The septal forebrain and the inhibitory modulation of attack and defense in the rat. A review.
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Concurrent use of alcohol and tobacco is common among adolescents, yet little is known about the developmental patterns of concurrent use, or the consequences associated with such patterns during young adulthood. Using data collected at six time points during 1985-1995 as part of an evaluation of a school-based substance abuse prevention program in California and Oregon, this study used latent growth mixture modeling to identify five distinct developmental trajectories of concurrent use of alcohol and tobacco from ages 13-23 in a cohort of 5873 individuals and compared these distinct groups with respect to demographic characteristics and young adult outcomes (at age 23 and age 29). Results suggest that while it is common during adolescence to drink but not smoke, it is very unusual to smoke and not drink. Compared to young people who smoked and drank consistently throughout their teens and early twenties, those who drank consistently but smoked only occasionally or dramatically decreased their smoking over time had lower rates of deviant behavior and predatory violence at age 23 and were less likely to have a history of arrest and substance use problems by age 29. This close examination of concurrent use of alcohol and cigarette use from ages 13-23 further accentuates the importance of curbing smoking behavior among adolescents before it becomes habitual.
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In addition to being frugivorous, Cebus and Saimiri stand out among the New World primates of similar body size in being heavily dependent on animal matter for protein (faunivory). A detailed description of the morphology and behavior of the two genera is presented with the object of evaluating the interaction and respective contributions of morphological and behavioral adaptations to foraging patterns. Our conclusions include the following: First, body size is extremely important in explaining the observed variation in diet. Second, the emphasis on faunivory is facilitated more by behavioral than by morphological specialization. Third, whatever morphological specializations are present, particularly in Cebus, are probably favored by diet at the most food-depauperate time of year. Fourth, although morphology may well reveal what a primate may potentially eat, to map this potential onto actual diet requires a detailed knowledge of its natural ecosystem. Finally, we consider whether the behavioral data support the tenuous morphological evidence for grouping Cebus and Saimiri within the clade Cebinae.
We examined the effect of the selective serotonin 2A (5-HT(2A)) receptor antagonist 7-[4-[2-(4-fluoro-phenyl)-ethyl]-piperazine-1-carbonyl]-1H-indole-3-carbon itrile HCl (EMD 281014) [Bartoszyk, G.D., van Amsterdam, C., Bottcher, H., Seyfried, C.A., 2003. EMD 281014, a new selective serotonin 5-HT2A receptor antagonist. Eur. J. Pharmacol. 473, 229-230.] on change in affect following predator stress. Predator stress involved a 5 min unprotected exposure of rats to a domestic cat. Behavioral effects of stress were evaluated with hole board, plus maze, light/dark box and acoustic startle tests 1 week after stress. Predator stress increased anxiety-like behavior in the plus maze, light/dark box, and elevated response to acoustic startle. EMD 281014 (0.001, 0.01, 0.1, 1 or 10 mg/kg) and vehicle injection (ip) occurred either 10 min after predator stress (prophylactic testing), or 90 min prior to behavioral testing for the effects of predator stress (therapeutic testing 1 week after predator stress). In prophylactic testing, EMD 281014 prevented stress potentiation of startle in a dose dependent manner, though the most effective doses were midrange (0.01 and 0.1 mg/kg). Prophylactic administration of EMD 281014 also prevented stress-induced increase of open arm avoidance in the plus maze in a clear dose dependent manner (from 0.01 mg/kg onward). In therapeutic testing, EMD 281014 had no clear drug dependent effects on stress elevation of startle or on behavior of stressed rats in the elevated plus maze. Finally, EMD 281014 did not block the effects of stress on behavior in the light/dark box when given prophylactically or therapeutically. Findings implicate 5-HT(2A) receptors in initiation of some but not all lasting changes in anxiety-like behavior following predator stress. Potential clinical significance of findings are discussed.
