliferation. Here, we show that CB signalling also regulates the<br/>migration of SVZ-derived neural precursors. In addition, stimulation of G-protein<br/>coupled cannabinoid receptors, CB1 and CB2, leads to significant activation of RalA,<br/>a Ras-like GTPase involved in the control of neuronal morphology and polarity.<br/>siRNA-mediated knockdown of RalA or the expression of dominant negative RalA<br/>abolished cannabinoid-induced stimulation of migration. Time-lapse imaging<br/>revealed that depletion of RalA strongly impaired nucleokinesis: a crucial step for<br/>efficient migration. Analysis of RalA function in vivo, using wild type and mutant<br/>constructs electroporated into the SVZ, showed that the loss of RalA function<br/>results in both altered morphology and direction of migration. Finally, selective<br/>deletion of RalA in RMS neuroblasts in vivo further confirms that RalA is required<br/>for correct polarised morphology of migrating neuroblasts in the RMS.<br/><br/>In summary, RalA is activated by CB agonists, and is required for CB-promoted<br/>migration of RMS neuroblasts. Furthermore, RalA expression is necessary for<br/>polarised morphology and efficient migration of RMS neuroblasts both in vitro and<br/>in vivo."]},{"key":"dc:title","label":"Title","values":["Molecular regulation of neuroblast migration in the postnatal brain"]}]}],"canonical_facts":{"dc:contributor.advisor":["Doherty, Patrick","Lalli, Giovanna"],"dc:creator":["Gajendra, Sangeetha"],"dc:date":["2013-1-1"],"dc:date.issued":["2013-1-1"],"dc:description.abstract":["The subventricular zone (SVZ) is one of the main neurogenic niches in the postnatal<br/>brain. Neural precursors derived from SVZ stem cells migrate in chains to the<br/>olfactory bulb (OB) via the rostral migratory stream (RMS) through channels (glial<br/>tubes) formed by the processes of astrocytes. Importantly, these precursors have<br/>the capacity to migrate away from their native route to areas of pathological<br/>damage in the adult brain. Therefore, studying the migratory properties of these<br/>cells is essential, not only to understand basic aspects of adult neurogenesis, but<br/>also to exploit the potential of adult neural stem cells in neuroregenerative<br/>strategies. Whilst considerable progress has been made in the field of SVZ neural<br/>precursor migration, the exact molecular mechanisms regulating this process<br/>remain to be fully elucidated.<br/><br/>The endocannabinoid system is known to play an important role in the regulation of<br/>neural stem cell proliferation. Here, we show that CB signalling also regulates the<br/>migration of SVZ-derived neural precursors. In addition, stimulation of G-protein<br/>coupled cannabinoid receptors, CB1 and CB2, leads to significant activation of RalA,<br/>a Ras-like GTPase involved in the control of neuronal morphology and polarity.<br/>siRNA-mediated knockdown of RalA or the expression of dominant negative RalA<br/>abolished cannabinoid-induced stimulation of migration. Time-lapse imaging<br/>revealed that depletion of RalA strongly impaired nucleokinesis: a crucial step for<br/>efficient migration. Analysis of RalA function in vivo, using wild type and mutant<br/>constructs electroporated into the SVZ, showed that the loss of RalA function<br/>results in both altered morphology and direction of migration. Finally, selective<br/>deletion of RalA in RMS neuroblasts in vivo further confirms that RalA is required<br/>for correct polarised morphology of migrating neuroblasts in the RMS.<br/><br/>In summary, RalA is activated by CB agonists, and is required for CB-promoted<br/>migration of RMS neuroblasts. Furthermore, RalA expression is necessary for<br/>polarised morphology and efficient migration of RMS neuroblasts both in vitro and<br/>in vivo."],"dc:identifier":["oai:kclpure.kcl.ac.uk:studenttheses/055c4407-fb25-436a-91f6-e5fdf2fb42d1","https://kclpure.kcl.ac.uk/portal/en/studentTheses/055c4407-fb25-436a-91f6-e5fdf2fb42d1"],"dc:identifier.uri":["https://kclpure.kcl.ac.uk/portal/files/12608250/2013_Gajendra_Sangeetha_0204924_ethesis.pdf"],"dc:language":["eng"],"dc:publisher.institution":["King's College London"],"dc:relation.isreferencedby":["https://kclpure.kcl.ac.uk/portal/en/studentTheses/055c4407-fb25-436a-91f6-e5fdf2fb42d1"],"dc:title":["Molecular regulation of neuroblast migration in the postnatal brain"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["Doctoral Thesis"],"dc:type.qualificationname":["Doctor of Philosophy"]},"updated_at":"2026-07-24T02:44:31Z"}