Oxytocin Neurons in the Paraventricular Nucleus Modulate Pup Care and Infanticide Behaviors in Virgin Mandarin Voles

Kernkonzepte

Oxytocin neurons in the paraventricular nucleus and their projections to the medial prefrontal cortex regulate the expression of pup care and infanticide behaviors in virgin mandarin voles.

Zusammenfassung

This study used virgin mandarin voles, a monogamous rodent species, to investigate the neural mechanisms underlying pup care and infanticide behaviors. The key findings are:

More oxytocin (OT) neurons in the paraventricular nucleus (PVN) were activated during pup care compared to infanticide behaviors in both male and female voles.

Optogenetic activation of OT neurons in the PVN facilitated pup care behaviors (approach, retrieval, crouching) in male voles, but had no effect on females. Activation of these neurons inhibited infanticide in both sexes, while inhibition promoted infanticide.

Fiber photometry recordings showed that OT release in the medial prefrontal cortex (mPFC) increased upon approaching and retrieving pups in pup-care voles, but decreased during infanticide in infanticide voles.

Optogenetic activation of the PVN OT neuron projections to the mPFC promoted the onset of pup care in male pup-care voles and inhibited infanticide in both sexes. Inhibition of this projection had the opposite effects.

Peripheral administration of OT promoted pup care behaviors in male voles and suppressed infanticide in both sexes.

These results demonstrate that the OT system, particularly the PVN OT neurons and their projections to the mPFC, play a key role in regulating pup-directed behaviors in virgin mandarin voles. This provides insights into the neural mechanisms underlying the expression of parental care and infanticide.

Statistiken

"More OT neurons in the PVN were activated during pup care (11-14%) than infanticide (3-7%) in both male and female voles."
"Optogenetic activation of PVN OT neurons significantly reduced the latency to approach and retrieve pups, and prolonged crouching time in pup-care male voles."
"Optogenetic activation of PVN OT neurons significantly reduced the latency to approach and attack pups in male and female infanticide voles."
"Optogenetic activation of PVN-mPFC OT projection terminals shortened the latency to approach and retrieve pups, and facilitated the initiation of pup care in male pup-care voles."
"Optogenetic activation of PVN-mPFC OT projection terminals prolonged the latency to approach and attack pups, and suppressed the initiation of infanticide in both male and female infanticide voles."
"Intraperitoneal injection of OT promoted approach and retrieval in pup-care male voles, and inhibited infanticide in both male and female voles."

Zitate

"More oxytocin (OT) neurons in the paraventricular nucleus (PVN) were activated during pup caring than infanticide."
"Optogenetic activation of OT neurons in the PVN facilitated pup-caring in male and female mandarin voles."
"Optogenetic activation of PVN OT neuron projection terminals in the mPFC shortened the latency to approach and retrieve pups and facilitated the initiation of pup care, whereas inhibition of these projections had little effect."
"Optogenetic activation of PVN-mPFC OT projection terminals prolonged the latency to approach and attack pups and suppressed the initiation of infanticide, whereas inhibition of these projections promoted approach and infanticide."
"Intraperitoneal injection of OT promoted pup care and inhibited infanticide behavior."

Wichtige Erkenntnisse aus

PVN-mPFC OT projections modulates pup-directed pup care or attacking in virgin mandarin voles

by Li,L., He,Z.... um www.biorxiv.org 03-11-2024

https://www.biorxiv.org/content/10.1101/2024.03.06.583718v1

Tiefere Fragen

How do the neural mechanisms underlying pup care and infanticide behaviors differ between monogamous and non-monogamous rodent species?

In monogamous rodent species, such as the mandarin voles in the study, both males and females exhibit caregiving behaviors towards offspring. The neural mechanisms underlying pup care in monogamous species involve the activation of oxytocin (OT) neurons in the paraventricular nucleus (PVN), which play a crucial role in promoting parental care behaviors. On the other hand, infanticide behaviors in monogamous species are regulated by different neural circuits, leading to aggression towards offspring. In the study, it was found that more OT neurons in the PVN were activated during pup care than during infanticide, indicating a differential neural response to these behaviors in monogamous species.
In non-monogamous rodent species, the neural mechanisms underlying pup care and infanticide behaviors may differ. Non-monogamous species may not exhibit as strong parental care behaviors as monogamous species, and the neural circuits regulating these behaviors may vary. For example, in non-monogamous species, the activation of OT neurons in the PVN may not play as significant a role in promoting parental care behaviors, and other neurotransmitter systems or brain regions may be more involved in regulating these behaviors. Additionally, non-monogamous species may exhibit different patterns of infanticide behavior, which could be regulated by distinct neural mechanisms compared to monogamous species.

What other brain regions and neurotransmitter systems, besides the OT system, might be involved in the regulation of pup-directed behaviors?

In addition to the OT system, several other brain regions and neurotransmitter systems may be involved in the regulation of pup-directed behaviors. The medial prefrontal cortex (mPFC) is one such brain region that plays a crucial role in attention switching, decision-making, and behavioral flexibility, making it potentially crucial for rapidly expressing pup care or infanticide behavior. The mPFC is highly activated during caregiving behaviors in rodents and humans, indicating its involvement in parental care.
Other neurotransmitter systems that may be involved in the regulation of pup-directed behaviors include dopamine, serotonin, and vasopressin. Dopamine, for example, is known to play a role in reward processing and motivation, which are essential components of parental care behaviors. Serotonin is involved in mood regulation and social behavior, and disruptions in the serotonin system have been linked to changes in parental care behaviors. Vasopressin, similar to OT, is a neuropeptide that has been implicated in social bonding and parental care behaviors in rodents.
The interactions between these neurotransmitter systems and brain regions, along with the OT system, likely contribute to the complex regulation of pup-directed behaviors in rodents and other species.

Could the modulation of the OT system be a potential therapeutic target for treating abnormal behaviors associated with certain psychological disorders in humans?

The modulation of the OT system holds promise as a potential therapeutic target for treating abnormal behaviors associated with certain psychological disorders in humans. OT is known to play a crucial role in social bonding, attachment, and parental care behaviors, and dysregulation of the OT system has been implicated in various psychiatric disorders.
For example, individuals with autism spectrum disorder (ASD) often exhibit difficulties in social interactions and bonding, which may be linked to alterations in the OT system. By modulating the OT system through pharmacological interventions or behavioral therapies that enhance OT release, it may be possible to improve social functioning and reduce symptoms of ASD.
Similarly, individuals with mood disorders, anxiety disorders, and postpartum depression may benefit from interventions targeting the OT system. OT has been shown to have anxiolytic and mood-regulating effects, and enhancing OT signaling could potentially alleviate symptoms of these disorders.
Overall, the modulation of the OT system represents a promising avenue for the development of novel therapeutic interventions for a range of psychological disorders characterized by abnormal social behaviors and bonding. Further research is needed to explore the specific mechanisms of action and potential treatment strategies involving the OT system.