No abstract

In this study, Fos immunohistochemistry was used to map brainstem neuronal pathways activated during hypercapnia and hypoxia. Conscious rats were exposed to six different gas mixtures: (a) air; (b) 8% CO2 in air; (c) 10% CO2 in air; (d) 15% CO2 in air; (e) 15% CO2 + 60% O2, balance N2; (f) 9% O2, balance N2. Double-staining was performed to show the presence of tyrosine hydroxylase. Hypercapnia, in a dose-dependent way caused Fos expression in the following areas: caudal nucleus tractus solitarius (NTS), with few labeled A2 noradrenergic neurons; noradrenergic A1 cells and noncatecholaminergic neurons in the caudal ventrolateral medulla; raphe magnus and gigantocellular nucleus pars alpha (GiA); many noncatecholaminergic (and relatively few C1) neurons in the lateral paragigantocellular nucleus (PGCl), and in the retrotrapezoid nucleus (RTN); locus coeruleus (LC), external lateral parabrachial and Kölliker-Fuse nuclei, and A5 noradrenergic neurons at pontine level; and in caudal mesencephalon, the ventrolateral column of the periaqueductal gray (vlPAG). In most of these nuclei, hypoxia also induced Fos expression, albeit generally less than after hypercapnia. However, hypoxia did not cause labeling in RTN, juxtafacial PGCl, GiA, LC, or vlPAG. After normoxic hypercapnia, more labeled cells were present in NTS and PGCl than after hyperoxic hypercapnia. Part of the observed labeling could be caused by stress- or cardiovascular-related sequelae of hypoxia and hypercapnia. Possible implications for the neural control of breathing are also discussed, particularly with regard to the finding that several nuclei, not belonging to the classical brainstem respiratory centres, contained labeled cells.

The majority of motives for body donation stem from the wish to be useful after death. However, the present survey suggests that body donation is more than an altruistic act; people are also motivated by personal benefit. Results of our survey contradict the notion that body donation stems from loneliness. Many donors have a supportive social network and meaningful social relationships. People moreover propagate body donation within their social networks.

The authors demonstrated a late neuronal activity in the dorsal horn after exposure of the cervical dorsal root ganglion to different radiofrequency modalities, which was not temperature dependent.

This paper is the first of a projected series of studies on the structure and composition of the medial forebrain bundle (MFB) of the rat and the relations of this fiber system to its bed nucleus, the lateral hypothalamic area. The first part of the paper comprises an extensive review of literature on the MFB from its discovery by Ganser in 1882 to the present. This review serves as the basis for an evaluation of our present-day knowledge of the organization of the MFB, which is presented in the second part of this paper. Despite the wealth of information available on the origins and sites of termination of the axons that constitute the MFB, surprisingly little attention has been given to the bundle itself, to its topographic boundaries, its fiber composition, or to the spatial arrangement of its constituent components. These features of the MFB as it extends through the lateral preoptic and lateral hypothalamic areas have been analyzed in normal Klüver-Barrera- and Bodian-stained material. From this analysis, a detailed atlas of the MFB and some of the surrounding structures has been prepared. This atlas, which forms the third section of this paper, illustrates the appearance and organization of the MFB at ten equidistant levels through the lateral preoptic and lateral hypothalamic continuum.

Please be advised that this information was generated on 2018-05-12 and may be subject to change. BRAIN RESEARCH

No abstract

The intranasal (IN-) administration of substances is attracting attention from scientists as well as pharmaceutical companies. The effects are surprisingly fast and specific. The present review explores our current knowledge about the routes of access to the cranial cavity. 'Direct-access-pathways' from the nasal cavity have been described but many additional experiments are needed to answer a variety of open questions regarding anatomy and physiology. Among the IN-applied substances oxytocin (OT) has an extensive history. Originally applied in women for its physiological effects related to lactation and parturition, over the last decade most studies focused on their behavioral 'prosocial' effects: from social relations and 'trust' to treatment of 'autism'. Only very recently in a microdialysis study in rats and mice, the 'direct-nose-brain-pathways' of IN-OT have been investigated directly, implying that we are strongly dependent on results obtained from other IN-applied substances. Especially the possibility that IN-OT activates the 'intrinsic' OT-system in the hypothalamus as well needs further clarification. We conclude that IN-OT administration may be a promising approach to influence human communication but that the existing lack of information about the neural and physiological mechanisms involved is a serious problem for the proper understanding and interpretation of the observed effects.