scholarly journals Dominance of the Proximal Coordinate Frame in Determining the Locations of Hippocampal Place Cell Activity During Navigation

2008 ◽  
Vol 99 (1) ◽  
pp. 60-76 ◽  
Author(s):  
Jennifer J. Siegel ◽  
Joshua P. Neunuebel ◽  
James J. Knierim
Keyword(s):  
Spatial Representation ◽  
Reference Frames ◽  
Specific Activity ◽  
Late Phase ◽  
Cell Activity ◽  
Coordinate Frame ◽  
Spatial Frames Of Reference ◽  
Preference Task ◽  
Freely Moving ◽  
Hippocampal Place Cell

The place-specific activity of hippocampal cells provides downstream structures with information regarding an animal's position within an environment and, perhaps, the location of goals within that environment. In rodents, recent research has suggested that distal cues primarily set the orientation of the spatial representation, whereas the boundaries of the behavioral apparatus determine the locations of place activity. The current study was designed to address possible biases in some previous research that may have minimized the likelihood of observing place activity bound to distal cues. Hippocampal single-unit activity was recorded from six freely moving rats as they were trained to perform a tone-initiated place-preference task on an open-field platform. To investigate whether place activity was bound to the room- or platform-based coordinate frame (or both), the platform was translated within the room at an “early” and at a “late” phase of task acquisition (Shift 1 and Shift 2). At both time points, CA1 and CA3 place cells demonstrated room-associated and/or platform-associated activity, or remapped in response to the platform shift. Shift 1 revealed place activity that reflected an interaction between a dominant platform-based (proximal) coordinate frame and a weaker room-based (distal) frame because many CA1 and CA3 place fields shifted to a location intermediate to the two reference frames. Shift 2 resulted in place activity that became more strongly bound to either the platform- or room-based coordinate frame, suggesting the emergence of two independent spatial frames of reference (with many more cells participating in platform-based than in room-based representations).

scholarly journals Activities of visual cortical and hippocampal neurons co-fluctuate in freely moving rats during spatial behavior

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Daniel Christopher Haggerty ◽  
Daoyun Ji
Keyword(s):  
Cortical Neurons ◽  
Specific Activity ◽  
Cell Activity ◽  
Place Cell ◽  
Place Cells ◽  
Spatial Behavior ◽  
Freely Moving Rats ◽  
Freely Moving ◽  
Visual Cortical ◽  
Hippocampal Place Cell

Visual cues exert a powerful control over hippocampal place cell activities that encode external spaces. The functional interaction of visual cortical neurons and hippocampal place cells during spatial navigation behavior has yet to be elucidated. Here we show that, like hippocampal place cells, many neurons in the primary visual cortex (V1) of freely moving rats selectively fire at specific locations as animals run repeatedly on a track. The V1 location-specific activity leads hippocampal place cell activity both spatially and temporally. The precise activities of individual V1 neurons fluctuate every time the animal travels through the track, in a correlated fashion with those of hippocampal place cells firing at overlapping locations. The results suggest the existence of visual cortical neurons that are functionally coupled with hippocampal place cells for spatial processing during natural behavior. These visual neurons may also participate in the formation and storage of hippocampal-dependent memories.

scholarly journals Manipulating Hippocampal Place Cell Activity by Single-Cell Stimulation in Freely Moving Mice

Cell Reports ◽  
2018 ◽  
Vol 23 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Maria Diamantaki ◽  
Stefano Coletta ◽  
Khaled Nasr ◽  
Roxana Zeraati ◽  
Sophie Laturnus ◽  
...  
Keyword(s):  
Single Cell ◽  
Cell Activity ◽  
Place Cell ◽  
Cell Stimulation ◽  
Freely Moving ◽  
Hippocampal Place Cell

scholarly journals Dissociation of exteroceptive and idiothetic orientation cues⋮ effect on hippocampal place cells and place navigation

