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Evidence for the emergence of relative navigational responding in male C57BL/6J mice in a land-based task
Title
Evidence for the emergence of relative navigational responding in male C57BL/6J mice in a land-based task.
Creator
Lora, Joan C., Stackman, Robert W., Graduate College
Abstract/Description
We recently reported that male C57BL/6J mice navigate in spatial tasks, such as the Morris water maze MWM, by swimming in a particular direction to a location relative to poolbased cues, rather than to an absolute location defined by room-based cues. Neural mechanisms supporting this bias in rodents for relative responding rather than absolute responding in spatial tasks are not yet understood. Anterior thalamic neurons discharge according to the current directional heading of the animal. The...
Show moreWe recently reported that male C57BL/6J mice navigate in spatial tasks, such as the Morris water maze MWM, by swimming in a particular direction to a location relative to poolbased cues, rather than to an absolute location defined by room-based cues. Neural mechanisms supporting this bias in rodents for relative responding rather than absolute responding in spatial tasks are not yet understood. Anterior thalamic neurons discharge according to the current directional heading of the animal. The contribution of head direction HD cell activity to navigation has been difficult to elucidate. Selective inactivation of anterior thalamic nuclei ATN by microinfusion of muscimol or fluorophore-conjugated muscimol caused a near complete shift in preference from relative to absolute responding. Interestingly, inactivation of the dorsal CA1 region of the hippocampus did not affect relative responding. A land based version of the MWM has been developed to permit the recording of anterior thalamic HD cells during spatial search behavior. These experiments have been conducted to further examine the contribution of the HD cell activity to relative responding during spatial navigation.
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Date Issued
2014
PURL
http://purl.flvc.org/fau/fd/FA00005834
Format
Document (PDF)
Effects of hippocampal impairment on rodent spatial and non-spatial memory
Title
Effects of hippocampal impairment on rodent spatial and non-spatial memory.
Creator
Rios, Lisa, Lora, Joan C., Zhang, Gongliang, Stackman, Robert W., Graduate College
Date Issued
2011-04-08
PURL
http://purl.flvc.org/fcla/dt/3164769
Subject Headings
Nerve Degeneration, Rodents, Space perception
Format
Document (PDF)
Which Way is It? Spatial Navigation and the Genetics of Head Direction Cells
Title
Which Way is It? Spatial Navigation and the Genetics of Head Direction Cells.
Creator
Lora, Joan C., Stackman, Robert W., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Psychology
Abstract/Description
From locating a secure home, foraging for food, running away from predators, spatial navigation is an integral part of everyday life. Multiple brain regions work together to form a three-dimensional representation of our environment; specifically, place cells, grid cells, border cells & head direction cells are thought to interact and influence one another to form this cognitive map. Head direction (HD) cells fire as the animal moves through space, according to directional orientation of the...
Show moreFrom locating a secure home, foraging for food, running away from predators, spatial navigation is an integral part of everyday life. Multiple brain regions work together to form a three-dimensional representation of our environment; specifically, place cells, grid cells, border cells & head direction cells are thought to interact and influence one another to form this cognitive map. Head direction (HD) cells fire as the animal moves through space, according to directional orientation of the animal’s head with respect to the laboratory reference frame, and are therefore considered to represent the directional sense. Interestingly, inactivation of head direction cell-containing brain regions has mixed consequences on spatial behavior. Current methods of identifying HD cells are limited to in vivo electrophysiological recordings in a dry-land environment. We first developed a dry-land version of the MWM in order to carry out behavioral-recording paired studies. Additionally, to learn about HD cells function we quantified expression of neuronal activation marker (c-Fos), and L-amino acid transporter 4 (Lat4) in neurons found within the HD cell dense anterodorsal thalamic nucleus (ADN) in mice after exploratory behavior in an open field, or forward unidirectional movement on a treadmill. We hypothesize that the degree to which ADN neurons are activated during exploratory behavior is influenced by the range of heading directions sampled. Additionally, we hypothesize that c-Fos and Lat4 are colocalized within ADN neurons following varying amounts of head direction exposure. Results indicate that following free locomotion of mice in an open field arena, which permitted access to 360° of heading, a greater number of ADN neurons express c-Fos protein compared to those exposed to a limited range of head directions during locomotion in a treadmill. These findings suggest that the degree of ADN neuronal activation was dependent upon the range of head directions sampled. We observed a high degree of colocalization of c-Fos and Lat4 within ADN suggesting that Lat4 may be a useful tool to manipulate neuronal activity of HD cells. Identifying genetic markers specific to ADN helps provide an essential understanding of the spatial navigation system, and supports development of therapies for cognitive disorders affecting navigation.
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Date Issued
2017
PURL
http://purl.flvc.org/fau/fd/FA00004931, http://purl.flvc.org/fau/fd/FA00004931
Subject Headings
Psychobiology., Spatial behavior in animals., Mice as laboratory animals., Navigation--Psychological aspects., Computational intelligence.
Format
Document (PDF)