{"id":{"repo_id":"aachen","oai_identifier":"oai:publications.rwth-aachen.de:51651"},"canonical_url":"https://search.dev.ndltd.org/etd/aachen/oai:publications.rwth-aachen.de:51651","repository":{"repo_id":"aachen","name":"RWTH Aachen University","base_url":"https://publications.rwth-aachen.de/oai2d"},"display":{"title":"Computations of object motion in the visual cortex of the ferret","abstract":"For living in a world in motion it is important to perceive and process motion of objects and predict their position along a motion trajectory. The image of the stimulus will move across the retina when viewing a moving stimulus with eyes fixed. Since the visual cortex is retinotopically organized the cortical representations can be expected to move accordingly. In this study we investigated the population membrane potential (PMP) and spiking activity (SA) of the neurons in the visual cortex of 6 adult female ferrets in response to natural stimulation. Up- and downwards moving white squares on a random dot background were presented to the anaesthetized animal on a computer screen. A stationary white square served as control. Visual Ares 17, 18, 19 and 21 were stained with a Voltage Sensitive Dye (VSD) and imaged with a photodiode array camera. Multi unit activity (MUA) was recorded in the same areas. After the experiments the brains were sectioned and stained for cell bodies and cytochrome oxidase to reconstruct area borders. Responses to visual stimuli in the VSD and electrophysiology signal were processed with MatlabR to investigate PMP and SA. When presenting a contrast square at the center of visual field it was mapped to the crossing of the vertical and horizontal meridian in areas 17/18. This resulted in changes of PMP and SA. When recording electrophysiologically and with VSD at the initial representation the response onset timing showed no significant difference for stationary as opposed to moving stimuli. Neither did the response onset timing of the PMP at the initial locus differ from that of the MUA. The VSD recordings showed a second stimulus representation site at the crossing of the vertical and horizontal meridian at the 19/21 border. The response onset for the population membrane potentials at the second representation site was significantly later than at the 17/18-border for the upwards-moving square but not for the downwards moving or the stationary square. Due to sparse firing of the multi units in higher order areas the second representation could not be detected electrophysiologically. PMP and MUA showed a successive increase of response onset latencies along the cortical representation of the motion trajectory in areas 17 and 18. Onset latency increased at positions medial to the initial representation for downwards moving stimuli and lateral to the initial representation for upwards moving stimuli. A successive increase of response onset latencies of population membrane potential along the motion trajectory at the 19/21 border was seen for the upwards moving and downwards moving square. However, this second representation appeared not to move in accordance with the first one. As expected from the retinotopic organization of areas 17, 18, 19 and 21 (Manger et al, 2002) a representation of stimuli presented in the center of visual field appeared at the 17/18 and 19/21 border. The lack of latency difference for response onsets to moving and stationary stimuli was unexpected. More experiments would have to be done to allow a more detailed analysis of onset latencies. Since VSD imaging gives information about PMP in layers I to III only (Grinvald and Hildesheim, 2004) one would expect response onsets to show longer latencies than those of action potentials due to synaptic input to layer IV neurons. It was not possible to reconstruct the exact depth of the electrophysiological recording sites after the experiments so no definite statement can be made about the origin of the spiking activity. Action potentials in supra- or infragranular layers might very well occur with latencies similar to the PMP in layer I to III. Given the anatomical connections of the visual system one might expect the latency for the response onset in areas 19 and 21 to be higher than for areas 17 and 18 for all conditions. However, the strict hierarchical model of processing in the visual cortex seems to be obsolete. In a study by Schroeder et al. (1998) it has been described that moving stimuli excite higher order areas sensitive to motion with latencies similar to those detected in V1. More experiments would have to be done to further explore the population dynamics and to more accurately map SA in higher order areas. The subsequent increase of response latency at recording positions along the motion trajectory in areas 17/18 for both SA and PMP was as expected given the retinotopic organization of the visual cortex (Manger et al., 2002). A moving representation at the 19/21 was expected in accordance with the one in areas 17/18. The fact that it was less obvious might be due to the later stage of processing and the larger receptive fields of neurons in higher order areas. It would be interesting to extend the recording sites for both SA and PMP to the posterior suprasylvian area that is said to be a motion sensitive area in the ferret visual cortex (Philip et al., 2006).","abstract_html":"For living in a world in motion it is important to perceive and process motion of objects and predict their position along a motion trajectory. The image of the stimulus will move across the retina when viewing a moving stimulus with eyes fixed. Since the visual cortex is retinotopically organized the cortical representations can be expected to move accordingly. In this study we investigated the population membrane potential (PMP) and spiking activity (SA) of the neurons in the visual cortex of 6 adult female ferrets in response to natural stimulation. Up- and downwards moving white squares on a random dot background were presented to the anaesthetized animal on a computer screen. A stationary white square served as control. Visual Ares 17, 18, 19 and 21 were stained with a Voltage Sensitive Dye (VSD) and imaged with a photodiode array camera. Multi unit activity (MUA) was recorded in the same areas. After the experiments the brains were sectioned and stained for cell bodies and cytochrome oxidase to reconstruct area borders. Responses to visual stimuli in the VSD and electrophysiology signal were processed with MatlabR to investigate PMP and SA. When presenting a contrast square at the center of visual field it was mapped to the crossing of the vertical and horizontal meridian in areas 17/18. This resulted in changes of PMP and SA. When recording electrophysiologically and with VSD at the initial representation the response onset timing showed no significant difference for stationary as opposed to moving stimuli. Neither did the response onset timing of the PMP at the initial locus differ from that of the MUA. The VSD recordings showed a second stimulus representation site at the crossing of the vertical and horizontal meridian at the 19/21 border. The response onset for the population membrane potentials at the second representation site was significantly later than at the 17/18-border for the upwards-moving square but not for the downwards moving or the stationary square. Due to sparse firing of the multi units in higher order areas the second representation could not be detected electrophysiologically. PMP and MUA showed a successive increase of response onset latencies along the cortical representation of the motion trajectory in areas 17 and 18. Onset latency increased at positions medial to the initial representation for downwards moving stimuli and lateral to the initial representation for upwards moving stimuli. A successive increase of response onset latencies of population membrane potential along the motion trajectory at the 19/21 border was seen for the upwards moving and downwards moving square. However, this second representation appeared not to move in accordance with the first one. As expected from the retinotopic organization of areas 17, 18, 19 and 21 (Manger et al, 2002) a representation of stimuli presented in the center of visual field appeared at the 17/18 and 19/21 border. The lack of latency difference for response onsets to moving and stationary stimuli was unexpected. More experiments would have to be done to allow a more detailed analysis of onset latencies. Since VSD imaging gives information about PMP in layers I to III only (Grinvald and Hildesheim, 2004) one would expect response onsets to show longer latencies than those of action potentials due to synaptic input to layer IV neurons. It was not possible to reconstruct the exact depth of the electrophysiological recording sites after the experiments so no definite statement can be made about the origin of the spiking activity. Action potentials in supra- or infragranular layers might very well occur with latencies similar to the PMP in layer I to III. Given the anatomical connections of the visual system one might expect the latency for the response onset in areas 19 and 21 to be higher than for areas 17 and 18 for all conditions. However, the strict hierarchical model of processing in the visual cortex seems to be obsolete. In a study by Schroeder et al. (1998) it has been described that moving stimuli excite higher order areas sensitive to motion with latencies similar to those detected in V1. More experiments would have to be done to further explore the population dynamics and to more accurately map SA in higher order areas. The subsequent increase of response latency at recording positions along the motion trajectory in areas 17/18 for both SA and PMP was as expected given the retinotopic organization of the visual cortex (Manger et al., 2002). A moving representation at the 19/21 was expected in accordance with the one in areas 17/18. The fact that it was less obvious might be due to the later stage of processing and the larger receptive fields of neurons in higher order areas. It would be interesting to extend the recording sites for both SA and PMP to the posterior suprasylvian area that is said to be a motion sensitive area in the ferret visual cortex (Philip et al., 2006).","abstract_has_math":false,"creators":["Wehner, Sarah"],"institution":"Publikationsserver der RWTH Aachen University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Amunts, Katrin"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2009,"date_issued":"2009","date_published":"2009","updated_at":"2026-07-30T19:40:42Z","subjects":["info:eu-repo/classification/ddc/610","Sehrinde","Medizin","Objektbewegung","visueller Kortex","object motion","visual cortex"],"languages":["eng"],"rights":["info:eu-repo/semantics/openAccess"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-113921%22"],"render_values":[{"text":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-113921%22","href":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-113921%22","code":true}]}]},"links":{"outbound_url":"https://publications.rwth-aachen.de/record/51651","outbound_label":"Repository record","outbound_source":"dc:identifier"},"source_record":{"url":"https://publications.rwth-aachen.de/oai2d?verb=GetRecord&metadataPrefix=oai_dc&identifier=oai%3Apublications.rwth-aachen.de%3A51651","prefix":"oai_dc"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Amunts, Katrin"]},{"key":"dc:creator","label":"Author","values":["Wehner, Sarah"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:coverage","label":"Dc