The characteristics of the intragroup behavior of rhesus macaques and hamadryas baboons during the realization of food motivation in a competitive situation]

The aim of the present work is to consider the specific interrelations in "family" units of macaques (Macaca mulatta) and baboons (Papio hamadryas) during food-getting reactions in competitive conditions. Detailed analysis of dyadic interactions revealed that competing partners demonstrate more various types of behaviour tactics at the initial stage of learning. At the final one, only males of both investigated species performed instrumental reactions and received the food reward. All females demonstrated much more vocal reactions in comparison with males. Thus the variety of competing interactions between heterosexual partners, learning and possibility to realize its motivation correspond ro novelty of experimental situation and degree of intraspecies social subordination.     

The neuronal activity of the caudate nucleus in monkeys during the realization of delayed behavior]

A greater part (64%) of recorded neurones of the caudate nucleus head changed its activity at various stages of fulfillment by the monkey of the task of delayed spatial choice. Most of them (46.5% of all studied) reacted at key depressing and/or taking food from the feeder. During signal presentation and with delay the frequency of impulse activity changed respectively in 17% and 14% of the studied neurones. Besides, 2 neurones had spatially-selective activity in the instructive period of the program. It can be suggested that caudate neurones participate in realization of the delayed behaviour not only during motor response fulfillment but in the instructive period as well--at the stage of perception and processing of the visual information and its storing in short-term memory.     

Troop movement and food habits of white-faced monkeys in a tropical-dry forest

Home-range, movement and activity patterns and diet of a group of 16 white-faced monkeys (Cebus capucinus) were studied in a Costa Rican tropical dry forest at the end of the dry season (March and April) of 1982. The troop used an area of .67 km2 and moved an average of 4.5 km +/- 0.6 daily. Three basic daily activities were identified: resting, moving and feeding. Resting was greatest between 1000-1500 hours. Movement, which was strongly correlated with feeding, occurred most between 0500-0900 hrs and 1300-1800 hrs. The primates were omnivores, feeding on parts of 27 species of plants, four species of insects and an Anolis lizard.     

Reaching behavior of rats during realization of a lateralized motor food skill

Adult Wistar rats were trained to obtain food pellets from a narrow horizontal tube with a preferred forepaw. The feeder was equipped with five photoelectric sensors with 5-mm spacing. The following parameters were recorded: total number of movements performed for a given task, amplitude (depth) of each movement, number of anticipatory movements performed with different amplitudes, and amplitude of a successful movement. It was shown that in rats with good skill acquisition, a successful food extraction was preceded by a series of differently organized sequence of preliminary movements. In some rats, such a series consisted of initial non-deep attempts followed by movements with high amplitude, whereas in other animals, it was represented, mainly, by deep attempts. Both groups of animals terminated the series by grasping and extracting food from a long distance. It is suggested that the observed organizations of the lateralized food-getting behavior of rats under the given experimental conditions represent fixed (stereotyped) action patterns.     

A comparative study of positional behavior in three species of tamarin monkeys

Tamarins of the genusSaguinus are small-bodied New World monkeys that exhibit clawlike or modified nails. Patterns of positional behavior and habitat utilization are presented for three species,Saguinus fuscicollis, S. geoffroy, andS. mystax. These data were collected on free-ranging tamarin populations in Panama and Peru. Despite considerable differences in body weight, all three species exhibited very similar patterns of positional behavior, with quadrupedal bounding and running accounting for 43 – 52% of travel time. Leaping was the second most common locomotor activity and accounted for 31 – 41% of travel. Although each species leaped principally on small supports in the perimeter of the tree crown, approximately 20% of all leaps inS. fuscicollis involved moderate to large sized vertical trunks located in the undercanopy. Leaping between trunks was rare in the two larger tamarin species. Measurements taken on live wild-trapped adults reveal that compared toSaguinus geoffroyi andS. mystax, S. fuscicollis is characterized by a long legspan and an especially long armspan. It is proposed that inS. fuscicollis, elongated forelimbs play an important role in maneuvering and rotating the body during the in-air phase of trunk-to-trunk leaping, and increase the breaking distance needed to decelerate the body upon impact. Additional relationships between body size, substrate preference, and positional behavior in callitrichines are discussed.     