Nonspecific lesion and stimulation methods have suggested that the hypothalamus is critical for the expression of defensive behavior, although the organization of neural circuits mediating such behavior is unclear. In the rat hypothalamus, we found that increased Fos levels were restricted to specific cell groups following presentation of a stimulus (predator) known to elicit partly innate defensive responses. The dorsal premammillary nucleus showed the most striking increase in Fos levels, and cell body-specific chemical lesions therein virtually eliminated two major components of defensive behavior but increased exploratory behavior, suggesting that this caudal hypothalamic nucleus plays a critical role in the expression of behavioral responses sometimes critical for survival of the individual. We have previously shown that the Fos-responsive cell groups in the medial hypothalamus are interconnected in a neural system distinct from those mediating reproductive and ingestive behaviors.
Plants genetically modified to express Galanthus nivalis agglutinin (GNA) have been found to confer partial resistance to homopteran pests. Laboratory experiments were conducted to investigate direct effects of GNA on larvae of three species of aphid predators that differ in their feeding and digestive physiology, i.e. Chrysoperla carnea, Adalia bipunctata and Coccinella septempunctata. Longevity of all three predator species was directly affected by GNA, when they were fed a sucrose solution containing 1% GNA. However, a difference in sensitivity towards GNA was observed when comparing the first and last larval stage of the three species. In vitro studies revealed that gut enzymes from none of the three species were able to break down GNA. In vivo feed-chase studies demonstrated accumulation of GNA in the larvae. After the larvae had been transferred to a diet devoid of GNA, the protein stayed present in the body of C. carnea, but decreased over time in both ladybirds. Binding studies showed that GNA binds to glycoproteins that can be found in the guts of larvae of all three predator species. Immunoassay by Western blotting of haemolymph samples only occasionally showed the presence of GNA. Fluorescence microscopy confirmed GNA accumulation in the midgut of C. carnea larvae. Implications of these findings for non-target risk assessment of GNA-transgenic crops are discussed.
Shark populations are declining globally, yet the movements and habitats of most species are unknown. We used a satellite tag attached to the dorsal fin to track salmon sharks (Lamna ditropis) for up to 3.2 years. Here we show that salmon sharks have a subarctic-to-subtropical niche, ranging from 2 degrees to 24 degrees C, and they spend winter periods in waters as cold as 2 degrees to 8 degrees C. Functional assays and protein gels reveal that the expression of excitation-contraction coupling proteins is enhanced in salmon shark hearts, which may underlie the shark's ability to maintain heart function at cold temperatures and their niche expansion into subarctic seas.
In contemporary foraging societies men typically hunt more than women. This observation has played an important role in many reconstructions of hominid evolution. The gender difference in human hunting, likely a product of both ecological and cultural factors, is mirrored by a similar sex difference among nonhuman primates. Existing explanations of such primate behavioral dimorphism are augmented by the recognition of an additional factor that may contribute to differences between males and females in the value of meat. Episodic female immunosuppression is a normal part of reproduction. Because meat is a source of pathogens, females can be expected to exhibit less constant attraction to meat. Sexual dimorphism in the attraction to meat may then contribute to dimorphic foraging specializations, a divergence that is likely augmented by the differential value of insectivory across the sexes. With the rise of cultural transmission of foraging knowledge, dimorphic foraging behaviors would have been reinforced, creating a more comprehensive gender-based division of labor.
Predation directly changes the demographics of prey, generally through a numerical decrease. An indirect effect of predators is alteration of movements and spatial patterns of prey. The relationship between these direct and indirect effects can be tested by excluding predators. Home range size of white-footed mice (Peromyscus leucopus) decreased and home range overlaps increased in the absence of predators. Home range size and overlaps of meadow voles (Microtus pennsylvanicus) did not change despite an increase in vole density. P. leucopus had significantly lower interspecific home range overlaps with M. pennsylvanicus than intraspecific overlaps. The changes in P. leucopus spatial behavior may be an indirect effect of predator exclusion resulting from the increase in M. pennsylvanicus densities.