1997 ◽  
Vol 352 (1360) ◽  
pp. 1515-1524 ◽  
Author(s):  
J. Bures ◽  
A. A. Fenton ◽  
Yu. Kaminsky ◽  
J. Rossier ◽  
B. Sacchetti ◽  
...  
Keyword(s):  
Spatial Cognition ◽  
Reference Frames ◽  
Target Location ◽  
Place Cells ◽  
Related Information ◽  
Place Navigation ◽  
Preference Task ◽  
Spatial Memories ◽  
Place Avoidance ◽  
Orientation Cues

Navigation by means of cognitive maps appears to require the hippocampus; hippocampal place cells (PCs) appear to store spatial memories because their discharge is confined to cell–specific places called firing fields (FFs). Experiments with rats manipulated idiothetic and landmark–related information to understand the relationship between PC activity and spatial cognition. Rotating a circular arena in the light caused a discrepancy between these cues. This discrepancy caused most FFs to disappear in both the arena and room reference frames. However, FFs persisted in the rotating arena frame when the discrepancy was reduced by darkness or by a card in the arena. The discrepancy was increased by ’field clamping’the rat in a room–defined FF location by rotations that countered its locomotion. Most FFs dissipated and reappeared an hour or more after the clamp. Place–avoidance experiments showed that navigation uses independent idiothetic and exteroceptive memories. Rats learned to avoid the unmarked footshock region within a circular arena. When acquired on the stable arena in the light, the location of the punishment was learned by using both room and idiothetic cues; extinction in the dark transferred to the following session in the light. If, however, extinction occurred during rotation, only the arena–frame avoidance was extinguished in darkness; the room–defined location was avoided when the lights were turned back on. Idiothetic memory of room–defined avoidance was not formed during rotation in light; regardless of rotation, there was no avoidance when the lights were turned off, but room–frame avoidance reappeared when the lights were turned back on. The place–preference task rewarded visits to an allocentric target location with a randomly dispersed pellet. The resulting behaviour alternated between random pellet searching and target–directed navigation, making it possible to examine PC correlates of these two classes of spatial behaviour. The independence of idiothetic and exteroceptive spatial memories and the disruption of PC firing during rotation suggest that PCs may not be necessary for spatial cognition; this idea can be tested by recordings during the place–avoidance and preference tasks.

scholarly journals Contribution of hippocampal place cell activity to learning and formation of goal-directed navigation in rats

Neuroscience ◽  
2003 ◽  
Vol 117 (4) ◽  
pp. 1025-1035 ◽  
Author(s):  
T Kobayashi ◽  
A.H Tran ◽  
H Nishijo ◽  
T Ono ◽  
G Matsumoto
Keyword(s):  
Cell Activity ◽  
Place Cell ◽  
Hippocampal Place Cell

scholarly journals Hippocampal place cells use vector computations to navigate

2021 ◽  
Author(s):  
Jake Ormond ◽  
John O'Keefe
Keyword(s):  
Spatial Representation ◽  
Vector Fields ◽  
Cell Activity ◽  
Choice Point ◽  
Place Cell ◽  
Place Cells ◽  
Population Vector ◽  
Goal Location ◽  
Optimal Paths ◽  
Independent Assessment

One function of the Hippocampal Cognitive Map is to provide information about salient locations in familiar environments such as those containing reward or danger, and to support navigation towards or away from those locations. Although much is known about how the hippocampus encodes location in world-centred coordinates, how it supports flexible navigation is less well understood. We recorded from CA1 place cells while rats navigated to a goal or freely foraged on the honeycomb maze. The maze tests the animal's ability to navigate using indirect as well as direct paths to the goal and allows the directionality of place cells to be assessed at each choice point during traversal to the goal. Place fields showed strong directional polarization in the navigation task, and to a lesser extent during random foraging. This polarization was characterized by vector fields which converged to sinks distributed throughout the environment. The distribution of these convergence sinks was centred near the goal location, and the population vector field converged on the goal, providing a strong navigational signal. Changing the goal location led to the movement of ConSinks and vector fields towards the new goal and within-days, the ConSink distance to the goal decreased with continued training. The honeycomb maze allows the independent assessment of spatial representation and spatial action in place cell activity and shows how the latter depends on the former. The results suggest a vector-based model of how the hippocampus supports flexible navigation, allowing animals to select optimal paths to destinations from any location in the environment.