Activity of neurons in the anterolateral region of the rabbit motor cortex during taking food and nonfood objects in instrumental behavior

We showed earlier that only 2-4% of N-neurons in the rabbit's anterolateral ("masticatory") motor cortex (AC) that are being specialized in relation to Newly formed acts (such as pressing the pedal, approaching the pedal) during the elaboration of instrumental food-acquistion behavior. The majority of neurons in this area are O-neurons that are specialized in relation to the Older acts formed long before the acquisition of instrumental behavior: mostly taking of food. It was shown also that electrical stimulation of this area produced jaw movements. It might seem reasonable to propose that the number of N-neurons may be increased in this area if pedal pressing in substituted with instrumental act like seizure and pulling a ring that is more corresponding to the "projectional property" of the AC. Here we show that the number of N-neurons in rabbit's AC remains constant -3.4%, even is the animals that were trained to pull a ring instead of pressing a pedal. Thus, we assume that the small number of N-neurons is the stable property of the AC. However, the role of the AC in the subserving of the behavior does not remain the same. Much more AC units (O-neurons) were activated in the ring pulling than in the pedal pressing instrumental act.     

Effect of an enkephalin-like tetrapeptide on the food instrumental behavior of rats

An enkephalin-like tetrapeptide (subcutaneous, intraperitoneal and intraventricular injections) disturbs the goal-oriented food instrumental behavior of rats by decreasing the number of adequately performed instrumental reactions. In addition to these disorders, intraventricular microinjections entail an increase in the number of inadequate, incomplete behavioral reactions. Besides, injection of the tetrapeptide evokes specific disorders of motor activity, which manifest in the occurrence in rats of stretches, "duck-like step", motor stereotypy, arching of the tail, changes in the tone of abdominal muscles, etc. The tetrapeptide effects described were not inhibited by narcan, remaining unchanged for 3.5-5 months following a single injection of the tetrapeptide.     

Activity of the neostriatum neurons in monkeys during operant behavior

Monkeys (Macaca nemestrina) were trained to perform an operant task which included the following stages: bimanual movement to a visible target in response to a start signal, selection of the left or right operating hand according to the visual conditioning signal, careful movement of the selected hand, movements of fingers of the same hand, and taking of a reward. The spike activity was recorded simultaneously from five or six neurons in the caudate nucleus (Cd) head. Most of the Cd neurons were activated during the taking of a reward, the analysis of conditioning signals, and visually controlled movements. It has been found that the same neuron of the Cd may be activated in different ways during different components of the behavioral program, depending on the complexity of the conditioning signals and the correct versus incorrect selection of an operating hand. It is concluded that the Cd neurons have no functional specialization and that they take part in mechanisms preceding a movement or accompanying it, but not correlating with the form of its realization.Translated from Neirofiziologiya, Vol. 25, No. 2, pp. 132–140, March–April, 1993.     

The food and feeding habits of Tilapia species in the Lagos Lagoon

The food of Tilapia mariae (Boulenger), Tilapia guineensis * (Bleeker) and Tilapia melano-theron melanotheron * (Rupell) were investigated. It is shown that T. guineensis and T. m. melanotheron which were the more abundant species had similar food habits. The intensity of feeding of both species and the possible competition for food between them are discussed.     

Unaltered instrumental learning and attenuated body-weight gain in rats during non-rotating simulated shiftwork

Exposure to shiftwork has been associated with multiple health disorders and cognitive impairments in humans. We tested if we could replicate metabolic and cognitive consequences of shiftwork, as reported in humans, in a rat model comparable to 5 wks of non-rotating night shifts. The following hypotheses were addressed: (i) shiftwork enhances body-weight gain, which would indicate metabolic effects; and (ii) shiftwork negatively affects learning of a simple goal-directed behavior, i.e., the association of lever pressing with food reward (instrumental learning), which would indicate cognitive effects. We used a novel method of forced locomotion to model work during the animals' normal resting period. We first show that Wistar rats, indeed, are active throughout a shiftwork protocol. In contrast with previous findings, the shiftwork protocol attenuated the normal weight gain to 76 ± 8 g in 5 wks as compared to 123 ± 15 g in the control group. The discrepancy with previous work may be explained by the concurrent observation that with our shiftwork protocol rats did not adjust their between-work circadian activity pattern. They maintained a normal level of activity during the "off-work" periods. In the control experiment, rats were kept active during the dark period, normally dominated by activity. This demonstrated that forced activity, per se, did not affect body-weight gain (mean ± SEM: 85 ± 11 g over 5 wks as compared to 84 ± 11 g in the control group). Rats were trained on an instrumental learning paradigm during the fifth week of the protocol. All groups showed equivalent increases in lever pressing from the first (3.8 ± .7) to the sixth (21.3 ± 2.4) session, and needed a similar amount of sessions (5.1 ± .3) to reach a learning criterion (≥ 27 out of 30 lever presses). These results suggest that while on prolonged non-rotating shiftwork, not fully reversing the circadian rhythm might actually be beneficial to prevent body-weight gain and cognitive impairments.     

