N E van de Poll

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In an attempt to study the possible role of active sleep in brain development, male rats were injected twice daily with chlorimipramine, a potent monoamine reuptake blocker, from 1 week to 3 weeks of postnatal age. AS was reduced to less than 10% of total sleep time, the level found in mature rats. Most of the AS reduction was compensated for by quiet sleep(More)
The role of sex hormones in sexuality and mood across the menstrual cycle was investigated. Twenty-one normal health women were followed for one menstrual cycle. Blood samples were taken frequently, and analyzed for estradiol, progesterone, testosterone, androstenedione, dehydroepiandrosterone sulfate, cortisol, and sex hormone-binding globulin. A diary(More)
The present experiment investigated the effects of exposure to inescapable shocks (IS) on subsequent behavior in an elevated plus-maze and on shuttlebox-escape performance in male and female rats. In the elevated plus-maze, exposure to IS resulted in suppression of "total number of arm entries" and "rearings" in males but not in females. In addition "time(More)
The sex-dependent effects of acute restraint (RT) on nociceptive and pituitary-adrenal responses were investigated in the rat. In a first experiment, the effect of 30 min RT on pain sensitivity was evaluated through repeated use of the tail withdrawal test during and after treatment. RT induced an increase in the nociceptive threshold, i.e., analgesia, in(More)
It is still unclear whether sex differences in cognitive functioning are mainly due to perinatal organizing effects of sex hormones on the brain, or to activating effects in adulthood. In a group of 22 female-to-male transsexuals a battery of visuospatial and verbal ability tests was administered twice: shortly before and 3 months after the start of(More)
Effects of various doses (0-250 micrograms/kg, SC) of estradiol-17 beta (E2) in a two-bottle choice conditioned taste aversion and a two-compartment conditioned place preference procedure were studied in male and female rats. Dose-dependent taste aversion and place aversion effects of E2 were established, and the conditioned taste aversion procedure was(More)
Recently, the vasopressin (AVP) innervation in the rat brain was shown to be restored in senescent rats following long-term testosterone administration. In order to investigate whether this restoration is accompanied by an improvement in learning and memory, both sham- and testosterone-treated young (4.5 months), middle-aged (20 months), and aged (31(More)
The present study investigated 1) the importance of the aromatization process during the perinatal period for the development of the sexually dimorphic nucleus in the preoptic area of the hypothalamus (SDN-POA) of male rats, and 2) the relationship between SDN-POA volume and parameters of masculinization in male rats that were treated perinatally with the(More)
In this article 8 male Wistar rats received bilateral lesions of the medial prefrontal cortex, whereas another 8 rats were control operated. Three weeks after surgery, they were exposed to an autoshaping procedure in which the insertion of a lever into the experimental chamber (conditioned stimulus) always preceded the delivery of a response-independent(More)
A delayed spatial response alternation procedure was used to assess behavioural differences between male and female Wistar rats, assumed to involve memory functioning. In Expt. I, subjects were required to alternate responses between two levers in an operant environment. The delay between response opportunities was varied between 1, 3, 7.5 and 15 s in(More)