Sun, 27 Jul 2008 07:23:13 BST CiteULike: nelmor's place-cell http://www.citeulike.org/user/nelmor/tag/place-cell CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/nelmor/article/2961490 <i>Science, Vol. 321, No. 5885. (4 July 2008), pp. 140-143.</i><br /><br />To determine how spatial scale is represented in the pyramidal cell population of the hippocampus, we recorded neural activity at multiple longitudinal levels of this brain area while rats ran back and forth on an 18-meter-long linear track. CA3 cells had well-defined place fields at all levels. The scale of representation increased almost linearly from <1 meter at the dorsal pole to [~]10 meters at the ventral pole. The results suggest that the place-cell map includes the entire hippocampus and that environments are represented in the hippocampus at a topographically graded but finite continuum of scales. 10.1126/science.1157086 Finite Scale of Spatial Representation in the Hippocampus Kirsten Kjelstrup Trygve Solstad Vegard Brun Torkel Hafting Stefan Leutgeb Menno Witter Edvard Moser May-Britt Moser doi:10.1126/science.1157086 Science, Vol. 321, No. 5885. (4 July 2008), pp. 140-143. 2008-07-03T23:30:05-00:00 2008 Science 321 5885 140 143 hippocampus place-cell http://www.citeulike.org/user/nelmor/article/2901921 <i>Neuron, Vol. 37, No. 3. (6 February 2003), pp. 485-497.</i><br /><br />We recorded neurons from the hippocampus of freely behaving rats during an auditory fear conditioning task. Rats received either paired or unpaired presentations of an auditory conditioned stimulus (CS) and an electric shock unconditioned stimulus (US). Hippocampal neurons (place and theta cells) acquired responses to the auditory CS in the paired but not in the unpaired group. After CS-US pairing, rhythmic firing of theta cells became synchronized to the onset of the CS. Conditioned responses of place cells were gated by their location-specific firing, so that after CS-US pairing, place cells responded to the CS only when the rat was within the cell's place field. These findings may help to elucidate how the hippocampus contributes to context-specific memory formation during associative learning. Hippocampal place cells acquire location-specific responses to the conditioned stimulus during auditory fear conditioning. MA Moita S Rosis Y Zhou JE LeDoux HT Blair Neuron, Vol. 37, No. 3. (6 February 2003), pp. 485-497. 2008-06-17T10:01:25-00:00 2003 Neuron 0896-6273 37 3 485 497 auditory fear-conditioning hippocampus place-cell rats http://www.citeulike.org/user/nelmor/article/2861907 <i>J. Neurosci., Vol. 28, No. 23. (4 June 2008), pp. 5959-5964.</i><br /><br />In rodent hippocampus, neuronal activity is organized by a 6-10 Hz theta oscillation. The spike timing of hippocampal pyramidal cells with respect to the theta rhythm correlates with an animal's position in space. This correlation has been suggested to indicate an explicit temporal code for position. Alternatively, it may be interpreted as a byproduct of theta-dependent dynamics of spatial information flow in hippocampus. Here we show that place cell activity on different phases of theta reflects positions shifted into the future or past along the animal's trajectory in a two-dimensional environment. The phases encoding future and past positions are consistent across recorded CA1 place cells, indicating a coherent representation at the network level. Consistent theta-dependent time offsets are not simply a consequence of phase-position correlation (phase precession), because they are no longer seen after data randomization that preserves the phase-position relationship. The scale of these time offsets, 100-300 ms, is similar to the latencies of hippocampal activity after sensory input and before motor output, suggesting that offset activity may maintain coherent brain activity in the face of information processing delays. 10.1523/JNEUROSCI.5262-07.2008 Theta-Mediated Dynamics of Spatial Information in Hippocampus Vladimir Itskov Eva Pastalkova Kenji Mizuseki Gyorgy Buzsaki Kenneth Harris doi:10.1523/JNEUROSCI.5262-07.2008 J. Neurosci., Vol. 28, No. 23. (4 June 2008), pp. 5959-5964. 2008-06-04T17:20:45-00:00 2008 J. Neurosci. 28 23 5959 5964 hippocampus phase-precession place-cell theta http://www.citeulike.org/user/nelmor/article/2744777 <i>J. Neurosci., Vol. 28, No. 18. (30 April 2008), pp. 4679-4689.