scholarly journals Efficient neural decoding of self-location with a deep recurrent network

2018 ◽  
Author(s):  
Ardi Tampuu ◽  
Tambet Matiisen ◽  
H. Freyja Ólafsdóttir ◽  
Caswell Barry ◽  
Raul Vicente
Keyword(s):  
Hippocampal Neurons ◽  
Cell Activity ◽  
Recurrent Network ◽  
Brain Network ◽  
Place Cells ◽  
Neuronal Firing ◽  
Temporal Context ◽  
Central Component ◽  
Neural Decoding ◽  
Freely Moving

AbstractPlace cells in the mammalian hippocampus signal self-location with sparse spatially stable firing fields. Based on observation of place cell activity it is possible to accurately decode an animal’s location. The precision of this decoding sets a lower bound for the amount of information that the hippocampal population conveys about the location of the animal. In this work we use a novel recurrent neural network (RNN) decoder to infer the location of freely moving rats from single unit hippocampal recordings. RNNs are biologically plausible models of neural circuits that learn to incorporate relevant temporal context without the need to make complicated assumptions about the use of prior information to predict the current state. When decoding animal position from spike counts in 1D and 2D-environments, we show that the RNN consistently outperforms a standard Bayesian model with flat priors. In addition, we also conducted a set of sensitivity analysis on the RNN decoder to determine which neurons and sections of firing fields were the most influential. We found that the application of RNNs to neural data allowed flexible integration of temporal context, yielding improved accuracy relative to a commonly used Bayesian approach and opens new avenues for exploration of the neural code.Author summaryBeing able to accurately self-localize is critical for most motile organisms. In mammals, place cells in the hippocampus appear to be a central component of the brain network responsible for this ability. In this work we recorded the activity of a population of hippocampal neurons from freely moving rodents and carried out neural decoding to determine the animals’ locations. We found that a machine learning approach using recurrent neural networks (RNNs) allowed us to predict the rodents’ true positions more accurately than a standard Bayesian method with flat priors. The RNNs are able to take into account past neural activity without making assumptions about the statistics of neuronal firing. Further, by analyzing the representations learned by the network we were able to determine which neurons, and which aspects of their activity, contributed most strongly to the accurate decoding.

General Relativity and Cosmology

2020 ◽  
pp. 227-360
Author(s):  
P. J. E. Peebles
Keyword(s):  
Constant Velocity ◽  
Large Scale ◽  
Reference Frames ◽  
Physical Sciences ◽  
Inertial Frames ◽  
Moving Body ◽  
History Of ◽  
The Subject ◽  
Freely Moving ◽  
The Universe

This chapter discusses the development of physical sciences in seemingly chaotic ways, by paths that are at best dimly seen at the time. It refers to the history of ideas as an important part of any science, and particularly worth examining in cosmology, where the subject has evolved over several generations. It also examines the puzzle of inertia, which traces the connection to Albert Einstein's bold idea that the universe is homogeneous in the large-scale average called “cosmological principle.” The chapter cites Newtonian mechanics that defines a set of preferred motions in space, the inertial reference frames, by the condition that a freely moving body has a constant velocity. It talks about Ernst Mach, who argued that inertial frames are determined relative to the motion of the rest of the matter in the universe.

scholarly journals Lateral entorhinal cortex lesions impair both egocentric and allocentric object–place associations

2020 ◽  
Vol 4 ◽  
pp. 239821282093946
Author(s):  
Maneesh V. Kuruvilla ◽  
David I. G. Wilson ◽  
James A. Ainge
Keyword(s):  
Entorhinal Cortex ◽  
Reference Frames ◽  
Spatial Information ◽  
Unit Recording ◽  
Egocentric Reference Frame ◽  
Spatial Frames Of Reference ◽  
Significant Difference ◽  
Cue Processing ◽  
The Impact

