Social interactions influence dopamine and octopamine homeostasis in the brain of the ant Formica japonica

Abstract

SUMMARYIn ants, including Formica japonica, trophallaxis and grooming are typical social behaviors shared among nestmates. After depriving ants of either food or nestmates and then providing them with either food or nestmates, a behavioral change in type and frequency of social interactions was observed. We hypothesized that starvation and isolation affected levels of brain biogenic amines including dopamine (DA) and octopamine (OA) -neuromediators modifying various insect behaviors -and tested the relationship between brain biogenic amines and social behaviors of stressed ants. Ants starved for 7days contained lower brain DA levels and they did not perform trophallaxis toward nestmates. Feeding starved ants sucrose solution re-established trophallaxis but not brain DA levels. The performance of trophallaxis induced recovery of brain DA content to the level of untreated ants. Ants that were isolated for 2days displayed markedly increased OA levels, which following nestmate interactions, returned to levels similar to those of control (non-isolated) ants and ants isolated for 1h. We conclude that: (1) starvation reduced brain DA level but had no significant effect on brain OA (trophallaxis recovered the brain DA levels), and (2) isolation increased brain OA level but had no effect on brain DA (trophallaxis and grooming events recovered the brain OA levels). We suggest that social interactions with nestmates influenced brain biogenic amine homeostasis in stressed F. japonica.

Octopaminergic system in the brain controls aggressive motivation in the ant,Formica Japonica

“…On the other hand, our data demonstrated that, in the queens, even if OA level in the brain is kept high; aggressive motivation seems to be kept low to evoke just threat behavior, if activity of N-acetylation in the brain is enhanced. Our studies also suggest that the 5-HTergic and DAergic systems are not closely linked to motivating aggressive behavior, although the 5-HTergic system might be linked to an evoked aggression as shown by Kostowski et al [6], and DAergic system in the brain, on the other hand, is demonstrated to be linked to social interaction in the ant [5]. We also observed that social interaction maintains contents of biogenic amine in the brain.…”

“…Biogenic amines in the ant brain were measured using high-performance liquid chromatography (HPLC) with electrochemical detection (ECD). The detail of the HPLC-ECD system was described in our previous report [5]. In short, an ant was quickly frozen using liquid N 2 and the brain was dissected out in ice cold saline.…”

Biogenic Amines and Collective Organization in a Superorganism: Neuromodulation of Social Behavior in Ants

“…japonica [Wada-Katsumata et al, 2011] a ; P. dentata C. mus [Falibene et al, 2012] a ; P. dentata Predatory aggression F. japonica [Aonuma and Watanabe, 2012b] Production of oocytes and haploid egg laying, but not dealation, can be decreased by treatment with a tyrosine hydroxylase inhibitor, which leads to lowered DA titers. In honeybees, queen mandibular pheromone reduces DA levels of young workers inside the nest; decreased DA reduces locomotion, which may increase worker brood care [Beggs et al, 2007].…”

Behavioral diversity assisting obstacle navigation during group transportation in ant

“…In uncoordinated transportation, ants 15 pull a food item in opposite directions [8], resulting in slow-speed transportation 16 and/or frequently reaching a deadlock. In encircling coordinated transportation, ants 17 encircle a food item and the majority of members align at the side of the moving front 18 and pull it, whereas minor members align at the back and pull, lift, or push it. This 19 behavior achieves quick transportation, rarely reaching a deadlock.…”

“…The ants, F. japonica are widely distributed in Japan [13,14] and have been 43 investigated particularly with regard to landmark navigation [15], social 44 interaction [16,17], etc. Most ants of this species lives under open ground and 45 …”