A hypothesis that size selection of prey by predators elicits size-specific responses from prey was examined. Freshwater snails, Pomacea canaliculata, ages 1, 3, 7, 15, 30, or 60 days, were given an extract of 3-day-old snails, and 3-day-old snails were given extracts of snails of the otherages oreggs. Snails 15 days or younger crawled out of the water in response to the 3-day-old snail extract, but older ones did not. The 3-day-old snails responded to the extracts of snails of all examined ages, but not to the extract of eggs. Snails of four size classes, 3-days-old, small (shell lengths 8-12 mm), medium (13-20 mm), and large (>28 mm) were given extracts of snails of each of these four classes. The 3-day-old snails crawled out of the water in response to the extract of 3-day-old snails, but showed a lower or no response to other extracts. Larger snails buried themselves in the soil in response to the extract of snails of similar sizes. These responses are discussed in the context of the evolution of the snail's avoidance behavior in response to the size-dependent prey choice by the predator.
The persistence of Müllerian mimicry and geographically distinct wing patterns, as observed in many Heliconius species (Lepidoptera: Nymphalidae), is difficult to explain from a predator's perspective: predator selection against locally rare patterns must persist despite avoidance learning. Maintaining spatial color-pattern polymorphism requires local pattern avoidance, fine-scale discrimination among similar wing patterns, and repeated attacks on novel color patterns. I tested for these behaviors by presenting 80 adult rufous-tailed jacamars (Galbula ruficauda) with three morphs of Heliconius butterflies, and then presenting the same suite of butterflies to 46 of these jacamars between four and 429 days later. These trials offer the first direct evidence of the selective predator behavior required to maintain aposematic polymorphism: jacamars avoid local aposematic morphs while repeatedly attacking similar but novel morphs over time.
Conspicuous sonic click sounds were recorded in the presence of cod (Gadus morhua), together with either harp seals (Pagophilus groenlandicus), hooded seals (Cystophora cristata) or a human diver in a pool. Similar sounds were never recorded in the presence of salmon (Salmo salar) together with either seal species, or from either seal or fish species when kept separately in the pool. It is concluded that cod was the source of these sounds and that the clicks were produced only when cod were approached by a swimming predatorlike body. The analyzed click sounds (n = 377) had the following characteristics (overall averages +/- S.D.): peak frequency = 5.95 +/- 2.22 kHz; peak-to-peak duration = 0.70 +/- 0.45 ms; sound pressure level (received level) = 153.2 +/- 7.0 dB re 1 microPa at 1 m. At present the mechanism and purpose of these clicks is not known. However, the circumstances under which they were recorded and some observations on the behavior of the seals both suggest that the clicks could have a predator startling function.
Recent research has shown that bursts of approximately 20 Hz fast waves are elicited in rhinencephalic cortex in rats by the odors of a number of different organic solvents and of components of the secretions of predators such as the weasel and the fox. We now show that a number of phytochemicals (benzyl alcohol, carvacrol, eucalyptol, and salicylaldehyde) will elicit fast wave bursts of about 20 Hz in the rat pyriform cortex. Additional organic solvents (carbon tetrachloride, chloroform, diethyl ether, 1, 2-dimethoxyethane, n-heptane, mesitylene, methylcyclohexane, and commercial gasoline and kerosene, but not N,N-dimethylformamide or dimethyl sulfoxide) and another component of fox secretions (isopentenylmethyl sulfide) were also effective. Many of these compounds will also elicit fast wave bursts of about 20 Hz in the dentate gyrus. The effectiveness of benzyl alcohol, camphor, carvacrol, eucalyptol, isopentenylmethyl sulfide, 2-propylthietane, salicylaldehyde, toluene, and trimethylthiazoline (all of which elicit rhinencephalic fast waves in rats) in suppressing feeding in various small herbivores suggests that the recording of odor-induced rhinencephalic fast waves may provide an easy means of identifying new antifeedants. We found no evidence that the bursts of 20-Hz activity seen in the rat rhinencephalon were kindling-induced seizure-like reactions of the olfactory brain to the vapors of toxic chemicals.
