BRAIN BIOGENIC AMINES IN MENTAL DYSFUNCTIONS ATTRIBUTABLE TO THYROID HORMONE ABNORMALITIES
2
Citation
183
Reference
10
Related Paper
Forebrain
Catecholaminergic cell groups
Phenylethanolamine N-methyltransferase
Cite
Citations (0)
Acetylcholine, the first chemical to be identified as a neurotransmitter, is packed in synaptic vesicles by the activity of VAChT (vesicular acetylcholine transporter). A decrease in VAChT expression has been reported in a number of diseases, and this has consequences for the amount of acetylcholine loaded in synaptic vesicles as well as for neurotransmitter release. Several genetically modified mice targeting the VAChT gene have been generated, providing novel models to understand how changes in VAChT affect transmitter release. A surprising finding is that most cholinergic neurons in the brain also can express a second type of vesicular neurotransmitter transporter that allows these neurons to secrete two distinct neurotransmitters. Thus a given neuron can use two neurotransmitters to regulate different physiological functions. In addition, recent data indicate that non-neuronal cells can also express the machinery used to synthesize and release acetylcholine. Some of these cells rely on VAChT to secrete acetylcholine with potential physiological consequences in the periphery. Hence novel functions for the oldest neurotransmitter known are emerging with the potential to provide new targets for the treatment of several pathological conditions.
Vesicular acetylcholine transporter
Neurotransmitter Agents
Neurotransmitter transporter
Synaptic cleft
Cite
Citations (122)
Acetylcholine (ACh) was the first biological substance to be identified as a neurotransmitter. In spite of this relatively long history, the functions of acetylcholine in biological systems are still in the process of being elucidated. In the retina, which is responsible for the receipt and initial processing of light information for use by the visual system, acetylcholine has at least two functions: as a neurotransmitter and as an important molecule helping to organize the development of retinal cells.
Neurotransmitter Agents
Cite
Citations (0)
Cite
Citations (80)
ABSTRACT Background Acetylcholine is a cell signaling molecule that has been identified in plants, bacteria, and metazoans to play multiple roles in cells and as a neurotransmitter capable of exciting both neurons and muscle. While cell-cell communication activity has been reported in all phyla that have been investigated, its role as a neurotransmitter is less clear. Work within cnidarians implies that neurotransmitter activity emerged within or prior to the emergence of the cnidarian-bilaterian ancestor, but whether or not it is able to excite both muscles and neurons has not been addressed. Results To investigate the evolution of acetylcholine signaling we characterized the expression pattern of acetylcholine receptors (AchRs) and the neurotransmitter activity of acetylcholine in Nematostella vectensis . Expression patterns for 13 of the 21 known NvAchRs are consistent with acetylcholine acting as a cell signaling molecule and a neurotransmitter in neurons, muscles, or both. To dissect neurotransmitter activity we investigated the mechanism by which acetylcholine activates tentacular contractions in Nematostella . Tentacular contractions induced by application of acetylcholine are suppressed by inactivating voltage gated sodium channels with lidocaine indicating that acetylcholine specifically activates neurons in the tentacular contractile circuit. Conclusion Our results verify that acetylcholine’s neurotransmitter activity emerged prior to cnidarian-bilaterian divergence and that non-neuronal roles were likely retained in Nematostella . Additionally, we found no evidence to support a muscle activating role for acetylcholine indicating that its role in muscle excitability evolved during bilaterian evolution.
Neurotransmitter receptor
Cite
Citations (3)
Acetylcholine is an important neurotransmitter that relays neural excitation from lower motor neurons to muscles. It also plays significant roles in the central nervous system by modulating neurotransmission. However, there is a lack of tools to directly measure the quantity and distribution of acetylcholine at the subcellular level. In this Communication, we demonstrate for the first time that label-free imaging of acetylcholine is achieved with frequency-modulated spectral-focusing stimulated Raman scattering (FMSF-SRS) microscopy: a technical improvement over traditional SRS microscopy that effectively removes imaging backgrounds. Moreover, we directly quantified the local concentration of acetylcholine at the neuromuscular junction of frog cutaneous pectoris muscle.
Cite
Citations (88)
Innervation of the mammalian thymus gland by both cholinergic and catecholaminergic neuronal projections has been documented. The present results reveal that the inhibitory neurotransmitter, gamma amino butyric acid is also present in the mouse thymus and that it is significantly elevated following challenge with a T-cell dependent antigen. A possible immunomodulatory role for the neurotransmitter is discussed.
Catecholaminergic cell groups
Cite
Citations (7)
Measurements of the specific activity of norepinephrine in coronary sinus blood were made in intact dogs from 20 minutes to 48 hours after the endogenous norepinephrine pool had been labeled with tritiated norepinephrine. The specific activity in blood was observed to decline sharply during augmented release of norepinephrine into the blood either by tyramine administration or nerve stimulation in all experiments up to 5 hours after labeling the neurotransmitter pool. Although the values in blood more nearly approximated the specific activity measured simultaneously in the heart during augmented release, they were still consistently greater than tissue values. At 24 and 48 hours after labeling the pool, no change in specific activity in blood was observed after administration of tyramine or nerve stimulation and the values in blood and tissue showed no differences. These findings are interpreted to indicate that exogenous norepinephrine initially mixes with a portion of the neurotransmitter store which is in more rapid exchange with the blood and only slowly equilibrates with the entire store. This is presented as further evidence for considering the neurotransmitter pool to be nonhomogeneous.
Tyramine
Cite
Citations (37)
Acetylcholinesterase (Ache, EC 3.1.1.7) is a substrate specific enzyme that catalyzes the hydrolysis of the neurotransmitter acetylcholine (Ach) in the nerve synapses. Hydrolysis of the neurotransmitter leads to decrease in the concentration of the acetylcholine. An optimum level of Ach should be maintained in the brain for its proper function. An increased and decreased level of Ach hampers the functioning of brain. Thus Ache performs a critical function in the nervous system of all organisms including insects. Any impairment of Ache action leads to imbalance in the nervous system and will be fatal for organism concerned. Therefore, Ache seems to be an attractive target for identifying receptor specific insecticides. The present study is focused on finding the more efficient inhibitors for Ache through virtual high-throughput screening methods.
Neurotransmitter receptor
Cite
Citations (0)
The motility of the oviduct is not just the cellular interplay,but there are complex underlying phenomenon brought about by the specific molecules,the neurotransmitters that drive this activity in a highly organized manner.Acetylcholine is an important excitatory neurotransmitter that causes the contraction of smooth muscle.We have demonstrated the localization of acetylcholine in oviductal
Oviduct
Cite
Citations (0)