Recent findings in chronically instrumented animals challenge the classic concept that baroreflexes do not play a role in the chronic regulation of arterial pressure. As alterations in renal excretory function are of paramount importance in the chronic regulation of arterial pressure, several of these recent studies have focused on the long-term interactions between the baroreflex and the kidneys during chronic perturbations in arterial pressure and body fluid volumes. An emerging body of evidence indicates that the baroreflex is chronically activated in several experimental models of hypertension, but in most cases, the duration of these studies has not exceeded 2 wk. Although these studies suggest that the baroreflex may play a compensatory role in attenuating the severity of the hypertension, possibly even in primary hypertension with uncertain causes of sympathetic activation, there has been only limited assessment of the quantitative importance of this interaction in the regulation of arterial pressure. In experimental models of secondary hypertension, baroreflex suppression of renal sympathetic nerve activity is sustained and chronically promotes sodium excretion. This raises the possibility that the renal nerves may be the critical efferent link for baroreceptor-induced suppression of central sympathetic output through which long-term compensatory reductions in arterial pressure are produced. This contention is supported by strong theoretical evidence but must be corroborated by experimental studies. Finally, although it is now clear that pressure-induced increases in baroreflex activity persist for longer periods of time than previously suggested, studies using new tools and novel approaches and extending beyond 2 wk of hypertension are needed to elucidate the true role of the baroreflex in the pathogenesis of clinical hypertension.

We investigated associations between children's representations of mothers in their play narrative and measures of children's and mothers' socioemotional adaptation, and explored the development of these representations between the ages of 4 and 5 years. Fifty-one children were interviewed using the MacArthur Story-Stem Battery to obtain their narrative representations of mothers. Positive, Negative, and Disciplinary representation composites were generated. Children who had more Positive and Disciplinary representations and fewer Negative representations had fewer behavior problems and their mothers reported less psychological distress. In addition, 5-year-olds had more Positive and Disciplinary representations and fewer Negative representations than did 4-year-olds, and there was moderate stability in individual differences in children's representations of mothers across the 2 ages. The results add an important dimension to research on parent-child relationships--that of children's perspectives on these relationships.

Abstract-Recent studies indicate that renal sympathetic nerve activity is chronically suppressed in angiotensin (Ang II) hypertension and that baroreflexes play a critical role in mediating this response. To support these findings, we determined whether the hypertension associated with chronic infusion of Ang II at 4.8 pmol/kg per minute (5ng/kg per minute) produces sustained activation of medullary neurons that participate in the central baroreceptor reflex pathway. We used Fos-like (Fos-Li) protein immunohistochemical methods to determine activation of neurons in the nucleus tractus solitarius (NTS), caudal ventrolateral medulla (CVLM), and rostral ventrolateral medulla (RVLM). Results were compared in three groups of chronically instrumented dogs subjected to infusion of: 1) saline (control); 2) Ang II-2 hours (acute); and 3) Ang II-5 days (chronic here has been a long-standing interest in the mechanisms that contribute to the hypertension induced by pathophysiological levels of angiotensin (Ang II) in the circulation. Although circulating Ang II has sustained actions on the kidneys, vasculature, and adrenal glands that promote chronic hypertension, acute studies have also demonstrated that circulating Ang II can act in the central nervous system to increase sympathetic activity and arterial pressure. 1 However, the relevance of these acute studies to the pathophysiological role of Ang II in hypertension has not been settled. In large part, this is because of technical limitations that prevent determination of both the long-term changes in sympathetic activity and the sustained influence of the sympathetic nervous system on renal excretory function.It is well established that the kidneys play a critical role in the long-term regulation of arterial pressure. 2 The few studies that have determined the temporal changes in renal sympathetic nerve activity and the resultant neurally-induced renal excretory responses during chronic Ang II infusion strongly indicate interactions between the renin-angiotensin and sympathetic nervous systems in the genesis of the hypertension. [3][4][5][6][7] In direct opposition to the notion that the sympathetic nervous system contributes to Ang II hypertension, these studies indicate that suppression of renal sympathetic nerve activity and attendant increases in sodium excretion are sustained responses in Ang II hypertension. 3-7 These findings therefore suggest that the sympathetic nervous system actually attenuates rather than contributes to the severity of Ang II hypertension. Furthermore, based on a recent study in chronically instrumented dogs, it seems that chronic renal sympathoinhibition in Ang II hypertension is mediated by baroreflexes. 6 As it is well established that baroreceptors undergo rapid adaptation and resetting, 8 this recent study is rather surprising. In fact, the implication of this study is that the baroreflex does not completely reset in chronic hypertension and, therefore, may play a role in the chronic regulation of arterial pressure. The primary object...

The superior colliculus (SC), which directs orienting movements of both the eyes and head, is reciprocally connected to the mesencephalic reticular formation (MRF), suggesting the latter is involved in gaze control. The MRF has been provisionally subdivided to include a rostral portion, which subserves vertical gaze, and a caudal portion, which subserves horizontal gaze. Both regions contain cells projecting downstream that may provide a conduit for tectal signals targeting the gaze control centers which direct head movements. We determined the distribution of cells targeting the cervical spinal cord and rostral medullary reticular formation (MdRF), and investigated whether these MRF neurons receive input from the SC by the use of dual tracer techniques in Macaca fascicularis monkeys. Either biotinylated dextran amine or Phaseolus vulgaris leucoagglutinin was injected into the SC. Wheat germ agglutinin conjugated horseradish peroxidase was placed into the ipsilateral cervical spinal cord or medial MdRF to retrogradely label MRF neurons. A small number of medially located cells in the rostral and caudal MRF were labeled following spinal cord injections, and greater numbers were labeled in the same region following MdRF injections. In both cases, anterogradely labeled tectoreticular terminals were observed in close association with retrogradely labeled neurons. These close associations between tectoreticular terminals and neurons with descending projections suggest the presence of a trans-MRF pathway that provides a conduit for