Coverage","values":["DE"]},{"key":"dc:date","label":"Dc Date","values":["2009"]},{"key":"dc:publisher","label":"Institution","values":["Publikationsserver der RWTH Aachen University"]},{"key":"dc:relation","label":"Dc Relation","values":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-31072"]},{"key":"dc:type","label":"Dc Type","values":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["info:eu-repo/classification/ddc/610","Sehrinde","Medizin","Objektbewegung","visueller Kortex","object motion","visual cortex"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["info:eu-repo/semantics/openAccess"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/record/51651","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-113921%22"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["For living in a world in motion it is important to perceive and process motion of objects and predict their position along a motion trajectory. The image of the stimulus will move across the retina when viewing a moving stimulus with eyes fixed. Since the visual cortex is retinotopically organized the cortical representations can be expected to move accordingly. In this study we investigated the population membrane potential (PMP) and spiking activity (SA) of the neurons in the visual cortex of 6 adult female ferrets in response to natural stimulation. Up- and downwards moving white squares on a random dot background were presented to the anaesthetized animal on a computer screen. A stationary white square served as control. Visual Ares 17, 18, 19 and 21 were stained with a Voltage Sensitive Dye (VSD) and imaged with a photodiode array camera. Multi unit activity (MUA) was recorded in the same areas. After the experiments the brains were sectioned and stained for cell bodies and cytochrome oxidase to reconstruct area borders. Responses to visual stimuli in the VSD and electrophysiology signal were processed with MatlabR to investigate PMP and SA. When presenting a contrast square at the center of visual field it was mapped to the crossing of the vertical and horizontal meridian in areas 17/18. This resulted in changes of PMP and SA. When recording electrophysiologically and with VSD at the initial representation the response onset timing showed no significant difference for stationary as opposed to moving stimuli. Neither did the response onset timing of the PMP at the initial locus differ from that of the MUA. The VSD recordings showed a second stimulus representation site at the crossing of the vertical and horizontal meridian at the 19/21 border. The response onset for the population membrane potentials at the second representation site was significantly later than at the 17/18-border for the upwards-moving square but not for the downwards moving or the stationary square. Due to sparse firing of the multi units in higher order areas the second representation could not be detected electrophysiologically. PMP and MUA showed a successive increase of response onset latencies along the cortical representation of the motion trajectory in areas 17 and 18. Onset latency increased at positions medial to the initial representation for downwards moving stimuli and lateral to the initial representation for upwards moving stimuli. A successive increase of response onset latencies of population membrane potential along the motion trajectory at the 19/21 border was seen for the upwards moving and downwards moving square. However, this second representation appeared not to move in accordance with the first one. As expected from the retinotopic organization of areas 17, 18, 19 and 21 (Manger et al, 2002) a representation of stimuli presented in the center of visual field appeared at the 17/18 and 19/21 border. The lack of latency difference for response onsets to moving and stationary stimuli was unexpected. More experiments would have to be done to allow a more detailed analysis of onset latencies. Since VSD imaging gives information about PMP in layers I to III only (Grinvald and Hildesheim, 2004) one would expect response onsets to show longer latencies than those of action potentials due to synaptic input to layer IV neurons. It was not possible to reconstruct the exact depth of the electrophysiological recording sites after the experiments so no definite statement can be made about the origin of the spiking activity. Action potentials in supra- or infragranular layers might very well occur with latencies similar to the PMP in layer I to III. Given the anatomical connections of the visual system one might expect the latency for the response onset in areas 19 and 21 to be higher than for areas 17 and 18 for all conditions. However, the strict hierarchical model of processing in the visual cortex seems to be obsolete. In a study by Schroeder et al. (1998) it has been described that moving stimuli excite higher order areas sensitive to motion with latencies similar to those detected in V1. More experiments would have to be done to further explore the population dynamics and to more accurately map SA in higher order areas. The subsequent increase of response latency at recording positions along the motion trajectory in areas 17/18 for both SA and PMP was as expected given the retinotopic organization of the visual cortex (Manger et al., 2002). A moving representation at the 19/21 was expected in accordance with the one in areas 17/18. The fact that it was less obvious might be due to the later stage of processing and the larger receptive fields of neurons in higher order areas. It would be interesting to extend the recording sites for both SA and PMP to the posterior suprasylvian area that is said to be a motion sensitive area in the ferret visual cortex (Philip et al., 2006)."]