Functional circuit architecture underlying parental behaviour

Abstract

SummaryParenting is essential for the survival and wellbeing of mammalian offspring but we lack a circuit-level understanding of how distinct components of this behaviour are orchestrated. Here we investigate how Galanin-expressing neurons in the medial preoptic area (MPOAGal) coordinate motor, motivational, hormonal and social aspects of parenting. These neurons integrate inputs from a large number of brain areas, whose activation depends on the animal’s sex and reproductive state. Subsets of MPOAGal neurons form discrete pools defined by their projection sites. While the MPOAGal population is active during all episodes of parental behaviour, individual pools are tuned to characteristic aspects of parenting. Optogenetic manipulation of MPOAGal projections mirrors this specificity, affecting discrete parenting components. This functional organization, reminiscent of the control of motor sequences by pools of spinal cord neurons, provides a new model for how discrete elements of a social behaviour are generated at the circuit level.

Histone deacetylase inhibitor treatment promotes spontaneous caregiving behaviour in non‐aggressive virgin male mice

“…In the present study, we examined the expression of two IEG transcripts ( cFos and Npas4 ) that show stimulus‐driven transient expression in the brain. Although Npas4 expression has never been examined in response to pup cues, cFos expression (both mRNA and protein) has been investigated extensively in response to pup cues in both male and female mice, as well as female rats . Our data indicate a near global induction of cFos in response to pup cues, and this finding is consistent with other reports that have identified the mPOA, AHN, VMN and dBNST as regions that are sensitive to pup stimulation.…”

“…Thus, motivation to approach pups, regardless of the intent to kill or care, is associated with cFos induction. In support of this idea, optogenetic stimulation of mPOA neurones that project to the VTA increased motivation to reach pups (by climbing over a physical barrier) in male and female mice even though males killed pups once they came into contact with them . Therefore, perhaps it is not surprising that cFos expression alone in the VTA does not predict the intention to kill or care for pups.…”

“…In females, seminal work uncovering the neural mechanisms that gate infant stimulation of the maternal neural circuit was conducted in postpartum rats and recent work has replicated some of these findings in mice . Importantly, motivation to care for offspring first occurs around the time of birth.…”

“…In females, seminal work uncovering the neural mechanisms that gate infant stimulation of the maternal neural circuit was conducted in postpartum rats 7 and recent work has replicated some of these findings in mice. 8,9 Importantly, motivation to care for offspring first occurs around the time of birth. In non-parental animals, infants activate hypothalamic regions known to regulate anxiety/escape/attack behaviours such as the anterior hypothalamic nucleus (AHN) and ventromedial nucleus of the hypothalamus (VMN).…”

Inclusion of females does not increase variability in rodent research studies

“…One consequence of pathway differences underlying similar behaviors is that the same perturbations of neurochemicals or environmental factors can have opposing effects in males and females[39–41]. Recent work on parental behavior reveals that some pathways contribute similarly to both maternal and paternal behaviors in mice[42,43], while other circuits and neuropeptide expression patterns differ in important ways[44]. Perhaps a more important view is that studies assessing mechanisms underlying behavior in both sexes are so rare that we often have little idea of the magnitude and relevance of differences[45].…”