Investigating Dopaminergic, Serotoninergic and Oxytocinergic Signaling in the Nucleus Accumbens Medial Shell and its Role in Mice Maternal Motivation

Number of pages70
Master program titleMaîtrise universitaire interdisciplinaire en neurosciences
Defense date2024-05-03

Introduction: This master’s thesis investigated maternal motivation in female mice, with a particular focus on the neurobiological mechanisms underpinning pup retrieval behavior, which is of primary importance for the offspring’s survival.

Method: Using a mouse model, we focused on the role of the Nucleus Accumbens (NAc) in pup retrieval behavior, and how dopaminergic (DA), serotoninergic (5HT), and oxytocinergic (OXT) neurons projecting to its medial shell part could be involved in this caregiving behavior. This research also addressed the impacts of the maternal status (i.e., dam vs. nulliparous female) and anxiety level (i.e., high vs. low anxiogenic environment) on pup retrieval. We used a combination of different techniques including pup retrieval behavioral tests, anatomical tracing, immunohistochemical techniques, fiber photometry recordings and chemogenetic manipulations to address these questions.

Results: Our results highlighted that pup retrieval is spontaneously performed by dams, whereas nulliparous females learn to express it when exposed to dams and pups. Additionally, the anxiety level impacts pup retrieval performance, with females performing pup retrieval less in the anxiogenic EPM as compared to the familiar arena. Our results also suggest the critical role of the NAc medial shell, activated in females engaged in pup retrieval. We found that this specific NAc subregion receives direct inputs from DA, 5HT, and OXT neurons, mainly co-localized in the more caudal NAc medial shell. Finally, fiber photometry recordings revealed distinct DA, 5HT and OXT release patterns within the NAc medial shell during pup retrieval, which were modulated by the environment in which pup retrieval was performed and mice status.

Conclusions: Increasing our understanding of the neurobiological basis of maternal motivation, these findings call for further research focusing on the brain mechanisms underpinning maternal motivation, how they are influenced by external stressors, mice status and reflected by neuromodulator interactions in the NAc medial shell.

Citation (ISO format)
ZOCCA, Marie Charlotte Kazimiera. Investigating Dopaminergic, Serotoninergic and Oxytocinergic Signaling in the Nucleus Accumbens Medial Shell and its Role in Mice Maternal Motivation. 2024.
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Master thesis
  • PID : unige:177350

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First validation05/27/2024 3:08:51 PM
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