Dynamics of Place, Boundary and Object Encoding In Rat Anterior Claustrum – our latest paper available for download

We have a new paper which explores the functions of the claustrum – an anatomically substantial but largely unexplored and uninvestigated structure. Francis Crick, in his final paper, famously suggested that the claustrum had a ‘possible relationship to the processes that give rise to integrated conscious percepts’ (i.e. that it was responsible in some way for orchestrating the activity that gives rise to consciousness in the brain).

We have quite a different take on the functions of the claustrum – we suggest that instead it has a previously unrecognised role in the representation of 3d space in the brain, and in the conjoint encoding of object and spatial information.

The abstract:

Discrete populations of brain cells signal differing types of spatial information. These ‘spatial cells’ are largely confined to a closely-connected network of sites. We describe here, for the first time, cells in the anterior claustrum of the freely-moving rat encoding place, boundary and object information. This novel claustral spatial signal potentially directly modulates a wide variety of anterior cortical regions. We hypothesise that one of the functions of the claustrum is to provide information about body position, boundaries and landmark information, enabling dynamic control of behaviour.

Figure 1 – Place cells in rat anterior claustrum. (A) Examples of two spatially-tuned claustral cells recorded over consecutive sessions with changes in environmental conditions. Each cell was recorded in the light, darkness, light and after rotation of visual cue in the light. The pattern of response suggests that activity of claustral place cells is anchored to visual cues (the location of main cue – cue card with black and white stripes is marked on the figure by striped rectangle). For each recording session the following are presented in columns: path of the animal recorded during 20-min session with superimposed firing activity of the unit; firing intensity map with a maximum firing frequency; place map; polar plot; spike waveform and autocorrelation ±1000 ms (those parameters are presented in similar layout in C-E). (B) Estimated locations of spatially-tuned cells presented in Figure 1 reconstructed on histological specimen. On the left side of the histological slide, a schematic anatomical figure with borderlines between structures for similar antero-posterior coordinates is presented (C) Claustral place cells form place fields in environments of different geometrical shapes when tested after transitions from a circular to square environments in the light. (D and E) Example of two more place cells recorded in the light. The location of place fields was similar in majority of cells suggesting that their activity may be strongly anchored to the visual and possibly other cues in experimental room. (F) Examples of three place cells with different locations of place fields in the experimental arena. Place fields located in other parts of experimental arena than those formed by cells #1 - #6 were less prevalent (like in cells #7 and #8). Cell #7 exhibited both spatial tuning and directional tuning. For each cell in rows are presented: path of the animal with superimposed firing activity, firing intensity map, place map, polar plot, spike waveform and autocorrelation ± 1000 ms. Abbreviations: aca, anterior commissure, anterior part; cc, corpus callosum; IC, insular cortex; IL, infralimbic cortex; OC, orbital cortex.
Figure 1 – Place cells in rat anterior claustrum. (A) Examples of two spatially-tuned claustral cells recorded over consecutive sessions with changes in environmental conditions. Each cell was recorded in the light, darkness, light and after rotation of visual cue in the light. The pattern of response suggests that activity of claustral place cells is anchored to visual cues (the location of main cue – cue card with black and white stripes is marked on the figure by striped rectangle). For each recording session the following are presented in columns: path of the animal recorded during 20-min session with superimposed firing activity of the unit; firing intensity map with a maximum firing frequency; place map; polar plot; spike waveform and autocorrelation ±1000 ms (those parameters are presented in similar layout in C-E). (B) Estimated locations of spatially-tuned cells presented in Figure 1 reconstructed on histological specimen. On the left side of the histological slide, a schematic anatomical figure with borderlines between structures for similar antero-posterior coordinates is presented (C) Claustral place cells form place fields in environments of different geometrical shapes when tested after transitions from a circular to square environments in the light. (D and E) Example of two more place cells recorded in the light. The location of place fields was similar in majority of cells suggesting that their activity may be strongly anchored to the visual and possibly other cues in experimental room. (F) Examples of three place cells with different locations of place fields in the experimental arena. Place fields located in other parts of experimental arena than those formed by cells #1 – #6 were less prevalent (like in cells #7 and #8). Cell #7 exhibited both spatial tuning and directional tuning. For each cell in rows are presented: path of the animal with superimposed firing activity, firing intensity map, place map, polar plot, spike waveform and autocorrelation ± 1000 ms. Abbreviations: aca, anterior commissure, anterior part; cc, corpus callosum; IC, insular cortex; IL, infralimbic cortex; OC, orbital cortex.

Author: Shane O'Mara

Neuroscientist

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