A neutral odor may become a sexual incentive through classical conditioning in male rats

A neutral olfactory stimulus was employed as CS in a series of experiments with a sexually receptive female as UCS and the execution of an intromission as the UCR. Each experimental session lasted until the male ejaculated. The time the experimental subject spent in a zone adjacent to the source of the olfactory stimulus during the 10 s of CS presentation and the latency to enter that area were employed as measures of conditioning. In Experiment 1, the CS was always presented at the same location in the conditioning arena, bordering the site where the female became accessible. Conditioning resulted in a gradual increase in the time spent in the CS zone as well as in a reduction of the latency to enter it. In Experiment 2, the site of presentation of the CS was varied randomly from one side of the conditioning arena to another in order to assure that the subjects indeed associated the CS and not a particular location with access to a female. Again, the time spent in the CS zone increased and the latency to enter it was reduced by conditioning. Furthermore, after conditioning the CS was approached more than a neutral odor in a different context. In a third experiment one group of animals was randomly exposed to the CS to control for non-associative effects on performance. Another group was conditioned as in Experiment 2. The random presentation of the CS failed to enhance approach, while the paired UCS-CS had effects identical to those found in Experiment 2. In the last experiment, an olfactory CS⁻ was included. The CS⁺ and CS⁻ were presented in random order at random locations. Both the time spent in the CS⁺ and CS⁻ zones was increased, while the latency to enter the zone was significantly reduced only for the CS⁺. These data suggest that the subjects had partially learned to discriminate between the CS⁺ and the CS⁻, at most. The procedure employed in Experiments 2 and 3 seems to be the most promising for studies of sexual conditioning in male rats.     

男性对女性面孔吸引力的认知偏好: 来自ERP的证据

运用事件相关电位(ERPs)技术, 采用学习-再认实验任务, 探讨了男性对有、无吸引力女性面孔图片进行判断和再认时脑内时程的动态变化。行为数据结果表明, 男性对有吸引力女性面孔的反应时更长, 再认正确率更高。ERP结果发现, 有、无吸引力面孔诱发的ERP早成分和晚成分都存在显著差异, 最强效应出现在大脑皮层的中前部。在判断任务和再认任务中, 有吸引力的女性面孔都比无吸引力的女性面孔诱发出更大的ERP成分(分别为N300、P350~550ms和P160、N300~500ms、P500~700ms)。结果表明, 男性对有吸引力的女性面孔的判断和再认存在偏好。     

Hormones and competitive aggression in women

This study used diaries of competitive interactions to explore the relationship between hormones and competitive aggression in women. Thirty women completed approximately 10 diary entries each. In each entry, the women described a recent competitive interaction they had engaged in and noted whether it was expressed aggressively or through other tactics. Each woman received a score for the fraction of her competitive interactions that were expressed using physical aggression, verbal aggression, nothing overt, and so on. Hormones (total testosterone, free testosterone, androstenedione, estradiol, and cortisol) were measured in serum early in the follicular phase. Results indicate that women with low levels of androstenedione and total testosterone were less likely to express their competitive feelings overtly, while women with high levels of androstenedione were more likely than other women to express their competitive feelings through verbal aggression. Estradiol was unrelated to competitive tactics, but women with high estradiol levels reported fewer competitive interactions over athletics than did other women. Aggr. Behav. 29:107–115, 2003. © 2003 Wiley‐Liss, Inc.     

THE RAPE OF MEDUSA IN THE TEMPLE OF ATHENA: ASPECTS OF TRIANGULATION IN THE GIRL2

The relationship between the Greek goddess Athena and her father Zeus, together with the competitive hostility she displays towards other females, is presented as illustrating some previously neglected aspects of triangular developmental conflicts in the little girl. Literature on ‘the Oedipus complex in the female’ is reviewed and discussed. The mythological early histories of both Athena and the female monster Medusa are examined for the light they can shed on female developmental vicissitudes and resultant conflicts in both women and men. Unconscious split representations of women as assertive, phallic and dangerous, or alternatively passive, castrated and receptive result in defensive repudiation of the idea that a woman can be both actively assertive and also feminine and sexual. Athena's enraged action of transforming the beautiful young maiden Medusa into a monster as punishment for the ‘crime’ of having been raped in her temple is discussed as illustrating an outcome of the lack of resolution of the little girl's early triangular conflicts.     

The nucleus premammillaris ventralis (pmv) and aggressive behavior in the rat

Small bilateral electrolytic lesions placed just posterior of the ventromedial hypothalamic nucleus cause a strong increase in offensive behavior. The histology suggests that damage to the ventral premammillary nucleus is responsible for this effect. A summary of the neuroanatomical literature shows that this structure is connected to most other brain structures reported to be involved in offensive behavior.     