},{"key":"dc:source","label":"Dc Source","values":["Aachen : Publikationsserver der RWTH Aachen University 66 S. : Ill., graph. Darst. (2009). = Aachen, Techn. Hochsch., Diss., 2009"]},{"key":"dc:title","label":"Title","values":["Computations of object motion in the visual cortex of the ferret"]}]}],"canonical_facts":{"dc:contributor":["Amunts, Katrin"],"dc:coverage":["DE"],"dc:creator":["Wehner, Sarah"],"dc:date":["2009"],"dc:description":["For living in a world in motion it is important to perceive and process motion of objects and predict their position along a motion trajectory. The image of the stimulus will move across the retina when viewing a moving stimulus with eyes fixed. Since the visual cortex is retinotopically organized the cortical representations can be expected to move accordingly. In this study we investigated the population membrane potential (PMP) and spiking activity (SA) of the neurons in the visual cortex of 6 adult female ferrets in response to natural stimulation. Up- and downwards moving white squares on a random dot background were presented to the anaesthetized animal on a computer screen. A stationary white square served as control. Visual Ares 17, 18, 19 and 21 were stained with a Voltage Sensitive Dye (VSD) and imaged with a photodiode array camera. Multi unit activity (MUA) was recorded in the same areas. After the experiments the brains were sectioned and stained for cell bodies and cytochrome oxidase to reconstruct area borders. Responses to visual stimuli in the VSD and electrophysiology signal were processed with MatlabR to investigate PMP and SA. When presenting a contrast square at the center of visual field it was mapped to the crossing of the vertical and horizontal meridian in areas 17/18. This resulted in changes of PMP and SA. When recording electrophysiologically and with VSD at the initial representation the response onset timing showed no significant difference for stationary as opposed to moving stimuli. Neither did the response onset timing of the PMP at the initial locus differ from that of the MUA. The VSD recordings showed a second stimulus representation site at the crossing of the vertical and horizontal meridian at the 19/21 border. The response onset for the population membrane potentials at the second representation site was significantly later than at the 17/18-border for the upwards-moving square but not for the downwards moving or the stationary square. Due to sparse firing of the multi units in higher order areas the second representation could not be detected electrophysiologically. PMP and MUA showed a successive increase of response onset latencies along the cortical representation of the motion trajectory in areas 17 and 18. Onset latency increased at positions medial to the initial representation for downwards moving stimuli and lateral to the initial representation for upwards moving stimuli. A successive increase of response onset latencies of population membrane potential along the motion trajectory at the 19/21 border was seen for the upwards moving and downwards moving square. However, this second representation appeared not to move in accordance with the first one. As expected from the retinotopic organization of areas 17, 18, 19 and 21 (Manger et al, 2002) a representation of stimuli presented in the center of visual field appeared at the 17/18 and 19/21 border. The lack of latency difference for response onsets to moving and stationary stimuli was unexpected. More experiments would have to be done to allow a more detailed analysis of onset latencies. Since VSD imaging gives information about PMP in layers I to III only (Grinvald and Hildesheim, 2004) one would expect response onsets to show longer latencies than those of action potentials due to synaptic input to layer IV neurons. It was not possible to reconstruct the exact depth of the electrophysiological recording sites after the experiments so no definite statement can be made about the origin of the spiking activity. Action potentials in supra- or infragranular layers might very well occur with latencies similar to the PMP in layer I to III. Given the anatomical connections of the visual system one might expect the latency for the response onset in areas 19 and 21 to be higher than for areas 17 and 18 for all conditions. However, the strict hierarchical model of processing in the visual cortex seems to be obsolete. In a study by Schroeder et al. (1998) it has been described that moving stimuli excite higher order areas sensitive to motion with latencies similar to those detected in V1. More experiments would have to be done to further explore the population dynamics and to more accurately map SA in higher order areas. The subsequent increase of response latency at recording positions along the motion trajectory in areas 17/18 for both SA and PMP was as expected given the retinotopic organization of the visual cortex (Manger et al., 2002). A moving representation at the 19/21 was expected in accordance with the one in areas 17/18. The fact that it was less obvious might be due to the later stage of processing and the larger receptive fields of neurons in higher order areas. It would be interesting to extend the recording sites for both SA and PMP to the posterior suprasylvian area that is said to be a motion sensitive area in the ferret visual cortex (Philip et al., 2006)."],"dc:identifier":["https://publications.rwth-aachen.de/record/51651","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-113921%22"],"dc:language":["eng"],"dc:publisher":["Publikationsserver der RWTH Aachen University"],"dc:relation":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-31072"],"dc:rights":["info:eu-repo/semantics/openAccess"],"dc:source":["Aachen : Publikationsserver der RWTH Aachen University 66 S. : Ill., graph. Darst. (2009). = Aachen, Techn. 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