scholarly journals Thyrotropin releasing hormone, somatostatin, and enkephalin: distribution studies using immunohistochemical techniques.

1980 ◽  
Vol 28 (4) ◽  
pp. 364-366 ◽  
Author(s):  
O Johansson ◽  
T Hökfelt

Using the indirect immunofluorescence technique of Coons and collaborators, the localization of thyrotropin releasing hormone, somatostatin, and enkephalin was studied in the rat central nervous system. These three peptides were found in neurons throughout the brain and spinal cord; the latter two peptides were also found in the peripheral nervous system and in certain endocrine cells. Utilizing the peroxidase--antiperoxidase technique of Sternberger and collaborators the neuropeptides were also traced at the ultrastructural level. They seemed to be mainly confined to so-called large dense core vesicles (diameter around 1,000 A), localized within cell bodies and nerve terminals.

Author(s):  
Grazia Tagliafierro ◽  
Cristiana Crosa ◽  
Marco Canepa ◽  
Tiziano Zanin

Barnacles are very specialized Crustacea, with strongly reduced head and abdomen. Their nervous system is rather simple: the brain or supra-oesophageal ganglion (SG) is a small bilobed structure and the toracic ganglia are fused into a single ventral mass, the suboesophageal ganglion (VG). Neurosecretion was shown in barnacle nervous system by histochemical methods and numerous putative hormonal substances were extracted and tested. Recently six different types of dense-core granules were visualized in the median ocellar nerve of Balanus hameri and serotonin and FMRF-amide like substances were immunocytochemically detected in the nervous system of Balanus amphitrite. The aim of the present work is to localize and characterize at ultrastructural level, neurosecretory neuron cell bodies in the VG of Balanus amphitrite.Specimens of Balanus amphitrite were collected in the port of Genova. The central nervous system were Karnovsky fixed, osmium postfixed, ethanol dehydrated and Durcupan ACM embedded. Ultrathin sections were stained with uranyl acetate and lead citrate. Ultrastructural observations were made on a Philips M 202 and Zeiss 109 T electron microscopy.


Author(s):  
J. Eric Ahlskog

As a prelude to the treatment chapters that follow, we need to define and describe the types of problems and symptoms encountered in DLB and PDD. The clinical picture can be quite varied: problems encountered by one person may be quite different from those encountered by another person, and symptoms that are problematic in one individual may be minimal in another. In these disorders, the Lewy neurodegenerative process potentially affects certain nervous system regions but spares others. Affected areas include thinking and memory circuits, as well as movement (motor) function and the autonomic nervous system, which regulates primary functions such as bladder, bowel, and blood pressure control. Many other brain regions, by contrast, are spared or minimally involved, such as vision and sensation. The brain and spinal cord constitute the central nervous system. The interface between the brain and spinal cord is by way of the brain stem, as shown in Figure 4.1. Thought, memory, and reasoning are primarily organized in the thick layers of cortex overlying lower brain levels. Volitional movements, such as writing, throwing, or kicking, also emanate from the cortex and integrate with circuits just below, including those in the basal ganglia, shown in Figure 4.2. The basal ganglia includes the striatum, globus pallidus, subthalamic nucleus, and substantia nigra, as illustrated in Figure 4.2. Movement information is integrated and modulated in these basal ganglia nuclei and then transmitted down the brain stem to the spinal cord. At spinal cord levels the correct sequence of muscle activation that has been programmed is accomplished. Activated nerves from appropriate regions of the spinal cord relay the signals to the proper muscles. Sensory information from the periphery (limbs) travels in the opposite direction. How are these signals transmitted? Brain cells called neurons have long, wire-like extensions that interface with other neurons, effectively making up circuits that are slightly similar to computer circuits; this is illustrated in Figure 4.3. At the end of these wire-like extensions are tiny enlargements (terminals) that contain specific biological chemicals called neurotransmitters. Neurotransmitters are released when the electrical signal travels down that neuron to the end of that wire-like process.


1991 ◽  
Vol 54 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Toshiaki Ishiguro ◽  
Akihisa Iguchi ◽  
Yasuo Kunoh ◽  
Minehiro Goto ◽  
Kazumasa Uemura ◽  
...  

Author(s):  
G.O. Mackie

Ciona intestinalis has a well developed nerve plexus associated with the dorsal strand, as first described by Marco Fedele. The dorsal strand plexus is immunoreactive with antisera against gonadotropin-releasing hormone. Immunoreactivity is seen in the cell bodies, which lie peripherally, and in processes which run throughout the dorsal blood sinus, enter the branchial sac and penetrate the brain via the visceral nerve. The plexus provides a rich innervation of the gonoducts, and processes have been seen in the gonads. The pericardium is not innervated by processes from the plexus and the rectum is poorly innervated, but the full extent of the plexus in the viscera remains uncertain. While this study confirms many of Fedele's observations, it does not support the view that the dorsal strand plexus is equivalent to the vertebrate visceral nervous system.


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