</i><br /><br />The hippocampus is essential for spatial navigation, which may involve sequential learning. However, how the hippocampus encodes new sequences in familiar environments is unknown. To study the impact of novel spatial sequences on the activity of hippocampal neurons, we monitored hippocampal ensembles while rats learned to switch from two familiar trajectories to a new one in a familiar environment. Here, we show that this novel spatial experience induces two types of changes in firing rates, but not locations of hippocampal place cells. First, place-cell firing rates on the two familiar trajectories start to change before the actual behavioral switch to the new trajectory. Second, repeated exposure on the new trajectory is associated with an increased dependence of place-cell firing rates on immediate past locations. The result suggests that sequence encoding in the hippocampus may involve integration of information about the recent past into current state. 10.1523/JNEUROSCI.4597-07.2008 Firing Rate Dynamics in the Hippocampus Induced by Trajectory Learning Daoyun Ji Matthew Wilson doi:10.1523/JNEUROSCI.4597-07.2008 J. Neurosci., Vol. 28, No. 18. (30 April 2008), pp. 4679-4689. 2008-05-02T09:18:17-00:00 2008 J. Neurosci. 28 18 4679 4689 hippocampus navigation place-cell rate-remapping http://www.citeulike.org/user/nelmor/article/2718509 <i>Nat Neurosci, Vol. 11, No. 5. (May 2008), pp. 587-594.</i> Theta phase-specific codes for two-dimensional position, trajectory and heading in the hippocampus John Huxter Timothy Senior Kevin Allen Jozsef Csicsvari doi:10.1038/nn.2106 Nat Neurosci, Vol. 11, No. 5. (May 2008), pp. 587-594. 2008-04-25T13:57:55-00:00 2008 Nat Neurosci 11 5 587 594 Nature Publishing Group hippocampus phase-precession place-cell theta http://www.citeulike.org/user/nelmor/article/2616025 <i>J Neurosci, Vol. 22, No. 20. (15 October 2002), pp. 9035-9047.</i><br /><br />This study examined the performance of spatial problems by rats when purely behavioral manipulations disturb the relationship between the place cell representation and the cues used to solve the problems. Place cells were recorded while rats performed a task in which they had to locate a goal in a gray cylinder. In the "far" task, the unmarked goal was displaced by a large fixed distance from a white card on the cylinder wall. In the "near" task, the unmarked goal was directly in front of the card. Finally, in the "cue" task the goal was marked by a black disk on the cylinder floor. Relationships between visible stimuli and place cell activity were manipulated by conducting either "hidden" (with the rat in its home cage) or "visible" (with the rat in the recording apparatus) rotations of the wall card and, when present, independent rotations of the black disk. Hidden card rotations generally caused equal firing field rotations, whereas visible card rotations often did not cause fields to move. In the far task, visible card rotations were associated with a strong decrease of correct responses in the card-referred goal area. Most rats tended to search the goal in the field-referred area. In the near task, visible card rotations were associated with a moderate decrease of performance, with rats searching the goal at the wall card. Finally, field placements had no effect on performance in the cue task. Thus, visible rotations tended to disrupt the relationship between firing fields and cues in all tasks but impaired performance only in the task that required map-based navigation. These results provide strong new evidence in favor of the spatial mapping theory of hippocampal function. Relationships between place cell firing fields and navigational decisions by rats. PP Lenck-Santini RU Muller E Save B Poucet J Neurosci, Vol. 22, No. 20. (15 October 2002), pp. 9035-9047. 2008-03-31T12:22:57-00:00 2002 J Neurosci 1529-2401 22 20 9035 9047 hippocampus map navigation place-cell rats http://www.citeulike.org/user/nelmor/article/2282625 <i>Neuron, Vol. 57, No. 2. (24 January 2008), pp. 290-302.</i><br /><br />Summary Place-specific firing in the hippocampus is determined by path integration-based spatial representations in the grid-cell network of the medial entorhinal cortex. Output from this network is conveyed directly to CA1 of the hippocampus by projections from principal neurons in layer III, but also indirectly by axons from layer II to the dentate gyrus and CA3. The direct pathway is sufficient for spatial firing in CA1, but it is not known whether similar firing can also be supported by the input from CA3. To test this possibility, we made selective lesions in layer III of medial entorhinal cortex by local infusion of the neurotoxin [gamma]-acetylenic GABA. Firing fields in CA1 became larger and more dispersed after cell loss in layer III, whereas CA3 cells, which receive layer II input, still had sharp firing fields. Thus, the direct projection is necessary for precise spatial firing in the CA1 place cell population. Impaired Spatial Representation in CA1 after Lesion of Direct Input from Entorhinal Cortex Vegard Brun Stefan Leutgeb Hui-Qiu Wu Robert Schwarcz Menno Witter Edvard Moser May-Britt Moser doi:10.1016/j.neuron.2007.11.034 Neuron, Vol. 57, No. 2. (24 January 2008), pp. 290-302. 