Functional asymmetry of the frontal cortex and lateral hypothalamus of cats during food instrumental conditioning

The synchronism and latency of auditory evoked potentials (EP) recorded in symmetric points of the frontal cortex and lateral hypothalamus of cats were measured at different stages of instrumental food conditioning and after the urgent transition to 30% reinforcement. Correlation coefficients between EPs in the cortex and hypothalamus were high (with left-side dominance) at the beginning of the experiments, when food motivation was high, and during the whole experiments in cases of high-probability of conditioned performance. Analysis of early positive P55-80 EP component showed that at all conditioning stages the peak latency of this component was shorter in the left cortical areas than in symmetrical points, whereas in the hypothalamus the shorter latency at the left side was observed at the stage of unstable conditioned reflex, and at the stage of stable reflex the latency of the studied component was shorter at the right side. During transition to 30% reinforcement, the latency was also shorter in the right hypothalamus. It is suggested that the high left-side correlation between the hypothalamus and cortex was associated with motivational and motor component of behavior rather than reflected the emotional stress induced by transition to another stereotype of food reinforcement (30%).     

Behaviour of one-year-old rhesus monkeys in a strange situation

When one-year old rhesus monkeys and their mothers were removed from the colony to a strange situation, infants' activity was initially low compared with behaviour six days later. Although absolute values did not differ between males and females, correlations did. That is, three days after return to the colony, correlations with baseline colony behaviour were significantly positive for females, while males had one significantly negative correlation. On the other hand, males had more significant correlations than females when behaviour in the strange situation was correlated with colony scores. Of the six individuals that had adverse early experience, five showed extreme behaviour. The exception was CT, son of a female with a very low ‘excitable’ score. In fact for all males, mothers' colony scores were significantly correlated with sons' behaviour in the strange situation.     

Food aversion learning in Japanese monkeys (Macaca fuscata). A strategy to avoid a noxious food

Japanese monkeys consumed two kinds of food, the novel almonds and the familiar sweet potatoes, simultaneously, and then received a cyclophosphamide injection (20 mg/kg) intravenously. As the food-poison pairing was repeated, they first avoided the novel food completely, and then came to suppress eating the familiar one. During the subsequent extinction tests, the aversion to the familiar food was extinguished rapidly, whereas the aversion to the novel one was retained more than 2 months. In food aversion learning in a mixed situation, monkeys have a strategy to avoid a noxious food on the basis of the novelty of the food.     

Odour learning and decision-making during food collection in the leaf-cutting antAcromyrmex lundi

Summary Recruited workers of the leaf-cutting antAcromyrmex lundi learn the odour of the food fragment initially carried by a successful scout, and use this cue as a decision criterion during food collection. Citral, a natural deterrent odour, can also be associated as a food signal, showing how powerful olfactory learning is in this species. The role of both food-odour learning and a previously reported leaf-marking pheromone during diet selection by leaf-cutting ants is discussed.     

Stochastic simulation of the instrumental reflex in probability learning

A method of computer imitation modelling is worked out of the process of instrumental reflex elaboration allowing to prognosticate the rate of learning at various combinations of probabilistic medium parameters and individual properties of the learning subject. By means of imitating modelling it is easy to find out the localization of the optima and pessima zones in the space of parameters influencing the learning. For building the model the empiric data are not required--they are used only for checking the obtained results. Therefore the conformity obtained with the literature data and the results of own studies allows to suggest that firstly, the worked out model possesses a good forecasting power and secondly, it can be used for studying such conditions of learning for which the appropriate experimental material is not yet collected.     

The food and feeding habits of the Torrent frog, Amolops larutensis

The stomach contents of 661 Amolops larutensis (Blgr.) showed that this frog feeds on a wide range of terrestrial and aquatic animals of which insects form the greater part. Feeding was confined to the rocks and vegetation bordering the water-falls. Although adult frogs were capable of ingesting large prey up to a maximum length of 47.0 mm, they showed a definite preference for prey animals within the size-range of 1 to 6.5 mm length. No clear seasonal variation in the diet was found and it was suggested that the monthly fluctuations in the amount and type of prey ingested depend largely on the activity of the prey.