Differences in reward biased spatial representations in the lateral septum and hippocampus

Area of Science:

• Neuroscience
• Spatial Navigation
• Reward Processing

Background:

• The lateral septum (LS) receives hippocampal input and is implicated in spatial representation.
• The precise nature of place encoding and its integration with reward signals in the LS is not well understood.

Purpose of the Study:

• To investigate the characteristics of place representation in the lateral septum (LS) during a navigation task.
• To determine if spatial information in the LS is combined with reward signaling.

Main Methods:

• Simultaneous electrophysiological recordings from the CA1 region of the hippocampus and the caudodorsal LS in rats.
• Analysis of spatial firing patterns and place fields during a rewarded navigation task.

Main Results:

• LS place cells were less numerous than hippocampal place cells but showed similar field size and number of fields per cell.
• LS place cell fields exhibited a distribution skewed towards reward locations.
• Hippocampal-LS spike cross-correlations were highest for cells with reward-proximate place fields.

Conclusions:

• The lateral septum (LS) encodes spatial information with a bias towards reward locations.
• The LS likely plays a role in transmitting task-relevant spatial information, potentially integrated with reward cues, to downstream brain regions like the VTA.