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

Haggerty DC, Ji D - Elife (2015)

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, United States.

ABSTRACT
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.

No MeSH data available.


Bi-directional firing of V1 and CA1 cells on the C-shaped track.(A) Firing activity of a V1 cell (lap-by-lap spike raster and average firing rate curve; see Figure 2 legend for details) on two trajectories with opposite running directions (left) and the cross-correlogram of the cell's two firing rate curves (right). Vertical Gray lines: land mark positions (corners) of the track. Arrows: running directions. Note that the peaks appeared before the animal passed the same landmarks (∆, prospective firing) on both running directions, resulted in a primary peak (*) at a positive position lag in the cross-correlogram. (B) Same as A, but for an example of CA1 cell showing consistent firing after a landmark (o, retrospective firing) on both directions. (C, D) Histograms of the cross-correlogram peak positions of all V1 (C) and CA1 (D) cells with significant bi-directional firing. Black lines: smoothed curves of the histograms. Note that both the V1 and CA1 distributions appeared to be bi-modal, suggesting prospective or retrospective firing for V1 and CA1 bi-directional cells.DOI:http://dx.doi.org/10.7554/eLife.08902.006
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4595967&req=5

fig4: Bi-directional firing of V1 and CA1 cells on the C-shaped track.(A) Firing activity of a V1 cell (lap-by-lap spike raster and average firing rate curve; see Figure 2 legend for details) on two trajectories with opposite running directions (left) and the cross-correlogram of the cell's two firing rate curves (right). Vertical Gray lines: land mark positions (corners) of the track. Arrows: running directions. Note that the peaks appeared before the animal passed the same landmarks (∆, prospective firing) on both running directions, resulted in a primary peak (*) at a positive position lag in the cross-correlogram. (B) Same as A, but for an example of CA1 cell showing consistent firing after a landmark (o, retrospective firing) on both directions. (C, D) Histograms of the cross-correlogram peak positions of all V1 (C) and CA1 (D) cells with significant bi-directional firing. Black lines: smoothed curves of the histograms. Note that both the V1 and CA1 distributions appeared to be bi-modal, suggesting prospective or retrospective firing for V1 and CA1 bi-directional cells.DOI:http://dx.doi.org/10.7554/eLife.08902.006

Mentions: The bias of V1 and CA1 fields around the landmarks on both directions prompted us to examine the directionality of V1 and CA1 firing fields. We observed that some V1 cells fired in front of or behind the landmarks on two opposite running directions, which we termed ‘prospective’ or ‘retrospective’ firing as in a previous study (Battaglia et al., 2004). An example of V1 cell with prospective firing is shown in Figure 4A, which was quantified by a significant peak at a positive position lag (36 cm, p < 0.0001, Pearson's r) in the cross-correlogram between the cell's firing rate curves on the two trajectories. An example of CA1 cell with retrospective firing is shown in Figure 4B, with a significant peak at a negative position lag (−18 cm, p < 0.0001) in the cross-correlogram between its firing rate curves on the two trajectories. We found that among all trajectory-active cells, 9.7% of V1 cells (N = 75) and 10.4% of CA1 cells (N = 212) were bidirectional, defined as those with a significant peak within [−50, 50] cm in their rate curve cross-correlograms (see ‘Materials and methods’). The cross-correlogram peak positions of these bidirectional V1 cells display a bimodal distribution with two groups around 26 cm and −26 cm (Figure 4C), which corresponded to prospective and retrospective firing, respectively. Similarly, the peak positions of CA1 cells also show a bimodal distribution with two groups around 18 cm and −28 cm (Figure 4D). This result suggests that a group of V1 cells responded to the same landmarks on both directions by either ‘looking’ ahead or back to the landmarks.10.7554/eLife.08902.006Figure 4.Bi-directional firing of V1 and CA1 cells on the C-shaped track.


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

Haggerty DC, Ji D - Elife (2015)

Bi-directional firing of V1 and CA1 cells on the C-shaped track.(A) Firing activity of a V1 cell (lap-by-lap spike raster and average firing rate curve; see Figure 2 legend for details) on two trajectories with opposite running directions (left) and the cross-correlogram of the cell's two firing rate curves (right). Vertical Gray lines: land mark positions (corners) of the track. Arrows: running directions. Note that the peaks appeared before the animal passed the same landmarks (∆, prospective firing) on both running directions, resulted in a primary peak (*) at a positive position lag in the cross-correlogram. (B) Same as A, but for an example of CA1 cell showing consistent firing after a landmark (o, retrospective firing) on both directions. (C, D) Histograms of the cross-correlogram peak positions of all V1 (C) and CA1 (D) cells with significant bi-directional firing. Black lines: smoothed curves of the histograms. Note that both the V1 and CA1 distributions appeared to be bi-modal, suggesting prospective or retrospective firing for V1 and CA1 bi-directional cells.DOI:http://dx.doi.org/10.7554/eLife.08902.006
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4595967&req=5

fig4: Bi-directional firing of V1 and CA1 cells on the C-shaped track.(A) Firing activity of a V1 cell (lap-by-lap spike raster and average firing rate curve; see Figure 2 legend for details) on two trajectories with opposite running directions (left) and the cross-correlogram of the cell's two firing rate curves (right). Vertical Gray lines: land mark positions (corners) of the track. Arrows: running directions. Note that the peaks appeared before the animal passed the same landmarks (∆, prospective firing) on both running directions, resulted in a primary peak (*) at a positive position lag in the cross-correlogram. (B) Same as A, but for an example of CA1 cell showing consistent firing after a landmark (o, retrospective firing) on both directions. (C, D) Histograms of the cross-correlogram peak positions of all V1 (C) and CA1 (D) cells with significant bi-directional firing. Black lines: smoothed curves of the histograms. Note that both the V1 and CA1 distributions appeared to be bi-modal, suggesting prospective or retrospective firing for V1 and CA1 bi-directional cells.DOI:http://dx.doi.org/10.7554/eLife.08902.006
Mentions: The bias of V1 and CA1 fields around the landmarks on both directions prompted us to examine the directionality of V1 and CA1 firing fields. We observed that some V1 cells fired in front of or behind the landmarks on two opposite running directions, which we termed ‘prospective’ or ‘retrospective’ firing as in a previous study (Battaglia et al., 2004). An example of V1 cell with prospective firing is shown in Figure 4A, which was quantified by a significant peak at a positive position lag (36 cm, p < 0.0001, Pearson's r) in the cross-correlogram between the cell's firing rate curves on the two trajectories. An example of CA1 cell with retrospective firing is shown in Figure 4B, with a significant peak at a negative position lag (−18 cm, p < 0.0001) in the cross-correlogram between its firing rate curves on the two trajectories. We found that among all trajectory-active cells, 9.7% of V1 cells (N = 75) and 10.4% of CA1 cells (N = 212) were bidirectional, defined as those with a significant peak within [−50, 50] cm in their rate curve cross-correlograms (see ‘Materials and methods’). The cross-correlogram peak positions of these bidirectional V1 cells display a bimodal distribution with two groups around 26 cm and −26 cm (Figure 4C), which corresponded to prospective and retrospective firing, respectively. Similarly, the peak positions of CA1 cells also show a bimodal distribution with two groups around 18 cm and −28 cm (Figure 4D). This result suggests that a group of V1 cells responded to the same landmarks on both directions by either ‘looking’ ahead or back to the landmarks.10.7554/eLife.08902.006Figure 4.Bi-directional firing of V1 and CA1 cells on the C-shaped track.

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, United States.

ABSTRACT
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.

No MeSH data available.