During navigation, landmark processing is critical either for generating an allocentric-based cognitive map or in facilitating egocentric-based strategies. Increasing evidence from manipulation and single-unit recording studies has highlighted the role of the entorhinal cortex in processing landmarks. In particular, the lateral (LEC) and medial (MEC) sub-regions of the entorhinal cortex have been shown to attend to proximal and distal landmarks, respectively. Recent studies have identified a further dissociation in cue processing between the LEC and MEC based on spatial frames of reference. Neurons in the LEC preferentially encode egocentric cues while those in the MEC encode allocentric cues. In this study, we assessed the impact of disrupting the LEC on landmark-based spatial memory in both egocentric and allocentric reference frames. Animals that received excitotoxic lesions of the LEC were significantly impaired, relative to controls, on both egocentric and allocentric versions of an object–place association task. Notably, LEC lesioned animals performed at chance on the egocentric version but above chance on the allocentric version. There was no significant difference in performance between the two groups on an object recognition and spatial T-maze task. Taken together, these results indicate that the LEC plays a role in feature integration more broadly and in specifically processing spatial information within an egocentric reference frame.

The role of visual experience in spatial reference frame preference

2012 ◽  
Vol 25 (0) ◽  
pp. 18
Author(s):  
Achille Pasqualotto
Keyword(s):  
Reference Frame ◽  
Spatial Representation ◽  
Visual Experience ◽  
Reference Frames ◽  
Single Point ◽  
Memory Test ◽  
Object Locations ◽  
Congenitally Blind ◽  
Spatial Reference Frame

How do people remember the location of objects? Location is always relative, and thus depends on a reference frame. There are two types of reference frames: egocentric (or observer-based) and allocentric (or environmental-based). Here we investigated the reference frame people used to remember object locations in a large room. We also examined whether the choice of a given reference frame is dictated by visual experience. Thus we tested congenitally blind, late blind, and sighted blindfolded participants. Objects were organized in a structured configuration and then explored one-by-one with participants walking back and forth from a single point. After the exploration of the locations, a spatial memory test was conducted. The memory test required participants to imagine being inside the array of objects, being oriented along a given heading, and then pointing towards the required object. Crucially the headings were either aligned to the allocentric structure of the configuration, that is rows and columns, or aligned to the egocentric route walked during the exploration of the objects. The spatial representation used by the participants can be revealed by better performance when the imagined heading in the test matches the spatial representation used. We found that participants with visual experience, that is late blind and blindfolded sighted, were better with headings aligned to the allocentric structure of the configuration. On the contrary, congenitally blind were more accurate with headings aligned to the egocentric walked routes. This suggests that visual experience during early development determines a preference for an allocentric frame of reference.

Inhibition of Leydig cell activity in vivo and in vitro in hypothyroid rats

1995 ◽  
Vol 144 (2) ◽  
pp. 293-300 ◽  
Author(s):  
F F Antony ◽  
M M Aruldhas ◽  
R C R Udhayakumar ◽  
R R M Maran ◽  
P Govindarajulu
Keyword(s):  
Body Weight ◽  
Leydig Cell ◽  
Specific Activity ◽  
Cell Activity ◽  
Adult Rats ◽  
Hydroxysteroid Dehydrogenases ◽  
Serum Lh ◽  
Prepubertal Age

Abstract Leydig cell steroidogenic activity under basal and stimulated conditions was studied in hypothyroid rats. Hypothyroidism was induced at a prepubertal age (30 days postpartum) by surgical thyroidectomy, and l-thyroxine (T4) supplementation (6 μg/100 g body weight/day for 30 days) to hypothyroid rats was begun after 30 days. Hypothyroidism for 60 days reduced serum LH and FSH without affecting prolactin. Serum and intratesticular testosterone and the specific activity of Leydig cell 3β- and 17β-hydroxysteroid dehydrogenases diminished in hypothyroid rats. The stimulatory effect of LH on Leydig cell steroidogenic activity and cAMP was also adversely affected in hypothyroid rats. All these changes were reversed by T4 supplementation. The present results suggest that prepubertal hypothyroidism suppresses both basal and stimulated Leydig cell activity in adult rats. Journal of Endocrinology (1995) 144, 293–300

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