Social domination increases neuronal survival in the brain of juvenile crayfishProcambarus clarkii

Abstract

SUMMARY Olfactory cues are among the sensory inputs that crayfish use in establishing dominance hierarchies. Throughout their lives, new neurons are continuously added into brain cell clusters 9 and 10, which contain somata of olfactory local and projection interneurons, respectively. Using markers for DNA synthesis (bromodeoxyuridine) and mitosis (phospho-histone-3), we tested juvenile crayfish (Procambarus clarkii) to examine effects of pairwise social experience on proliferation and survival of cells in these brain regions. Proliferating and mitotic cells appeared within restricted neurogenic areas in both clusters and in `tails' extending from them. These tails, embedded in tubulin-positive strands, are linked by a patch of cells. Neither cell proliferation nor mitotic activity was affected by social dominance. Cell survival of neuronal precursors was affected by dominance:compared to dominants, subordinates had fewer newborn cells surviving in cluster 9 after 14 days of social experience. Social experience also affected body growth rate, but the effect of social experience on neurogenesis remained when differences in body growth rate were statistically controlled. We conclude that social domination enhances survival of new olfactory interneuronal precursors compared to social subordination but not compared to social isolation.

Adult neurogenesis in the decapod crustacean brain: a hematopoietic connection?

“…2B). Some of these features in Procambarus clarkii have been confirmed in studies by others (Song et al. , 2007, 2009).…”

Adult neurogenesis in the decapod crustacean brain: a hematopoietic connection?

“…2B). Some of these features in Procambarus clarkii have been confirmed in studies by others (Song et al. , 2007, 2009).…”

Production of different phenotypes from the same genotype in the same environment by developmental variation

“…These observations suggest that even in size-matched clone-mates, slight initial physiological or behavioural differences can finally result in a broad range of phenotypes, probably by self-reinforcing circuits involving behaviour, sense organs, brain, hormone system and metabolism. This idea is corroborated by Song et al (Song et al, 2007), who observed higher survival of brain cell precursors in dominant crayfish compared to subordinates. The relationship of dominance and faster growth is well known from bisexual crayfish species but is usually attributed to genetic differences in food conversion and aggression (Reynolds, 1989).…”

Adult neurogenesis and cell cycle regulation in the crustacean olfactory pathway: from glial precursors to differentiated neurons

“…No Mphase labelling, however, has thus far been observed of cells in the migratory streams (Fig. 3G), neither in our preparations nor in the published images of others who have worked on neurogenesis in P. clarkii (Song et al 2007). A model that would fit these observations (summarised in Fig.…”

Adult neurogenesis in the decapod crustacean brain: a hematopoietic connection?

“…2B). Some of these features in Procambarus clarkii have been confirmed in studies by others (Song et al. , 2007, 2009).…”

Production of different phenotypes from the same genotype in the same environment by developmental variation

“…These observations suggest that even in size-matched clone-mates, slight initial physiological or behavioural differences can finally result in a broad range of phenotypes, probably by self-reinforcing circuits involving behaviour, sense organs, brain, hormone system and metabolism. This idea is corroborated by Song et al (Song et al, 2007), who observed higher survival of brain cell precursors in dominant crayfish compared to subordinates. The relationship of dominance and faster growth is well known from bisexual crayfish species but is usually attributed to genetic differences in food conversion and aggression (Reynolds, 1989).…”

Adult neurogenesis and cell cycle regulation in the crustacean olfactory pathway: from glial precursors to differentiated neurons

“…No Mphase labelling, however, has thus far been observed of cells in the migratory streams (Fig. 3G), neither in our preparations nor in the published images of others who have worked on neurogenesis in P. clarkii (Song et al 2007). A model that would fit these observations (summarised in Fig.…”

Adult neurogenesis in the decapod crustacean brain: a hematopoietic connection?

“…2B). Some of these features in Procambarus clarkii have been confirmed in studies by others (Song et al. , 2007, 2009).…”

Production of different phenotypes from the same genotype in the same environment by developmental variation

“…These observations suggest that even in size-matched clone-mates, slight initial physiological or behavioural differences can finally result in a broad range of phenotypes, probably by self-reinforcing circuits involving behaviour, sense organs, brain, hormone system and metabolism. This idea is corroborated by Song et al (Song et al, 2007), who observed higher survival of brain cell precursors in dominant crayfish compared to subordinates. The relationship of dominance and faster growth is well known from bisexual crayfish species but is usually attributed to genetic differences in food conversion and aggression (Reynolds, 1989).…”

Adult neurogenesis and cell cycle regulation in the crustacean olfactory pathway: from glial precursors to differentiated neurons

“…No Mphase labelling, however, has thus far been observed of cells in the migratory streams (Fig. 3G), neither in our preparations nor in the published images of others who have worked on neurogenesis in P. clarkii (Song et al 2007). A model that would fit these observations (summarised in Fig.…”