Real-time in vivo simultaneous measurements of nitric oxide and oxygen using an amperometric dual microsensor.

This paper reports a real-time study of the codynamical changes in the release of endogenous nitric oxide (NO) and oxygen (O(2)) consumption in a rat neocortex in vivo upon electrical stimulation using an amperometric NO/O(2) dual microsensor. Electrical stimulation induced transient cerebral hypoxia due to the increased metabolic demands that were not met by the blood volume inside the stimulated cortical region. A NO/O(2) dual microsensor was successfully used to monitor the pair of real-time dynamic changes in the tissue NO and O(2) contents.

Cellular basis of neurogenesis in the brain of crayfish, Procambarus clarkii: Neurogenic complex in the olfactory midbrain from hatchlings to adults.

Neurogenesis in the central olfactory pathway of decapod crustaceans persists throughout life. Here we describe the structural basis of neurogenesis within the olfactory deutocerebrum of the crayfish Procambarus clarkii from hatchlings to adults. Using a proliferation marker and immunostaining, we found that throughout development each hemibrain contains a neurogenic complex consisting of five parts: two proliferation zones, each within the neuronal soma clusters containing local or projection interneurons, a tail of proliferating cells extending from each proliferation zone, and an elongated clump of cells where the two tails meet.

Social domination increases neuronal survival in the brain of juvenile crayfish Procambarus clarkii.

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.

The effects of social experience on the behavioral response to unexpected touch in crayfish.

Crayfish fight and form a dominance hierarchy characterized by a pattern of repeated agonistic interactions between animals with a consistent outcome of winner and loser. Once a dominance hierarchy is established, dominant animals display an elevated posture with both claws held laterally and forward, whereas subordinate animals display a more prone posture with both claws extended forward and down. Dominant animals behave aggressively towards the subordinate opponent, often approaching and attacking, whereas subordinate animals behave submissively by tailflipping and retreating.