Combined social and spatial coding in a descending projection from the prefrontal cortex

Abstract

Social interactions are crucial to the survival and well-being of all mammals, including humans. Although the prelimbic cortex (PL, part of medial prefrontal cortex) has been implicated in social behavior, it is not clear which neurons are relevant, nor how they contribute. We found that the PL contains anatomically and molecularly distinct subpopulations of neurons that target 3 downstream regions that have been implicated in social behavior: the nucleus accumbens (NAc), the amygdala, and the ventral tegmental area. Activation of NAc-projecting PL neurons (PL-NAc), but not the other subpopulations, decreased preference for a social target, suggesting an unique contribution of this population to social behavior. To determine what information PL-NAc neurons convey, we recorded selectively from them, and found that individual neurons were active during social investigation, but only in specific spatial locations . Spatially-specific inhibition of these neurons prevented the formation of a social-spatial association at the inhibited location. In contrast, spatially nonspecific inhibition did not affect social behavior. Thus, the unexpected combination of social and spatial information within the PL-NAc population appears to support socially motivated behavior by enabling the formation of social-spatial associations.All rights reserved. No reuse allowed without permission.(which was not peer-reviewed) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.

NINscope: a versatile miniscope for multi-region circuit investigations

“…Thus, imaging approaches can reveal how individual cells embedded in a larger network display coordinated activity during different stages of behavior or training (Wagner et al 2017;Heffley et al 2018;Galiñanes, Bonardi, and Huber 2018;Giovannucci et al 2017) . Moreover, because of their ability to record in freely moving animals, miniscopes have been instrumental in uncovering neural activity patterns occurring during natural behaviors and related brain-states including social interactions (Murugan et al 2017;Remedios et al 2017;Liang et al 2018;Kingsbury et al 2019) or sleep Cox, Pinto, and Dan 2016) with fully intact vestibular input.…”

A Compact Head‐Mounted Endoscope for In Vivo Calcium Imaging in Freely Behaving Mice

“…For example, properties of individual neurons can be identified using calcium transient data. Previous studies have identified position-encoding neurons in the hippocampus and cortex (Murugan et al, 2017;Wagatsuma et al, 2018) and stimulus or expectationencoding neurons in the amygdala (Yu et al, 2017). Analysis at the population level has yielded insights into the representations of social stimuli Yu et al, 2017) and fearful memories in the amygdala (Grewe et al, 2017).…”

“…In other situations, it may be necessary to express GCaMP using viral methods, for example if transgenic mice show poor expression in the target brain region. Further, experiments that seek to image activity from subpopula-tions of neurons that are genetically defined (Kamigaki & Dan, 2017) or defined by projection pattern (Murugan et al, 2017;Zhou et al, 2017) may require the use of Cre-dependent AAVs in combination with the appropriate Cre-expressing mouse lines or viruses. In any experiment relying on AAV-mediated GCaMP expression, experimenters should give adequate time between AAV infusion and imaging to allow expression of the calcium indicator to peak (typically at least 1 month) and, as mentioned above, ensure that the specific methods being used results in stable protein expression over the full duration of the imaging experiment (Resendez et al, 2016).…”

Differential encoding in prefrontal cortex projection neuron classes across cognitive tasks

“…Several studies in the mouse PFC have linked projection-defined excitatory neuron types to diverse aspects of cognitive function. For example, nucleus accumbens-projecting medial PFC (mPFC→NAc) neurons were reported to have different roles in the conjunctive encoding of social and spatial targets (Murugan et al, 2017), the restraint of reward seeking (Kim et al, 2017), and the representation of reward predicting cues (Otis et al, 2017). mPFC→PAG neurons were reported to be a key node that dopamine acts on to modulate the signal-to-noise ratio in encoding of aversive stimuli (Vander Weele et al, 2018).…”