2008-01-24T01:04:55-00:00 2008 Neuron 57 2 290 302 ca1 ca3 erc learning lesion place-cell http://www.citeulike.org/user/nelmor/article/1884805 <i>J. Neurosci., Vol. 27, No. 45. (7 November 2007), pp. 12176-12189.</i><br /><br />Neural ensembles were recorded from the CA3 region of rats running on T-based decision tasks. Examination of neural representations of space at fast time scales revealed a transient but repeatable phenomenon as rats made a decision: the location reconstructed from the neural ensemble swept forward, first down one path and then the other. Estimated representations were coherent and preferentially swept ahead of the animal rather than behind the animal, implying it represented future possibilities rather than recently traveled paths. Similar phenomena occurred at other important decisions (such as in recovery from an error). Local field potentials from these sites contained pronounced theta and gamma frequencies, but no sharp wave frequencies. Forward-shifted spatial representations were influenced by task demands and experience. These data suggest that the hippocampus does not represent space as a passive computation, but rather that hippocampal spatial processing is an active process likely regulated by cognitive mechanisms. 10.1523/JNEUROSCI.3761-07.2007 Neural Ensembles in CA3 Transiently Encode Paths Forward of the Animal at a Decision Point Adam Johnson David Redish doi:10.1523/JNEUROSCI.3761-07.2007 J. Neurosci., Vol. 27, No. 45. (7 November 2007), pp. 12176-12189. 2007-11-08T13:38:39-00:00 2007 J. Neurosci. 27 45 12176 12189 analysis ca3 decision hippocampus place-cell http://www.citeulike.org/user/nelmor/article/933319 <i>Trends Neurosci (25 October 2006)</i><br /><br />It has recently been recognized that the entorhinal cortex has a crucial role in spatial representation and navigation. How the position of an animal is computed within the entorhinal circuitry remains to be determined, but the architectural organization of this brain area might provide some clues. Here, we review three organizational principles - recurrent connectivity, interlaminar connectivity and modular organization - and propose how each of them might contribute to the emergence and maintenance of positional representations in entorhinal neural networks. Spatial representation and the architecture of the entorhinal cortex. Menno P Witter Edvard I Moser doi:10.1016/j.tins.2006.10.003 Trends Neurosci (25 October 2006) 2006-11-06T12:14:14-00:00 2006 Trends Neurosci 0166-2236 erc place place-cell review http://www.citeulike.org/user/nelmor/article/834568 <i>Brain Res, Vol. 34, No. 1. (November 1971), pp. 171-175.</i> The hippocampus as a spatial map. Preliminary evidence from unit activity in the freely-moving rat. J O'Keefe J Dostrovsky Brain Res, Vol. 34, No. 1. (November 1971), pp. 171-175. 2006-09-08T04:23:17-00:00 1971 Brain Res 0006-8993 34 1 171 175 hippocampus place-cell http://www.citeulike.org/user/nelmor/article/833099 <i>Neuron, Vol. 51, No. 5. (7 September 2006), pp. 639-650.</i><br /><br />SummaryIn a continuous T-maze alternation task, CA1 complex-spike neurons in the hippocampus differentially fire as the rat traverses overlapping segments of the maze (i.e., the stem) repeatedly via alternate routes. The temporal dynamics of this phenomenon were further investigated in the current study. Rats learned the alternation task from the first day of acquisition and the differential firing pattern in the stem was observed accordingly. More importantly, we report a phenomenon in which spatial correlates of CA1 neuronal ensembles gradually changed from their original firing locations, shifting toward prospective goal locations in the continuous T-maze alternation task. The relative locations of simultaneously recorded firing fields, however, were preserved within the ensemble spatial representation during this shifting. The within-session shifts in[no-break space]preferred firing locations in the absence of any changes in the environment suggest that certain cognitive factors can significantly alter the location-bound coding scheme of hippocampal neurons. Gradual Translocation of Spatial Correlates of Neuronal Firing in the Hippocampus toward Prospective Reward Locations Inah Lee Amy Griffin Eric Zilli Howard Eichenbaum Michael Hasselmo doi:10.1016/j.neuron.2006.06.033 Neuron, Vol. 51, No. 5. (7 September 2006), pp. 639-650. 2006-09-07T00:50:56-00:00 2006 Neuron 51 5 639 650 hippocampus methods place-cell reward http://www.citeulike.org/user/nelmor/article/72859 <i>Nature Neuroscience, Vol. 8, No. 1. (12 December 2004), 67.</i> Spike phase precession persists after transient intrahippocampal perturbation Michaël Zugaro Lénaïc Monconduit György Buzsáki doi:10.1038/nn1369 Nature Neuroscience, Vol. 8, No. 1. (12 December 2004), 67. 2005-01-07T01:56:50-00:00 2004 Nature Neuroscience 1097-6256 8 1 67 Nature Publishing Group hippocampus phase-precession place-cell