Predatory hunting is an important type of innate behavior evolutionarily conserved across the animal kingdom. It is typically composed of a set of sequential actions, including prey search, pursuit, attack, and consumption. This behavior is subject to control by the nervous system. Early studies used toads as a model to probe the neuroethology of hunting, which led to the proposal of a sensory-triggered release mechanism for hunting actions. More recent studies have used genetically-trackable zebrafish and rodents and have made breakthrough discoveries in the neuroethology and neurocircuits underlying this behavior. Here, we review the sophisticated neurocircuitry involved in hunting and summarize the detailed mechanism for the circuitry to encode various aspects of hunting neuroethology, including sensory processing, sensorimotor transformation, motivation, and sequential encoding of hunting actions. We also discuss the overlapping brain circuits for hunting and feeding and point out the limitations of current studies. We propose that hunting is an ideal behavioral paradigm in which to study the neuroethology of motivated behaviors, which may shed new light on epidemic disorders, including binge-eating, obesity, and obsessive-compulsive disorders.
Animals ; Zebrafish ; Hunting ; Predatory Behavior/physiology* ; Neurons/physiology* ; Motivation

OBJECTIVETo test Candonocypris novaezelandiae (Baird) (C. novaezelandiae), sub-class Ostracoda, obtained from the Nile, Egypt for its predatory activity on snail, Biomphalaria alexandrina (B. alexandrina), intermediate host of Schistosoma mansoni (S. mansoni) and on the free-living larval stages of this parasite (miracidia and cercariae).

METHODSThe predatory activity of C. novaezelandiae was determined on B. alexandrina snail (several densities of eggs, newly hatched and juveniles). This activity was also determined on S. mansoni miracidia and cercariae using different volumes of water and different numbers of larvae. C. novaezelandiae was also tested for its effect on infection of snails and on the cercarial production.

RESULTSC. novaezelandiae was found to feed on the eggs, newly hatched and juvenile snails, but with significant reduction in the consumption in the presence of other diet like the blue green algae (Nostoc muscorum). This ostracod also showed considerable predatory activity on the free-living larval stages of S. mansoni which was affected by certain environmental factors such as volume of water, density of C. novaezelandiae and number of larvae of the parasite.

CONCLUSIONSThe presence of this ostracod in the aquatic habitat led to significant reduction of snail population, infection rate of snails with schistosme miracidia as well as of cercarial production from the infected snails. This may suggest that introducing C. novaezelandiae into the habitat at schistosome risky sites could suppress the transmission of the disease.

Animals ; Crustacea ; physiology ; Pest Control ; Pest Control, Biological ; Predatory Behavior ; Schistosoma mansoni ; Schistosomiasis mansoni ; prevention & control ; transmission

OBJECTIVETo investigate the effects of kidney-jing deficiency on the fertility of male mice and their male offspring.

METHODSThirty 6-week-old Kunming male mice and 300 female ones were randomly allocated to a blank control group, a model group and a kidney-tonifying group. The model and the kidney-tonifying groups were stressed by fear plus excessive sex to establish a kidney-jing deficiency model, and meanwhile the latter were given concentrated solution of Kidney-tonifying Recipe intragastrically at the dose of 0.16 ml/10 g. The control and the model groups were treated with physiological saline at the same dose for 21 days. Then all the male mice were mated with the healthy estrous females for 5 days. The sperm density and motility of each group of the male mice were examined, and their fertility was assessed by comparison of the pregnancy rate and the number of baby mice at each birth among their female mates. And the sperm density and motility of the male offspring were detected at 6 weeks.

RESULTSThe average number of baby mice at each birth in the model group was (7.00 +/- 1.73), significantly smaller than those in the control (9.43 +/- 1.27) and the kidney-tonifying group (8.80 +/- 1.10) (P < 0.05). The sperm density and motility of the model mice were (9.70 +/- 1.15) x 10(6) / ml and (66.72 +/- 10. 12) %, lower than those of the control ([14.08 +/- 1.15 x 10(6)/ ml and [81.75 +/- 3.56] %), and the kidney-tonifying group ([12.20 +/- 1.55] x 10(6)/ ml and [78.55 +/- 4.38] %) (P < 0.05). There was no significant difference between the latter two groups (P > 0.05). The sperm density and motility of the offspring of the model mice were (10.10 +/- 1.79) x 10(6)/ ml and (71.86 +/- 7.48) %, lower than those of the control ([15.30 +/- 1.83] x 10(6)/ ml and [79.86 +/- 5.68] %), and the kidney-tonifying group ([14.20 +/- 2.21] x 10(6)/ ml and [81.92 +/- 2.51] %) (P < 0.05), with no significant difference between the latter two groups (P > 0.05).

CONCLUSIONFear plus excessive sex could reduce the fertility of male mice and even that of their male offspring. And kidney-tonifying therapy could counteract this effect.

Animals ; Animals, Newborn ; Cats ; Disease Models, Animal ; Fear ; psychology ; Female ; Fertility ; drug effects ; physiology ; Litter Size ; drug effects ; Male ; Materia Medica ; pharmacology ; Mice ; Predatory Behavior ; physiology ; Random Allocation ; Sexual Behavior, Animal ; drug effects ; Sperm Count ; Sperm Motility ; drug effects ; Stress, Psychological ; physiopathology