Golgi substance

Other Cell Structures. Recently other cell structures have been separated Golgi substance, nucleolus, chromosomes, mitotic apparatus, and secretory granules. The identification of some of these fractions is not certain, and therefore the association of specific enzymes with these structures cannot be made at this time. 

In the trans Golgi compartment the peptide is sorted via secretory vesicles into a regulated pathway. In contrast to vesicles of the constitutive pathway, vesicles of the regulated pathway are stored in the cytoplasm until their stimulated release. Membrane depolarisation as well as a wide range of substances such as intracellular mediators, neuropeptides, neurotransmitters, classical hormones, cytokines, growth factors, ions and nutrients induce somatostatin secretion. General inhibitors of somatostatin release are opiates, GABA, leptin and TGF- 3. 

Like other cells, a neuron has a nucleus with genetic DNA, although nerve cells cannot divide (replicate) after maturity, and a prominent nucleolus for ribosome synthesis. There are also mitochondria for energy supply as well as a smooth and a rough endoplasmic reticulum for lipid and protein synthesis, and a Golgi apparatus. These are all in a fluid cytosol (cytoplasm), containing enzymes for cell metabolism and NT synthesis and which is surrounded by a phospholipid plasma membrane, impermeable to ions and water-soluble substances. In order to cross the membrane, substances either have to be very lipid soluble or transported by special carrier proteins. It is also the site for NT receptors and the various ion channels important in the control of neuronal excitability. 

Organelles Specific particles of membrane-bound organized living substances present in eukaryotic cells, such as the mitochondria the golgi apparatus endoplasmic reticulum lysomomes plastids and vacuoles. [NIH]... 

Over 100 years ago, a debate was raging between the two most famous neuroscientists in the world concerning the nature of the nervous system. Golgi believed that all neurons were connected in a nerve net or syncytium whereas Ramon y Cajal believed that neurons were separated from each other by tiny spaces called synapses. Cajal proved to be correct, and it was later learned that neurons communicate across the synapse by releasing chemical substances known as neurotransmitters or by releasing electrical charges. Because chemical neurotransmission is much more common than electrical transmission, especially in the brain, and it is chemical neurotransmission that is modulated by psychiatric medicines, our discussion will focus on the chemotransmitter process. In simplest terms, the process of chemical neurotransmission occurs in three steps neurotransmitter production, neurotransmitter release, and neurotransmitter action on specific receptors. 

Golgi bodies, which occur in some types of cells. These are flattened bodies of material that serve to hold and release substances produced by the cells. 

Membranes serve to delineate cellular entities, in which case they are termed plasma membranes, and various subcellular particles, such as mitochondria, nuclei, and lysosomes. Such subcellular structures as endoplasmic reticulum and the Golgi apparatus also consist, in large part, of membranous materials. The basic structure of membranes is lipid in nature, and it is the amphipathic nature of such lipid that permits them to aggregate into bilayers. Lipid is not the only component of membranes, however there are protein and carbohydrate components as well. It is these components that function as the means by which hydrophilic substances can cross membranes or that serve as recognition beacons that permit various substances to affect the metabolic activities of cellular and subcellular particles. 

---