Differences in intermale aggression are accompanied by opposite vasopressin release patterns within the septum in rats bred for low and high anxiety

Abstract

Several studies suggest a role for arginine vasopressin (AVP), particularly in the lateral septum, in the regulation of intermale aggression. We used intracerebral microdialysis to monitor the local in vivo AVP release within the mediolateral septum of adult male Wistar rats bred for low (LAB) or high (HAB) anxiety-related behaviour during exposure to the resident-intruder test. LAB residents showed a significantly higher level of aggression than HAB residents, as reflected by more time spent with lateral threat, offensive upright and total aggressive behaviour as well as by more attacks and a shorter attack latency. Septal AVP release was significantly decreased in high-aggressive LAB males, while septal AVP release tended to increase in HAB males during resident-intruder test exposure. Moreover, LAB residents showed reduced neuronal activation of the lateral septum, as indicated by fewer c-Fos-positive cells, 1 h after the resident-intruder test. Pharmacological manipulation of the septal AVP system by local application of either synthetic AVP to LAB residents or the selective V1a receptor antagonist d(CH(2))(5)Tyr(Me)AVP to HAB residents did not change the level of aggression. However, application of AVP into the septum enhanced anxiety-related behaviour on the elevated plus-maze in LAB males, while local administration of the V1a receptor antagonist reduced social investigation in HAB males during the resident-intruder test. In conclusion, although AVP release patterns within the septum are dependent on the level of aggression, locally released AVP does not seem to be directly involved in the regulation of aggression, but rather modulates non-aggressive social and anxiety-related behaviours.

Maternal aggression in rodents: brain oxytocin and vasopressin mediate pup defence

“…This is probably linked to their overall high protective mothering style [58], and we even found that MA is positively correlated with the mothers' innate anxiety [58]. At first sight, this might sound contrary to findings in lactating rats and mice (see above), as well as to studies on aggression in males, where high anxiety is coupled with low aggression levels ( [72], mice: [76], HAB/LAB rats: [77,78]). However, in lactating HAB and LAB mothers, the high and low maternal aggressive behaviour, respectively, is apparently independent of preceding manipulations (surgery or injections).…”

The Neuropeptide Oxytocin Facilitates Pro-Social Behavior and Prevents Social Avoidance in Rats and Mice

“…After surgery, subjects were transferred to observation cages (rats: 40 Â 24 Â 36 cm, mice: 16 Â 22 Â 14 cm) and single housed till the end of the experiment. For social defeat, male rats selectively bred for low anxiety-related behavior (LAB) which show a reliable high level of inter-male aggression (Beiderbeck et al, 2007;Neumann et al, 2010), were used as residents. Experiments were performed in the first 3 h of the light or dark phase and conducted in accordance with the Guide for the Care and Use of Laboratory Animals of the Government of Oberpfalz and the guidelines of the NIH.…”

Nonapeptide influences on social behaviour: effects of vasotocin and isotocin on shoaling and interaction in zebrafish

“…In contrast to the phenotypic variation in social behaviour, there appears to be extensive regulatory overlap between species, with the nonapeptides oxytocin and vasopressin repeatedly demonstrated to be important regulators of multiple mammalian social behaviours including parental care (Pedersen, 2013), pair bonding (Winslow et al, 1993), affiliative behaviour (Madden & Clutton-Brock, 2011), social recognition (Bielsky et al, 2004), aggression (Albers et al, 2006) and even human social interactions (Meyer-Lindenberg et al, 2011). Furthermore, differences in nonapeptide release or receptor distribution have been strongly implicated in interspecies variation in social behaviour (Insel & Shapiro, 1992;Bester-Meredith et al, 1999), as well as intra-species population differences (Beiderbeck et al, 2007) and individual differences in social behaviour (Francis et al, 2000). However, sociality is far from a uniquely mammalian attribute and accumulating evidence implicates the nonapeptides in the regulation of social behaviour in other taxa (Moore et al, 2005; Godwin & Thompson, 2012).…”