We evaluated larval prey capture as a "behavioral biomarker" of contamination by examining feeding behavior of larval mummichogs (Fundulus heteroclitus) from many different sites, including a severely contaminated "Superfund" site, moderately contaminated sites, and reference areas. Prey capture ability was related to sediment contaminant levels. The levels of contaminants at a site were highly correlated with each other, so that the impact of individual contaminants was confounded. The number of captures of brine shrimp by mummichog larvae from all sites was highly variable, but significant negative correlations of prey capture were seen with mercury, lead, zinc, cadmium, and PCBs. As observed previously with adults, polyaromatic hydrocarbons (PAHs) did not appear to impair prey capture ability. The only site in which prey capture rates of 8-day old larvae were severely affected was the most highly contaminated Superfund site, Berry's Creek, NJ. This implies that larval prey capture is not as sensitive a behavioral biomarker for contamination as adult behavior studied previously.
The wolf spider, Pardosa milvina, displays effective antipredator behavior (reduced activity) in the presence of silk and excreta cues from adults of another cooccurring wolf spider, Hogna helluo. However, Pardosa and Hogna engage in size-structured intraguild predation, where Pardosa may be either the prey or predator of Hogna. We tested the ability of adult female Pardosa to vary antipredator responses toward kairomones produced by Hogna that vary in size. Hogna were maintained on filter paper for 24 hr. We then presented the paper to adult female Pardosa simultaneously paired with a blank sheet of paper. One treatment had two sheets of blank paper to serve as a control. The Hogna stimulus treatments were as follows (N = 15/treatment): (1) 1 Hogna half the mass of Pardosa; (2) 1 Hogna of equal mass of a Pardosa; (3) 1 adult Hogna, 30 times the mass of Pardosa; and (4) 8 Hogna each 0.25 the mass of Pardosa. Pardosa decreased activity in the presence of kairomones from Hogna of equal or larger size, but showed no change in activity in the presence of a blank control or from a single Hogna smaller than itself. Pardosa showed a reduction in activity in the presence of cues from eight small Hogna. Pardosa avoided substrates with adult Hogna cues, but showed no avoidance response to any other treatment. These results suggest that Pardosa is showing graded antipredator behavior relative to the quantity of predator kairomones present rather than directly discriminating among the different sizes of the predator.
The neural systems that control escape behavior have been studied intensively in several animals, including mollusks, fish and crayfish. Surprisingly little is known, however, about the activation and the utilization of escape circuits during prey-predator interactions. To complement the physiological and anatomical studies with a necessary behavioral equivalent, we investigated encounters between juvenile crayfish and large dragonfly nymphs in freely behaving animals using a combination of high-speed video-recordings and measurements of electric field potentials. During attacks, dragonfly nymphs rapidly extended their labium, equipped with short, sharp palps, to capture small crayfish. Crayfish responded to the tactile stimulus by activating neural escape circuits to generate tail-flips directed away from the predator. Tail-flips were the sole defense mechanism in response to an attack and every single strike was answered by tail-flip escape behavior. Crayfish used all three known types of escape tail-flips during the interactions with the dragonfly nymphs. Tail-flips generated by activity in the giant neurons were predominantly observed to trigger the initial escape responses to an attack, but non-giant mediated tail-flips were often generated to attempt escape after capture. Attacks to the front of the crayfish triggered tail-flips mediated either by the medial giant neuron or by non-giant circuitry, whereas attacks to the rear always elicited tail-flips mediated by the lateral giant neuron. Overall, tail flipping was found to be a successful behavior in preventing predation, and only a small percentage of crayfish were killed and consumed.
The study showed that the searching activity of P. japonica on cotton aphid Aphis gossypii decreased gradually with decreasing aphid density. When enough A. gossypii existed, P. japonica had a preferential searching and preying activity on the top of cotton plant. There was no significant difference in the preying activity of P. japonica at different positions of cotton plant, while the searching activity of the ladybird beetle was significantly lower on cotton M9101 than on cotton Zhongmian 13. The preying behavior of P. japonica was significantly correlated with the density and distribution of A. gossypii.