The parent?infant dyad and the construction of the subjective self

Developmental psychology and psychopathology has in the past been more concerned with the quality of self-representation than with the development of the subjective agency which underpins our experience of feeling, thought and action, a key function of mentalisation. This review begins by contrasting a Cartesian view of pre-wired introspective subjectivity with a constructionist model based on the assumption of an innate contingency detector which orients the infant towards aspects of the social world that react congruently and in a specifically cued informative manner that expresses and facilitates the assimilation of cultural knowledge. Research on the neural mechanisms associated with mentalisation and social influences on its development are reviewed. It is suggested that the infant focuses on the attachment figure as a source of reliable information about the world. The construction of the sense of a subjective self is then an aspect of acquiring knowledge about the world through the caregiver's pedagogical communicative displays which in this context focuses on the child's thoughts and feelings. We argue that a number of possible mechanisms, including complementary activation of attachment and mentalisation, the disruptive effect of maltreatment on parent-child communication, the biobehavioural overlap of cues for learning and cues for attachment, may have a role in ensuring that the quality of relationship with the caregiver influences the development of the child's experience of thoughts and feelings

Long-Term Behavioral Effects of Repetitive Pain in Neonatal Rat Pups

Human preterm neonates are subjected to repetitive pain during neonatal intensive care. We hypothesized that exposure to repetitive neonatal pain may cause permanent or long-term changes because of the developmental plasticity of the immature brain. Neonatal rat pups were stimulated one, two, or four times each day from P0 to P7 with either needle prick (noxious groups N1, N2, N4) or cotton tip rub (tactile groups T1, T2, T4). In groups N2, N4, T2, T4 stimuli were applied to separate paws at hourly intervals;each paw was stimulated only once a day. Identical rearing occurred from P7 to P22 days. Pain thresholds were measured on P16, P22, and P65 (hot-plate test), and testing for defensive withdrawal, alcohol preference, air-puff startle, and social discrimination tests occurred during adulthood. Adult rats were exposed to a hot plate at 62°C for 20 s, then sacrificed and perfused at 0 and 30 min after exposure. Fos expression in the somatosensory cortex was measured by immunocytochemistry. Weight gain in the N2 group was greater than the T2 group on P16 (p < 0.05) and P22 (p < 0.005); no differences occurred in the other groups. Decreased pain latencies were noted in the N4 group [5.0 ± 1.0 s vs. 6.2 ± 1.4 s on P16 (p < 0.05); 3.9 ± 0.5 s vs. 5.5 ± 1.6 s on P22 (p < 0.005)], indicating effects of repetitive neonatal pain on subsequent development of the pain system. As adults, N4 group rats showed an increased preference for alcohol (55 ± 18% vs. 32 ± 21%;p = 0.004); increased latency in exploratory and defensive withdrawal behavior (p < 0.05); and a prolonged chemosensory memory in the social discrimination test (p < 0.05). No significant differences occurred in corticosterone and ACTH levels following air-puff startle or in pain thresholds at P65 between N4 and T4 groups. Fos expression at 30 min after hot-plate exposure was significantly greater in all areas of the somatosensory cortex in the T4 group compared with the N4 group (p < 0.05), whereas no differences occurred just after exposure. These data suggest that repetitive pain in neonatal rat pups may lead to an altered development of the pain system associated with decreased pain thresholds during development. Increased plasticity of the neonatal brain may allow these and other changes in brain development to increase their vulnerability to stress disorders and anxiety-mediated adult behavior. Similar behavioral changes have been observed during the later childhood of expreterm neonates who were exposed to prolonged periods of neonatal intensive care

Endocrine and behavioral effects of airpuff-startle in rats

Adult male rats chronically implanted with cannulae in the jugular vein were used to characterize the endocrine and behavioral consequences of airpuff-startle. In the first series of experiments, resting animals subjected to three blocks of airpuff (blocks of three airpuffs each with each block separated by 1 min) showed a 10-fold increase in plasma adrenocorticotropin (ACTH) and corticosterone levels, indicating a significant but moderate activation of the hypothalamo-pituitary-adrenal (HPA) axis when compared with the untreated controls ( n = 5 each). In the second series of experiments, monitoring of anxiety-related behavior in the defensive withdrawal paradigm revealed a significant increase in anxiety induced by airpuff-startle application compared with the untreated controls ( n = 10 each). This behavioral effect, however, was not correlated with plasma hormone levels, as blood samples taken immediately before and 12 min after exposure to airpuff-startle and exposure to the defensive withdrawal paradigm showed a significant rise in ACTH and corticosterone in both groups. In summary, the findings of the present study indicate that airpuff-startle (1) is a potent stimulus in the activation of the HPA axis, and (2) increases anxiety-related behavior as measured in the defensive withdrawal paradigm. Furthermore, the results of our study support the hypthesis that peripheral endocrine parameters that are used to measure activation of the HPA axis do not necessarily correlate with behavioral data obtained in tests which are thought to measure anxiety