1,721,149 research outputs found
Autonomic functions of the cerebellum: Anatomical bases and clinical implications.
No full textTraditionally, the cerebellum is viewed as a center for integrating vestibular
and general proprioceptive sensory, enabling the processing of somatic motor responses essential for maintaining balance and posture. Moreover, the cerebellum regulates
higher motor functions of the neocortex, which involve motor planning and coordination of movements, as well as nonmotor functions related to cognition and affectivity. In recent years, several studies have suggested that the cerebellum may play a role
in regulating visceral functions. Although the specific neural pathways through which
these visceral functions are mediated remain unclear, anatomical evidence to support
these functions has been supplied by the detection of a feedback circuit that connects
bidirectionally the cerebellum and the hypothalamus, the primary integrative center of
the autonomic nervous system. This hypothalamocerebellar circuit strongly supports
the idea of the cerebellum as a center of the autonomic nervous system
VIP-like and GFAP-like immunoreactivities in the chicken brain stem. I. The medulla.
No full textThe aim of the present research is to study the development of spinal ganglia implanted onto chorio-allantoic membrane (CAM), where they are supplied by 'foreign', extraembryonic vessels. Small blocks including a segment of the neural tube and 4 pairs of somites were isolated from the brachial or thoracic or lumbar region (neuromeres C13 - T1 or T3 - T6 or L1 - L4) of thirty 3-day donor chick embryos and grafted on the CAM of as many 10-day host chick embryos. At regular time intervals after grafting, the implants were fixed, embedded in paraffin, serially cross-sectioned and stained. The preliminary results are similar for the ganglia from the 3 regions: they seem to indicate that in the spinal ganglia grafted on the CAM the developing blood vessels do not exert any morphogenetic influence on the substratum; this corroborates results from previous researches (2) on the normally 'in situ' developing ganglia. It is now the author purpose to submit to a careful analysis a datum from the present research: namely, the earlier appearance of the endoganglionic vessels in the brachial and lumbar grafted ganglia than in the thoracic ones
Angiogenesis versus arteriogenesis
No full textIn the vascular system, angiogenesis and arteriogenesis play a unique yet equally important role in both health and disease. Angiogenesis, the formation of new blood vessels from a preexisting vascular bed, occurs naturally during wound healing, the female menstrual cycle and pregnancy. It plays a critical role in tissue growth and repair, and is a highly controlled process that is dependent on an intricate balance of both pro-angiogenic (to stimulate) and anti-angiogenic (to negatively regulate the phenomenon) factors. Otherwise, the term arteriogenesis refers to anatomic transformation of preexisting arterioles with increasing lumen area and wall thickness, due to a thick muscular layer and purchasing of visco-elastic and vasomotor capacities. Arteriogenesis differs from angiogenesis in several aspects, the most important being the dependence of angiogenesis on hypoxia and the dependence of arteriogenesis on inflammation. The expression of growth factors and the cooperation of surrounding and infiltrating cells seem to be essential in orchestrating the complex processes during arteriogenesis
Distribution of Multilayered Fiber Terminals in the Human Cerebellar Cortex. Visualization by Immunohistochemistry for Histamine
Full text linkThe distribution of histamine in the human cerebellar cortex was studied by light microscope immunohistochemistry using a
rabbit polyclonal antibody anti-histamine. In all layers of the cerebellar cortex, were revealed punctate immunoreactive elements
related to putative histaminergic nerve terminals. These findings provide insights into the existence of a histaminergic system in the
human cerebellar cortex, presumably involved in the cerebrocerebellar circuit, the feedback circuit through which the cerebellu
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Medullary and mesencephalic neuronal groups reacting to antibodies against VIP, somatostatin and bombesin in adult Gallus gallus domesticus.
No full textThe caudo-cranially intermediate one-third of medullary dorsal region, the periaqueductal grey and the rostro-ventral portion of the midbrain tegmentum of adult chickens were studied in detail by means of the PAP-DAB procedure, to define further the main morphological features of the neuronal populations that in previous studies had shown VIP (Vasoactive Intestinal Polypeptide),-Somatostatin (SRIF)-, and Bombesin-like immunoreactivities. In the medulla, VIP-like immunoreactivity was detected within neuronal bodies and processes and extended down to the cervical spinal cord. SRIF-like immunoreactivity was seen only within nerve cell processes, at least a part of which could be sensitive fibre terminals. Bombesin-like immunoreactivity was observed only within neuronal processes. In the periaqueductal grey, all 3 immunoreactivities were detected within perikarya and neuronal processes, with a higher density cranially. In the rostro-ventral portion of the midbrain tegmentum, VIP-like and Bombesin-like immunoreactivities were detected (the latter being located somewhat more cranially) both in neuronal bodies and in processes. SRIF-like immunoreactivity was found in this region only in long neuronal processes
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