Aggressive behavior during the breeding season of adult female rhesus monkeys (Macaca mulatta)

The aggressive behavior of eight adult female rhesus living in a captive social group was studied prior to and during a breeding season extended by vasectomizing all the adult males in the group. Female reproductive status was ascertained by: recording all adult female-adult male copulations; detecting menstruation by vaginal swabbing; and analyzing serum progesterone levels by radioimmunoassay. Females showed more non-contact aggression during the breeding season, but wounding did not increase. Individual cycling females directed more frequent aggression to: particular adult males subordinate to them, subordinate females also in estrus, and (in a few cases) juveniles and infants.     

Septal damage in infant and adult rats: Effects on activity,emotionality, and muricide

Septal lesions produced signs of increased emotionality in the adult rat, the septal syndrome (hyperresponsiveness to handling; in the open field: decreased rearing and ambulation activity, increased defecation, deficient habituation) being more or less complete and more or less marked depending on the age at which the lesion was performed (7 days or 3 months), the extent of the lesion (restricted to the septum or extending to more ventrally located structures) and the environmental conditions in which the animals were reared (in groups or in isolation). All septal lesions provoked a similar and significant increase in the probability of occurrence of mouse-killing behavior, irrespective of age of operation, extent of lesion and kind of rearing environment. In a 24-hour actography starting at 11:30 a.m., the rats septalectomized at adult age were less active than controls during the initial period, while all septals were markedly more active than controls during the night period. Early septal lesions only transiently disrupted weight gain. The results obtained point to complex interactions between the effects of early brain damage and environmental conditions.     

Effects of mesolimbic dopamine depletion on responding maintained by cocaine and food.

The hypothesis that mesolimbic dopamine is selectively involved in cocaine reinforcement was investigated in the rat. Animals were trained under a multiple schedule in which responding was reinforced by intravenous cocaine (0.75 mg/kg/injection) or food (45-mg pellets) under fixed-ratio 15 schedule requirements in alternate 30-min components of a 2-hr daily session. Infusion of the catecholaminergic neurotoxin 6-hydroxydopamine, but not the vehicle solution, into the region of the nucleus accumbens and olfactory tubercle produced selective reductions in cocaine self-administration without significantly altering responding maintained by food within the same sessions. This effect was reproduced in intact animals by substituting saline for cocaine in the self-administration component. These results support the hypothesis that the reinforcing effects of cocaine are dependent upon mesolimbic dopamine and demonstrate that cocaine self-administration can be disrupted in animals without altering behavior maintained by a nondrug reinforcer.     

Stability of visceral behavior in the awake rat during rest.

Brady and colleagues have championed the importance of careful delineation and control of a subject's behavioral state. In this paper we develop the concept of visceral behavior from a physiological perspective. Sprague-Dawley rats were instrumented to record arterial blood pressure, renal sympathetic nerve activity, and respiration. The rats were restrained in a conical cloth sock. Rats that were well adapted to the sock restraint showed a regular respiratory pattern and consistent pressure recordings; they rested quietly in the sock and moved only occasionally to adjust their position. Fourier analysis of blood pressure and nerve activity showed a concentration of power below 1 Hz. The coherence between the two signals was strong (0.83 +/- 0.03) at 0.42 Hz. Conversely, during their initial adjustment to the sock restraint, the rats tended to show large fluctuations in blood pressure associated with episodic apneic breathing; 1 animal displayed this pattern of visceral behavior throughout most of the experiment. Despite this instability in pressure, the rats' overt behavior was stable: They rested quietly in the sock with only occasional position shifts. Spectral analysis and coherence computations showed large shifts in the distribution of power and frequency range over which arterial pressure and sympathetic activity were tightly coupled. These data are consistent with the view that an animal's circulatory adjustments, as well as adjustments in other aspects of its physiological state, constitute an important aspect of behavior, and that this behavior can influence the interpretation of biobehavioral data.     

Sexual reinforcement in the female rat.

Sexual reinforcement in the female rat was studied in a preparation that allowed continuous operant responding for access to a male rat leading to intromission. Experiment 1 used a high operant level nose-poke response to test the possible reinforcing effects of some components of access to a male. A simple tone stimulus used as a conditioned reinforcer and two odor stimuli, target male bedding and emulsified preputial gland, were tested. None of these contingent events altered responding above or below operant level. Access to the male, which was always accompanied by intromission, immediately increased response rate when it was made contingent upon the nose-poke response. Performance on fixed-ratio schedules was erratic, and response rate was low in comparison to typical food-reinforced responding. An interresponse-time analysis indicated, however, that some effect of the ratio contingency may have been present. In Experiment 2, several modifications of the procedure were tested with the objective of creating a more tractable preparation for behavior analysis. Response type and the hormone delivery method were changed, and 2 target males were used instead of 1. The latter tripled the average number of reinforcers earned in a single session. Differences between sexual and other reinforcers are discussed in terms of procedural, quantitative, and motivational aspects of the sexual reinforcement procedure.